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Sorbents are promising materials for applications in atmospheric water harvesting, thermal energy storage, and passive cooling, thereby addressing central challenges related to water scarcity and the global energy transition. Recently, hygroscopic hydrogel composites have emerged as high‐performance sorbents. However, many of these systems are fabricated with unsustainable and costly sorbent materials, which hinders their wide deployment. Here, the synthesis of high‐performance, cost‐efficient polyacrylamide hydrogels loaded with unprecedented amounts of calcium chloride is demonstrated. To this end, the swelling procedure of polyacrylamide hydrogels in aqueous calcium chloride solutions is optimized. The achievable salt loading in the hydrogel is characterized as a function of temperature, calcium chloride concentration in the swelling solution, and the hydrogel preparation conditions. The obtained hydrogel‐salt composites are shown to be stable under repeated sorption‐desorption cycling and enable water uptakes of 0.92 and 2.38 grams of water per gram of dry materials at 30% and 70% relative humidity, respectively. The resulting cost‐performance ratio substantially exceeds lithium chloride‐based systems. Further, the mechanistic insights on hydrogel salt interactions can guide the design of sustainable and low‐cost sorbent materials for future applications in water and energy. [ABSTRACT FROM AUTHOR]

Nonconventional luminescent polymers have become research hotspots due to their advantages such as persistent room temperature phosphorescence (p‐RTP) emission and strong film‐forming properties. It is proven that the molecular weight (MW) of such luminescent polymers has a significant impact on their emission over a large range, generally with a red shift as the MW increases. Herein, four controllable MW polyacrylamides are prepared via reversible addition‐fragmentation chain transfer polymerization (RAFT), and their photoluminescence quantum yield and p‐RTP lifetimes gradually increase with the increasing MW. The emission of p‐RTP gradually shifts blue with increasing MW, which is likely due to the gradually changing interactions between the electron‐rich portion in RAFT reagent and the increasing acrylamide (AM) units in the molecular chain. These can be reasonably explained through small angle X‐ray scattering, the clustering‐triggered emission (CTE) mechanism, and supported by theoretical calculations. Powder with controllable p‐RTP capability has the potential for strategic anti‐counterfeiting encryption. The above results not only promote the development of the CTE mechanism toward more precise explanations but also provide new ideas for the preparation of nonconventional luminescent polymers with controllable p‐RTP emission performance. [ABSTRACT FROM AUTHOR]

In the past, polyacrylamide hydrogel was a popular choice for breast augmentation filler, and many women underwent mammoplasty with this gel. However, due to frequent complications, the use of polyacrylamide hydrogel in mammoplasty has been banned. Despite this ban, patients experiencing complications still seek medical treatment. The aim of this study was to investigate the fate of the polymer over a defined implantation period. Biopsies of breast implants were obtained from patients with 23 and 27 years of post-mammoplasty. These biopsies were meticulously purified from biological impurities and subjected to analysis using IR spectrometry, liquid chromatography—mass spectrometry, gas chromatography, and differential scanning calorimetry. The findings revealed the presence of polyacrylamide hydrogel residues, along with degradation products, within the infected material. Notably, the low-molecular-weight degradation products revealed via gas chromatography are aggressive and toxic substances capable of inducing chronic inflammation. This study sheds light on the long-term consequences of polyacrylamide hydrogel implantation, highlighting the persistence of harmful degradation products and their role in exacerbating patient complications. [ABSTRACT FROM AUTHOR]

Excessive phosphorus in aqueous solutions can cause eutrophication, which can harm aquatic organisms and pose a risk to the safety of drinking water for humans. The Chitosan/Polyacrylamide/Lanthanum (CS/PAM/La) hydrogel was designed to get rid of phosphate from aqueous solutions. La (III) was used to enhance the capacity of adsorption of CS. Polyacrylamide was used to enhance the mechanical properties of CS. The results showed that the adsorption capacity of CS/PAM/La hydrogel for phosphate was increased compared with that of CS. When pH of 5.0, the adsorption capacity was 80.07 mg-P/g. In addition, after five adsorption and desorption cycles, the adsorption efficiency remained above 90%. The mechanism of phosphate adsorption on CS/PAM/La material was analyzed using a mass transfer factor model (MTF) and the possible structure of CS/PAM/La hydrogel was calculated by density functional theory calculation (DFT). The application of CS/PAM/La composite hydrogel for removal of phosphate from actual wastewater was investigated, and the results met the requirement of national standard. [ABSTRACT FROM AUTHOR]

Based on the requirements of deep sealing and profile control for the excellent temperature and salt resistance on polyacrylamide microspheres, the Poly‐AM/AMPS was prepared depends on aqueous solution polymerization method to improving oil and gas recovery efficiency in low‐permeability and heterogeneous reservoirs resulted by water channeling. The key technical parameters were established through single‐factor experimental methods, and the chemical structure was studied by infrared spectrum analysis (FTIR), energy spectrum analysis, and x‐ray diffraction analysis, and then the thermal stability was investigated depends on the thermogravimetric (TG) and differential thermogravimetric (DTG) distribution curves, moreover, the particle size and distribution, microstructure, and surface morphology were further studied. As a result, the results confirmed that the molecular structure of Poly‐AM/AMPS meets the expected design, and the quality retention rate at 800°C is 17.4%, the median particle size of Poly‐AM/AMPS particles is 35.88 μm, and the particle size distribution range is about 1.94–497.8 μm. Further, the Poly‐AM/AMPS was modified by maleic anhydride, sodium styrenesulfonate, and dimethyl diallyl ammonium chloride through conventional functional strengthening and modification, modified by nano‐SiO2, GO, and S‐CaCO3 through nano‐functional strengthening and modification. Additionally, the functional strengthening and modification mechanism was studied depends on the FTIR, TG, and DTG methods. [ABSTRACT FROM AUTHOR]

Outstanding overall mechanical properties are essential for the successful utilization of hydrogels in advanced applications such as human-machine interfaces and soft robotics. However, conventional hydrogels suffer from fracture toughness-stiffness conflict and fatigue threshold-stiffness conflict, limiting their applicability. Simultaneously enhancing the fracture toughness, fatigue threshold, and stiffness of hydrogels, especially within a homogeneous single network structure, has proven to be a formidable challenge. In this work, we overcome this challenge through the design of a loosely cross-linked hydrogel with slight dehydration. Experimental results reveal that the slightly-dehydrated, loosely cross-linked polyacrylamide hydrogel, with an original/current water content of 87%/70%, exhibits improved mechanical properties, which is primarily attributed to the synergy between the long-chain structure and the dense dehydration-induced entanglements. Importantly, the creation of these microstructures does not require intricate design or processing. This simple approach holds significant potential for hydrogel applications where excellent anti-fracture and fatigue-resistant properties are necessary. For use in a range of applications, hydrogel properties are vital, but it can be challenging to balance different aspects. Here, the authors report the use of a dehydration strategy to prepare hydrogels with desirable fracture toughness, fatigue threshold, and modulus. [ABSTRACT FROM AUTHOR]

Many CRISPR-Cas immune systems generate guide (g)RNAs using trans-activating CRISPR RNAs (tracrRNAs). Recent work revealed that Cas9 tracrRNAs could be reprogrammed to convert any RNA-of-interest into a gRNA, linking the RNA's presence to Cas9-mediated cleavage of double-stranded (ds)DNA. Here, we reprogram tracrRNAs from diverse Cas12 nucleases, linking the presence of an RNA-of-interest to dsDNA cleavage and subsequent collateral single-stranded DNA cleavage—all without the RNA necessarily encoding a protospacer-adjacent motif (PAM). After elucidating nuclease-specific design rules, we demonstrate PAM-independent RNA detection with Cas12b, Cas12e, and Cas12f nucleases. Furthermore, rationally truncating the dsDNA target boosts collateral cleavage activity, while the absence of a gRNA reduces background collateral activity and enhances sensitivity. Finally, we apply this platform to detect 16 S rRNA sequences from five different bacterial pathogens using a universal reprogrammed tracrRNA. These findings extend tracrRNA reprogramming to diverse dsDNA-targeting Cas12 nucleases, expanding the flexibility and versatility of CRISPR-based RNA detection. Cas12 nucleases offer powerful tools for RNA-guided DNA detection. Here, Jiao et al. show that these same nucleases can be harnessed for sensitive and specific RNA detection by reprogramming their associated RNA processing factors called tracRNAs. [ABSTRACT FROM AUTHOR]

Acrylamide is an important chemical in great global demand for the synthesis of polyacrylamide. A facile and benign approach of concentrating high osmotic acrylamide aqueous solution at a low temperature is needed to replace the current energy-intensive and cost-expensive thermal flash evaporation process. For the first time, a multi-stage forward osmosis (FO) process has been developed to concentrate acrylamide solution from 200 g/L to 600 g/L. Thin-film composite (TFC) membrane was fabricated and used for the multi-stage FO process. Acrylamide feed solution (FS) with various concentrations was systematically characterized in terms of viscosity and osmotic pressure (OP). Draw solutes including NaCl and MgCl2 were tested, and their reverse salt fluxes were measured with the quantification of their accumulative contents in the resultant concentrated acrylamide solution. Different operation modes including AL-FS (active layer facing FS) and AL-DS (active layer facing DS) were explored to optimize the system efficiency of the FO concentration process. Both single- and multi-stage FO operations were investigated, and their performances were quantified to assess the efficiency of the concentration of acrylamide solution. The results demonstrate that the multi-stage FO operation could dramatically improve the system efficiency for the concentration of acrylamide solution better than the single-stage FO process, and the draw concentration renewal at Stages II, III, and IV led to a water flux increase of 18.56%, 17.52%, and 18.43%, respectively. Moreover, the accumulated MgCl2 in the final 600 g/L acrylamide solution was below 3.7 g/L, less than 0.62 wt% impurity in the product of acrylamide. Our work provides a practical insight into the viability and optimization of a multi-stage FO process for concentrating high osmotic chemicals. [ABSTRACT FROM AUTHOR]

Gels as compelling soft material shows its promising versatility in actuators, soft electronics, and biomedical sensors. However, most gel materials are too rigid to cope with long‐term changing scenarios and specific needs. Inspired by the switchable behavior of bio‐behavior of muscle, the study reports a thermodynamically controllable and stiffness‐transformative cellulose‐salt gel by simple thermal mixing of hydrous salt, cellulose nanofiber, and polyacrylamide. The achieved cellulosic gel with dynamic microstructure presents an amazing stiffness switchability between crystalline state and melted states of 32.38 to 0.02 MPa, as well as the regulable light transmittance between 41.59% and 93.43%. In addition, this cellulose‐salt gel has excellent thermal controllable behavior. That is, by controlling the crystallization process, the cellulose‐salt gel displays the start‐stop releasing‐energy behaviors on demand. Enabled by these outstanding properties, the study further demonstrates the promising application of cellulose‐salt gel in controllable soft‐rigid coupling thermoelectric device, showing the broader implications for wearable electronics aiming at on‐demand work. [ABSTRACT FROM AUTHOR]

AbstractA novel inorganic-organic composite flocculant polyferric titanium silicate/chitosan (PFTS/CTS) was successfully synthesized in this study. The optimal preparation parameters of flocculant were optimized by orthogonal experiment with organic polymer polyacrylamide (PAM) removal rate as the evaluation index. The results shows that the examined preparation parameters are in the order of aging time > m(Fe + Ti):m(CTS) > n(Fe + Ti):n(Si), and the best experimental formula is that aging time = 2 days, m(Fe + Ti):m(CTS)=5 and n(Fe + Ti):n(Si)=0.5. The obtained PAM (50 mg/L) removal rate is 78.7% under the selected suitable wastewater treatment condition. Compared with the single CTS, PFTS and polyferric silicate (PFS), PFTS/CTS exhibits superior flocculation performance. The reason for the improvement of flocculation performance of PFTS/CTS can be attributed to its good crystallinity, special scaly accumulation structure and high positive charge, as well as the synergistic effect of inorganic flocculant and organic flocculant in the PFTS/CTS flocculant, which is successfully composited through coordination bond between titanium ions of PFTS and hydroxyl or amino groups of CTS. The main mechanism of treating PAM by PFTS/CTS is physical and chemical effect including micro-flocs are formed through chelate, charge neutralization and adsorption in the first process, and then the larger particles are formed by bridging, wrapping and sweeping. In addition, the flocs of treating PAM using PFTS/CTS are dense and large, its formation and the sedimentation are fast. The prepared flocculant exhibits eminent application prospects in the field of PAM wastewater. [ABSTRACT FROM AUTHOR]

Water recycling in mining is essential to decrease water usage, which results in the accumulation of high concentrations of inorganic and organic substances in the process water. Consequently, adverse impacts on the flotation process of copper sulfides may arise. High-molecular-weight polymers based on anionic polyacrylamides (PAMs) are used as tailing flocculants in mineral processing plants. The recirculation of water recovered from the tailing thickeners to the flotation process introduces residual PAMs, which can impact the flotation of important copper sulfides like chalcopyrite, bornite, and enargite. This issue has been rarely studied. In this work, results on the effect of an anionic polyacrylamide (PAM) of medium–low anionicity on the flotation of chalcopyrite, enargite, and bornite are reported and analyzed. The results show that PAM molecules depress the flotation of chalcopyrite, enargite, and bornite under a wide range of pH values. The experimental data indicate that the depressing effect of PAMs on copper sulfides increases with pH. The zeta potential results reveal that this parameter becomes less negative with the addition of PAMs, indicating interactions between PAM molecules and the surfaces of the copper sulfides. PAM adsorption on copper sulfides increases with pH, which correlates with the flotation and zeta potential data. It is proposed that the interactions between PAM molecules and copper sulfides are explained by the presence of surface iron and copper hydroxides that create chemically active adsorption sites. [ABSTRACT FROM AUTHOR]

Recoverable and humidity‐tolerant colorimetric sensors are extremely difficult to overcome. In this work, a composite hydrogel sensor based on chelation reaction is proposed for the first time to achieve ultra‐fast recovery and ultra‐low detection limit (LOD) of H2S colorimetric sensing. The composite hydrogel sensor is constructed by polyvinyl alcohol/boric acid/Pb2+ (PVA/Bn/Pb) hydrogel sensing layer and polyacrylamide/sodium alginate (PAM/SA) hydrogel adsorption layer. The change from white to brown is achieved in H2S and can be restored when placed in the air. The response/recovery mechanism is explained by the transfer of Pb2+ between hydrogels and the formation of an “Alginate‐Pb2+” with egg‐box structure during the process. The multimodal fusion deep neural network (MF‐DNN) can overcome the error caused by hydrogel aging. Due to the excellent loading and diffusion function provided by the 3D structure of hydrogel, the sensor has a broad detection range of 0.2–100 ppm, a response/recovery time of 10s/32s, and a theoretical LOD of 0.026 ppm. A smartphone‐based H2S sensing system is developed to enable non‐invasive halitosis diagnosis, egg freshness detection, and remote H2S monitoring and alarming. The system is recoverable, humidity‐tolerant, capable of ultrafast detection and widely applicable. This work provides inspiration for humidity‐tolerant and recoverable H2S gas sensing. [ABSTRACT FROM AUTHOR]

Hydrogel coatings, with natural tissue‐like mechanical and biological compatibility, demonstrate promise for bulk material applications. However, existing coating methods lack efficiency and control, especially when dealing with complex geometries, diverse substrate materials, and varying sizes. In this study, an enzyme‐immobilized surface‐catalyzed cross‐link approach is proposed for the growth of hydrogel coatings on multiple substrates, accommodating various materials and shapes. The hydrogel coating is formed through the catalytic action of interface‐immobilized enzymes, which induce the crosslinking of hyaluronic acid, and its mechanical properties are further enhanced by introducing a secondary polyacrylamide network. This approach enables the controlled growth of conformal double network hydrogel coatings with a desired thickness on a wide range of substrate surfaces and devices. Notably, the hydrogel coating exhibits remarkable lubricity and anti‐thrombotic properties, especially desire for medical intervention devices. This advancement offers a universal route to impart biocompatible soft interfaces to bulk materials or devices. [ABSTRACT FROM AUTHOR]

Aqueous zinc (Zn) battery with remarkable advantages of high safety, low cost, and high reversibility is highly applauded in next‐generation low‐speed electric vehicles and large‐scale energy storage applications. However, Zn anode suffers from a series of unfavorable reactions, hindering its progress toward industrialization. Herein, a functionalized hydrogel film is designed using polydopamine and polyacrylamide crosslinking (PDAM) as the Zn protective layer to stabilize the Zn anode. Benefiting from the strong interaction of Zn2+ with PDAM, the primary solvation shell of Zn2+ is regulated by PDAM into the form of PDAM–Zn2+‐5H2O. This remodeling prevents Zn dendrite growth and inhibits water‐induced side reactions. As a result, the Zn–MnO2 battery using PDAM‐coated Zn anode exhibits excellent cycling stability, demonstrating over 1150 cycles at an areal capacity of 5 mAh cm−2 with an average Coulombic efficiency (CE) of 96.5%. For a scaled‐up PDAM@Zn–MnO2 pouch cell with a capacity of 80 mAh, stable cycling of over 200 cycles with an average CE of 91.9% is achieved. The superior Zn–MnO2 battery enabled by the functionalized hydrogel protective film enlightens an arena toward next‐generation energy storage applications. [ABSTRACT FROM AUTHOR]

Over recent decades, there has been a documented rise in natural organic matter (NOM) levels in surface waters globally, adversely affecting drinking water treatment processes. This study is focused on employing adsorption techniques to explore the removal of proteinaceous NOM from an aqueous solution. A chitosan/polyacrylamide (chitosan/PAM) hydrogel was synthesized through a multi-step procedure involving chitosan and acrylamide solutions preparation, polymerization initiation, mixing, gelation, purification, and drying. The Fouriertransform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) techniques were employed to characterize the synthesized chitosan/PAM hydrogel, examining its structural and morphological features. Adsorption experiments were conducted to assess performance of chitosan/PAM hydrogel adsorbent for the removal of bovine serum albumin (BSA) from aqueous solutions. Various physical parameters including temperature, time, pH, initial BSA concentration, and adsorbent dosage were examined in batch experiments. The adsorption capacity of chitosan/PAM hydrogel for BSA and removal percent of BSA was found 617 mg/g and 77.2 % at 6 h under optimum conditions (T= 25ºC and pH=7) with kinetic studies indicating a best fit with the pseudo-1st-order model. Isotherm studies demonstrated that the Temkin isotherm model best fitted with experimental BSA adsorption data (R2 > 0.99). The findings underscore the efficacy of the developed adsorbent in efficiently removing natural proteins. Furthermore, the experimental results indicate that the adsorption capacity of the chitosan/PAM hydrogel augmented with rising temperature and initial BSA concentration. [ABSTRACT FROM AUTHOR]

Certain miRNAs, notably miR29c, demonstrate a remarkable capacity to regulate cellular osteogenic differentiation. However, their application in tissue regeneration is hampered by their inherent instability and susceptibility to degradation. In this study, we developed a novel miR29c delivery system utilising tetrahedral framework nucleic acids (tFNAs), aiming to enhance its stability and endocytosis capability, augment the efficacy of miR29c, foster osteogenesis in bone marrow mesenchymal stem cells (BMSCs), and significantly improve the repair of critical‐sized bone defects (CSBDs). We confirmed the successful synthesis and biocompatibility of sticky ends‐modified tFNAs (stFNAs) and miR29c‐modified stFNAs (stFNAs‐miR29c) through polyacrylamide gel electrophoresis, microscopy scanning, a cell counting kit‐8 assay and so on. The mechanism and osteogenesis effects of stFNAs‐miR29c were explored using immunofluorescence staining, western blotting, and reserve transcription quantitative real‐time polymerase chain reaction. Additionally, the impact of stFNAs‐miR29c on CSBD repair was assessed via micro‐CT and histological staining. The nano‐carrier, stFNAs‐miR29c was successfully synthesised and exhibited exemplary biocompatibility. This nano‐nucleic acid material significantly upregulated osteogenic differentiation‐related markers in BMSCs. After 2 months, stFNAs‐miR29c demonstrated significant bone regeneration and reconstruction in CSBDs. Mechanistically, stFNAs‐miR29c enhanced osteogenesis of BMSCs by upregulating the Wnt signalling pathway, contributing to improved bone tissue regeneration. The development of this novel nucleic acid nano‐carrier, stFNAs‐miR29c, presents a potential new avenue for guided bone regeneration and bone tissue engineering research. [ABSTRACT FROM AUTHOR]

Chemical Enhanced Oil Recovery (CEOR) using polymers have recorded high sweep efficiency and favorable recovery. Polymers can be grouped into natural and synthetic polymers. The polyacrylamide (PAM) and xanthan gum (XG) are the most commonly utilized in polymer CEOR but XG is preferred for CEOR due to its tolerance to temperature, mechanical shear and salinity. XG have been utilized for field-scale CEOR studies but is very expensive to the economy of developing the countries. These exorbitant cost have driven to the search for suitable local alternatives which if successful, can improve CEOR and be exported to the global market. In this work, performance study was conducted to determine the potentials of polymer-low salinity flood to improve oil recovery. Terminalia mantaly exudate (TME) and Okra (OK) were utilized as local polymer while Xanthan gum (XG) was utilized as conventional polymers. FTIR characterization, aqueous stability, viscosity and core-flooding study were carried out in this study. From the FIIR study TME and OK recorded similar hydrophilic and hydrophobic functional group with XG, and can be categorized as polysaccharides. From Aqueous Stability study, TME, OK and XG all formed colloidal phase with water at higher temperature. From viscosity test, OK and XG recorded low viscosity tolerance in saline environment while TME recorded high viscosity tolerance in saline environment. From polymer flooding OK yielded additional 20% recovery while XG an TME recorded 17.33% and 16.89% additional recoveries respectively. In polymer-low salinity flooding, the CEOR additional crude oil recovery of OK, XG and TME increased by 11.1%, 7.7% and 7.9% respectively. The polymer-low salinity hybrid solution, recorded better recovery and this is due to synergy between the polymer an low salinity solution. [ABSTRACT FROM AUTHOR]

The combination of CRISPR/Cas12a and functional DNA provides the possibility of constructing biosensors for detecting non-nucleic-acid targets. In the current study, the duplex protospacer adjacent motif (PAM) in the activator of CRISPR/Cas12a was used as a molecular switch, and a sensitive adenosine triphosphate (ATP) detection biosensor was constructed using an allosteric probe-conjugated PAM site formation in hybridization chain reaction (HCR) integrated with the CRISPR/Cas12a system (APF-CRISPR). In the absence of ATP, an aptamer-containing probe (AP) is in a stem-loop structure, which blocks the initiation of HCR. In the presence of ATP, the structure of AP is changed upon ATP binding, resulting in the release of the HCR trigger strand and the production of long duplex DNA with many PAM sites. Since the presence of a duplex PAM site is crucial for triggering the cleavage activity of CRISPR/Cas12a, the ATP-dependent formation of the PAM site in HCR products can initiate the FQ-reporter cleavage, allowing ATP quantification by measuring the fluorescent signals. By optimizing the sequence elements and detection conditions, the aptasensor demonstrated superior detection performance. The limit of detection (LOD) of the assay was estimated to be 1.16 nM, where the standard deviation of the blank was calculated based on six repeated measurements. The dynamic range of the detection was 25–750 nM, and the whole workflow of the assay was approximately 60 min. In addition, the reliability and practicability of the aptasensor were validated by comparing it with a commercially available chemiluminescence kit for ATP detection in serum. Due to its high sensitivity, specificity, and reliable performance, the APF-CRISPR holds great potential in bioanalytical studies for ATP detection. In addition, we have provided a proof-of-principle for constructing a CRISPR/Cas12a-based aptasensor, in which the PAM is utilized to regulate Cas12a cleavage activity. [ABSTRACT FROM AUTHOR]

Lanternfishes are the most abundant species of mesopelagic fish in the ocean, playing an important role in connecting the epipelagic and mesopelagic marine food webs. Due to their global distribution, diel vertical migration, and low trophic position, they may be highly susceptible to ingest microplastics. In this study, Notoscopelus resplendens and Symbolophorus californiensis from the Northwest Pacific Ocean were used to compare and analyze potential interspecific differences in the abundance and physicochemical characteristics of microplastics in their intestines. The results showed that both lanternfish species in Northwest Pacific Ocean exhibited a high detection rate of microplastic pollution. The abundance of microplastics in the intestine of S. californiensis and N. resplendens were (0.83 ± 0.90) items/individual [(6.54 ± 8.33) items/g] and (1.17 ± 1.27) items/individual [(11.33 ± 14.06) items/g], respectively. However, no significant difference was found in abundance and size of microplastics detected in S. californiensis and N. resplendens. The shape was primarily composed of fiber (accounting for ≥80.00%). However, there were variations in the chemical composition of microplastics. Polyethylene terephthalate (PET) accounted for 36.00% and polyacrylamide (PAM) accounted for 24.00% of microplastics found in the intestines of S. californiensis, while cellophane (CP) constituted 54.29% and PET constituted 31.43% of MPs found in the intestines of N. resplendens. The microplastic pollution characteristics of lanternfish species may be influenced by accidental ingestion, nutrient transfer, and the water layers in their habitat. These findings contribute to a better understanding of the current status of microplastic pollution among lanternfish species in the same marine area, providing essential data for further exploration of the ecological effects of microplastics on mesopelagic fish in the ocean. [ABSTRACT FROM AUTHOR]

In order to solve the problem of poor stability of HPAM (partially hydrolyzed polyacrylamide) gel as a plugging agent at 150 °C, this paper investigates the preparation of a polymer gel strengthened with nano-SiO2, exhibiting good thermal stability, using a low-cost, low-hydrolysis anionic polymer. The experimental results indicated that when the gel was prepared with 1 wt% HPAM, 1 wt% water-soluble phenolic resin (WSPR) as a crosslinker, and 1 wt% nano-SiO2 as a stabilizer, the dehydration rate of the gel was less than 5 wt% after 180 days of aging at 150 °C. In order to identify the stability mechanism of nano-SiO2-strengthened polymer gel, we conducted rheological tests, Cryo-SEM analysis, Fourier transform infrared (FTIR) spectroscopy, and solid-state nuclear magnetic resonance (NMR) analysis on the polymer gel before and after adding nanoparticles. The methods described in the study demonstrate the excellent long-term thermal stability of the polymer gel strengthened with nano-SiO2 from both chemical bonding and microscopic perspectives. The results of rheological experiments indicated that the addition of nanoparticles improved the yield stress and long-term thermal stability of the gel. The scanning electron microscope (SEM) microstructure analysis confirmed that the addition of nanoparticles resulted in high-density cavities between the microscopic network structures of the gel. This facilitated the trapping of a significant amount of free water and the formation of a stable spatial mechanical support structure, ultimately enhancing the macro-mechanical strength of the gel. Additionally, FTIR and NMR experiments demonstrated that the nanoparticles effectively inhibited the hydrolysis of amide groups to carboxylate, thereby significantly preventing the high-temperature degradation of the gel and maintaining its strength after prolonged aging. [ABSTRACT FROM AUTHOR]

The effect of organic depressant DP115 (modified polyacrylamide) on the flotation of chalcopyrite and sphalerite was investigated using micro-flotation tests, and different added orders of DP115 and Z-200 were also studied. When DP115 is added first, its depression effect on sphalerite is considerable, but on chalcopyrite is weak; but when Z-200 is added first, DP115 has little depression effect on chalcopyrite flotation, whereas still strongly depresses sphalerite. The results of flotation tests on artificially mixed sample of minerals showed that for chalcopyrite-sphalerite (1:1) artificially mixed sample using Z-200 and DP115 as collector and regulator respectively, under the same flotation conditions, the selective separation index was 10.09 higher when the DP115 was added after Z-200, compared with that when the DP115 was added before Z-200. The results of the flotation separation of artificially mixed samples were in good agreement with those of single mineral flotation test, which verified the results of flotation separation of single minerals. The interaction between DP115 and Z-200 on the sulfide surface was studied by adsorption measurement. It is indicated that the Z-200 strongly absorbs on the chalcopyrite surface, and DP115 has little impact on the adsorption of Z-200 on the chalcopyrite surface, while the adsorption of Z-200 on the sphalerite surface is weak, and the competitive adsorption between DP115 and Z-200 adsorbed on the surface of sphalerite results in the desorption of Z-200 on the sphalerite surface. Time of flight secondary ion mass spectrometry (ToF-SIMS) analysis suggests that as compared to the addition first of DP115, less DP115 and more Z-200 are adsorbed on the chalcopyrite surface, while more DP115 and less Z-200 are adsorbed on the sphalerite surface, when Z-200 is added first, and so as to be more useful to realize the flotation separation of Cu-Zn. [ABSTRACT FROM AUTHOR]

Pretreated carboxymethylated nanofibrillated cellulose (CM-NFC) was tested as a strength enhancer for specialty paper, such as banknotes made from cotton linter mixed pulp (CLMP). The pretreatment agent was cationic poly(acrylamide) (C-PAM). The CM-CMF prototype was supplied by a Korean manufacturer. Laboratory tests and pilot trials were performed to evaluate the strength enhancement of banknotes incorporated with surface-modified CM-NFC and determine the process problems encountered in a pilot paper machine. The CM-NFC was surface modified with 0.1% C-PAM without any agglomerates. The prepared laboratory handsheets had high paper strength, which was attributed to the higher nanofibril content of surface-modified CM-NFC compared with that of unmodified CM-NFC. Pilot trials showed that the incorporation of 3% surface-modified CM-NFC was highly effective in promoting the strength of banknote without low retention and drainability on the wet-end part of the pilot paper machine. Therefore, surface-modified CM-NFC at a controlled dosage could be used as a strength enhancer for specialty paper without incurring serious problems in a paper mill. [ABSTRACT FROM AUTHOR]

Introduction: This study's objective was to evaluate the Auricularia auricula fungus as a coagulant of bovine milk and its potential in feta cheese production. The Auricularia auricula fungus displays high levels of milk-clotting activity, presumably due to clotting proteolytic enzymes. Methods: Feta cheese was manufactured from bovine milk, coagulated with Auricularia auricula and the proteolytic properties of the fungus were determined. Results: on polyacrylamide gel, substrates in the presence of the fungus showed higher proteolysis activity than control samples. In comparison, cheeses made with bovine rennet had more distinct protein bands than those produced with fungi. An initial evaluation of the cheese's flavor indicated a lack of bitterness and yielded positive results. Conclusion: Due to its properties and availability, the Auricularia auricula fungus might be a suitable candidate for replacing calf rennet. More research is needed to evaluate its use as a coagulant in large-scale cheese production in the future. [ABSTRACT FROM AUTHOR]

Acrylamide (AM), 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and dimethyl-diallyl ammonium chloride (DMDAAC) as monomers to prepare amphoteric polyacrylamide, the salt resistance was tested. The result showed that qualitative analysis by infrared spectroscopy and nuclear magnetic resonance confirmed that the synthesized product was the target product, and AMPAM can maintain a viscosity of more than 10 mPa ⋅ s in 20 000 mg/L NaCl solution and 10 000 mg/L CaCl2 solution. Scanning elec-tron microscopy was used to observe the changes in the microscopic morphology of AMPAM solution with 0.5% concentration at different salinity. Due to the serious weakening of intermolecular attraction and repulsion, the molecular chains began to converge and curl, forming a large number of molecular clusters and eventually forming a complete block structure. At this time, the viscosity of the solution changed little and gradually became stable. [ABSTRACT FROM AUTHOR]

In this paper, polyacrylamide (PAM) was used as the main matrix material to form the first layer network structure, and polyvinyl alcohol (PVA) was used as the secondary matrix material to form the second layer network structure. The hydrogels were prepared by free radical in‐situ polymerization and physical cross‐linking. This hydrogel was characterized not only by its semi‐interpenetrating network structure, in which cellulose nanocrystals (CNC) penetrate through the polyacrylamide network but also by the physically and chemically cross‐linked hybrid PAM/PVA double network. The structure and appearance of the hydrogels were characterized by scanning electron microscope and Fourier transform infrared spectrometer, and a series of tests were carried out to detect their mechanical properties, electrical properties and sensing properties. The results show that the hydrogel has good mechanical properties (the elongation at break can reach 600 % and the stress at break can reach 0.16 MPa), and the hydrogel also has good sensing and electrical properties. The addition of organic solvents makes the hydrogels have excellent antifreeze and water retention properties and also have excellent swelling properties. Therefore, the PAM/PVA/CNC dual network interpenetrating composite hydrogel has potential application value in the field of flexible sensors. [ABSTRACT FROM AUTHOR]

Graft modification can effectively improve the flocculation performance of chitosan. In this work, molecular dynamics simulations were employed to investigate the water solubility of chitosan-grafted polyacrylamide (CTS-g-PAM) and its adsorption mechanism with kaolinite, focusing on the effects of branched-chain length and distribution. The solubility parameters obtained from the simulations align better with those calculated using the group contribution method. The radius of gyration (Rg), solvation free energy (∆GSFE), mean square displacement and diffusion coefficient were utilized to analyze changes in solubility of these CTS-g-PAM in aqueous solution. The adsorption interaction between CTS-g-PAM and kaolinite was investigated using interaction energy and diffusion coefficients. The water solubility of CTS-g-PAM initially increased, followed by a subsequent decrease as the length of branched-chain increased along with a decrease in their number. Similarly, the adsorption interaction between CTS-g-PAM and kaolinite increased firstly followed by a decrease with increasing branched-chain length. The magnitude of interaction energy with kaolinite (0 0 1) followed the order of CA10-12 (−826.227 kcal/mol) >CA8-15 (−744.583 kcal/mol) >CA6-20 (−637.366 kcal/mol) >CA12-10 (−598.109 kcal/mol). These trends align with the findings of flocculation tests. Our work provides a theoretical basis for designing chitosan-based flocculants with enhanced water solubility and improved flocculation efficiency. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Soil Science & Plant Nutrition / Toprak Bilimi ve Bitki Besleme Dergisi is the property of Soil Science Society of Turkey and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The toughness and adhesiveness of composite hydrogels play an important role in the field of wearable sensors, where they are used due to their remarkable flexibility and diverse specialized properties. In this work, a composite hydrogel with strong toughness and high adhesion for human motion detection and wireless sensing was obtained. Polydopamine (PDA)-modified cellulose nanofibers (PCNFs) were introduced into a polyvinyl alcohol (PVA) and polyacrylamide (PAM) network, resulting in the fabrication of a PCNF/PVA-PAM composite hydrogel. Lithium chloride served as a crosslinking agent and provided conductive ions, and the PCNFs provided the composite hydrogel with strong toughness and adhesion abilities. The compression strength of the obtained PCNF/PVA-PAM composite hydrogel was 1.1 MPa, and its adhesion strength to glass was 63.8 kPa. Moreover, the composite hydrogel exhibited good anti-freezing properties. The compression sensitivity of the composite hydrogel was 1.29, and it still maintained stability even after 500 testing cycles. The strain-sensing abilities of the composite hydrogel were satisfactory for different human body parts. This composite material holds great promise in the fields of wearable devices and wireless signal transmission. [ABSTRACT FROM AUTHOR]

Odour emissions from soil remediation processes are often a cause for concerns from neighboring residents, sometimes leading to community complaints and scrutiny by the overseeing authorities. At a soil remediation site in Belgium, there are frequent reports of an odour described as "fishy" in the surroundings of the site. Upon initial site inspection, the fishy odour was not immediately evident. However, subsequent air sampling above stabilized sludge heaps revealed a high concentration of trimethylamine (TMA) as confirmed by thermal desorption gas chromatography-mass spectrometry (TD-GC-MS) analysis. TMA is associated with a pungent fishy smell and a very low odour threshold of 0.076 µg.m-3. It became apparent that the fishy smell, initially masked by the smell of wet earth, began to dominate upon dilution in the environment. Odour emissions from soil remediation processes are often a cause for concerns from neighboring residents, sometimes leading to community complaints and scrutiny by the overseeing authorities. At a soil remediation site in Belgium, there are frequent reports of an odour described as "fishy" in the surroundings of the site. Upon initial site inspection, the fishy odour was not immediately evident. However, subsequent air sampling above stabilized sludge heaps revealed a high concentration of trimethylamine (TMA) as confirmed by thermal desorption gas chromatography-mass spectrometry (TD-GC-MS) analysis. TMA is associated with a pungent fishy smell and a very low odour threshold of 0.076 µg.m-3. It became apparent that the fishy smell, initially masked by the smell of wet earth, began to dominate upon dilution in the environment. Different combinations of sludge, drying agents, and flocculants revealed that a specific polyacrylamide (PAM) based flocculant, in conjunction with the basic conditions generated by the drying agent (CaO), facilitated the production of TMA. Subsequent efforts to identify alternative combinations of drying agents and flocculants capable of mitigating TMA emissions while remaining effective for the sludge treatment were made by systematic testing. Again, the above-described small-scale screening methodology was successfully applied. This case study underscores the importance of proactive odour management strategies in soil remediation projects and the potential of the rapid screening of the applied chemicals. By understanding the underlying mechanisms of odour generation at soil remediation sites and employing mitigation measures, environmental impacts on the surroundings can be minimized. [ABSTRACT FROM AUTHOR]

Most functional hydrogels have biocompatibility problems in the pursuit of high performance, and there is an urgent need to study the problem of maintaining good biocompatibility and making hydrogels both multifunctional. Here, this paper proposes polyvinyl alcohol (PVA), chitosan quaternary ammonium salt (HACC) and polyacrylamide (PAM) with good biocompatibility as hydrogel substrates and nano-ferric copper-zinc oxide (nFCZ) as the main antimicrobial source. The physicochemical double crosslinked network hydrogels were prepared using one-pot method. Finally, the conductive properties of the hydrogel were enhanced by soaking in CaCl2 solution, and the PHP dual-network conductive antimicrobial composite hydrogel was prepared. The hydrogel was characterised, tested and analysed through various tests. The results showed that the obtained dual-network composite hydrogels had good mechanical properties, stable sensing properties, excellent swelling rate, biocompatibility and antimicrobial activity, and the bacterial inhibition rate against Escherichia coli and Staphylococcus aureus was higher than 99%. The stable electrical conductivity and sensing properties promote cell regeneration at the wound site, which broadens the scope of hydrogel applications in biomedical fields. [ABSTRACT FROM AUTHOR]

A mesoporous MFI zeolite membrane was synthesized using polyacrylamide as a secondary template to separate nickel, chromium, and nitrate ions from water. Various analytical methods were employed to characterize the zeolite powders and membranes. Subsequently, tests were conducted to evaluate water permeation and the rejection of heavy metals and nitrate ions. The incorporation of 0.03 kg kg-1 polyacrylamide resulted in a 90 % mesostructure in the MFI zeolite. Higher amounts of polymer had no positive effect on the mesoporous structure. The membrane demonstrated a high water flux (22 L m-2 h-1) with 99 % nickel and 93 % chromium rejection, and effective nitrate rejection (up to 34 %). Increasing the total dissolved solids from 1 to 1000 µA A-1 led to a 50 % increase in water flux. Additionally, raising the pressure by 2 bar resulted in an 80 % increase in the water flux and 15 % improvement in nitrate rejection. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Anatolian Environmental & Animal Science is the property of Bulent Verep and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The adoption of hydrogels in most applications is hampered by their high free water content, which limits their mechanical performance and environmental resilience. Herein, this issue is simultaneously addressed by modulating the state of water and the intermolecular interactions in polyacrylamide (PAM) hydrogels. Specifically, PAM hydrogels are toughened by sugaring‐out using a monosaccharide (glucose, G). Glucose is found to facilitate PAM hydrogen bonding and interchain interactions. Meanwhile, the high hygroscopicity of glucose converts some of the free water to bound state, endowing the hydrogels with remarkable resilience to extreme environmental conditions. The PAM‐G hydrogels are demonstrated as multimodal sensors for soft robotics. Moreover, PAM‐G alcogels produced by solvent exchanging with ethanol are shown as effective opto‐mechanical sensors. Notably, all these properties are obtained by the inclusion of glucose, a green additive showing no negative health and environmental effect. [ABSTRACT FROM AUTHOR]

Reconfiguration of architected structures has great significance for achieving new topologies and functions of engineering materials. Existing reconfigurable strategies have been reported, including approaches based on heat, mechanical instability, swelling, origami/kirigami designs, and electromagnetic actuation. However, these approaches mainly involve physical interactions between the host materials and the relevant stimuli. Herein, a novel, easy‐manipulated, and controllable reconfiguration strategy for polymer architectures is proposed by using a chemical reaction of host material within a hydrogel reactive microenvironment. 3D printed polycaprolactone (PCL) lattices transformed in an aqueous polyacrylamide (PAAm) hydrogel precursor solution, in which ultraviolet (UV) light triggered heterogeneous grafting polymerization between PCL and AAm. In situ microscopy shows that PCL beams go through volumetric expansion and cooperative buckling, resulting in transformation of PCL lattices into sinusoidal patterns. The transformation process can be tuned easily and patterned through the adjustment of the PCL beam diameter, unit cell width, and UV light on–off state. Controlling domain formation is achieved by using UV masks. This framework enables the design, fabrication, and programming of architected materials and inspires the development of novel 4D printing approaches. [ABSTRACT FROM AUTHOR]

The severe Zn‐dendrite growth and insufficient carbon‐based cathode performance are two critical issues that hinder the practical applications of flexible Zn‐ion micro‐ssupercapacitors (FZCs). Herein, a self‐adaptive electrode design concept of the synchronous improvement on both the cathode and anode is proposed to enhance the overall performance of FZCs. Polypyrrole doped with anti‐expansion graphene oxide and acrylamide (PPy/GO‐AM) on the cathode side can exhibit remarkable electrochemical performance, including decent capacitance and cycling stability, as well as exceptional mechanical properties. Meanwhile, a robust protective polymeric layer containing reduced graphene oxide and polyacrylamide is self‐assembled onto the Zn surface (rGO/PAM@Zn) at the anode side, by which the "tip effect" of Zn small protuberance can be effectively alleviated, the Zn‐ion distribution homogenized, and dendrite growth restricted. Benefiting from these advantages, the FZCs deliver an excellent specific capacitance of 125 mF cm−2 (125 F cm−3) at 1 mA cm−2, along with a maximum energy density of 44.4 µWh cm−2, and outstanding long‐term durability with 90.3% capacitance remained after 5000 cycles. This conformal electrode design strategy is believed to enlighten the practical design of high‐performance in‐plane flexible Zn‐based electrochemical energy storage devices (EESDs) by simultaneously tackling the challenges faced by Zn anodes and capacitance‐type cathodes. [ABSTRACT FROM AUTHOR]

Hydrogels, polymer networks with versatile applications in both energy-related devices and biomedicine, fall into three categories: natural, synthetic, and hybrid hydrogels. Natural variants like alginate and collagen boast biocompatibility, while synthetic counterparts, such as polyacrylamide, offer customizable properties. Hybrid hydrogels seamlessly combine the strengths of both. With their distinctive features, including high water content, flexibility, and porosity, hydrogels prove well-suited for applications in energy storage devices and biomedicine. In the energy sector, hydrogels serve as electrolytes, separators, and electrodes, enhancing battery performance and enabling the functionality of supercapacitors and fuel cells. This review initiates by exploring the pivotal role of hydrogels as energy storage devices, particularly in batteries and supercapacitors. It delves into the design principles and fabrication techniques utilized to augment the electrochemical performance, durability, and safety of hydrogel-based energy storage systems. The examination extends to various hydrogel types, such as PAMPS, PAA, and PEO hydrogels, assessing their suitability for high-performance batteries and flexible supercapacitors. Additionally, this review scrutinizes the burgeoning biomedical technologies where hydrogels play a crucial role, emphasizing their contributions to tissue engineering, drug delivery systems, biosensors, and wound healing. The unique attributes of hydrogels, including biocompatibility, adaptable mechanical properties, and controlled release capabilities, position them favorably for diverse biomedical applications. The discussion highlights notable hydrogel systems, such as alginate-based, PEGDA, and PVA hydrogels, in the context of these advancements in biomedicine. [ABSTRACT FROM AUTHOR]

Mechanically robust hydrogel fibers have demonstrated great potential in energy dissipation and shock‐absorbing applications. However, developing such materials that are recyclable, energy‐efficient, and environmentally friendly remains an enormous challenge. Herein, inspired by spider silk, a continuous and scalable method is introduced for spinning a polyacrylamide hydrogel microfiber with a hierarchical sheath‐core structure under ambient conditions. Applying pre‐stretch and twist in the as‐spun hydrogel microfibers results in a tensile strength of 525 MPa, a toughness of 385 MJ m−3, and a damping capacity of 99%, which is attributed to the reinforcement of hydrogen‐bond nanoclusters within the microfiber matrix. Moreover, it maintains both structural and mechanical stability for several days, and can be directly dissolved in water, providing a sustainable spinning dope for re‐spinning into new microfibers. This work provides a new strategy for the spinning of robust and recyclable hydrogel‐based fibrous materials. [ABSTRACT FROM AUTHOR]

To elucidate the effect of solution viscosity on the synthesis of Ni-phyllosilicate, polyacrylamide was incorporated to create a viscous aqueous medium containing of sodium metasilicate, nickel nitrate and NH 4 F. The enhanced viscosity promotes the dispersion of the initial formed crystal seeds and the growth of Ni-phyllosilicate, culminating in a Ni-rich NiPs-RT-6 of a high Ni content of up to 55.2 wt%. Residual polyacrylamide elimination was accomplished via calcination, concurrently enhancing metal-support interaction. The as-synthesized samples display a nanoflower morphology with nanospheres overlaid with numerous thin nanosheets. The relatively small Ni particles around 5.7 nm were obtained after reduction even at a very high Ni loading, owing to its strong metal-support interaction. NiPs-RT-6 achieves a CO 2 conversion of 75.9% at 450 °C, 0.1 MPa, 60 L g−1·h−1, which closely approximates thermodynamic equilibrium. The turn over frequency for CO 2 (TOF CO2) was substantial, calculated at 3.7 × 10−3 s−1, accompanied by activation energy (E a) of 80.6 kJ·mol–1. In-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) further disclosed that m -HCOO– serves as a crucial intermediate following a formate reaction pathway. With its high Ni content, finely distributed Ni particles, and strong metal-support interaction, NiPs-RT-6 demonstrates promising catalytic activity in CO 2 methanation. [Display omitted] • The room-temperature synthesis of Ni-phyllosilicate was achieved. • A viscous solvent of polyacrylamide significantly promoted the synthesis of Ni-phyllosilicate. • The reduced Ni-phyllosilicate retained small Ni particles at a high Ni content. • Polyacrylamide improved the catalytic performance of CO 2 methanation. [ABSTRACT FROM AUTHOR]

Physical changes in the tumor microenvironment, such as increased stiffness, regulate cancer hallmarks and play an essential role in gene expression, cell morphology, migration, and malignancy. However, the response of cancer cells to stiffness is not homogeneous and varies depending on the cell type and its mechanosensitivity. In this study, we investigated the differential responses of cervical (HeLa) and prostate (PC-3) cancer cell lines, as well as non-tumoral cell lines (HEK293 and HPrEC), to stiffness using polyacrylamide hydrogels mimicking normal and tumoral tissues. We analyzed cell morphology, migration, and the expression of neuropilin 1 (NRP1), a receptor involved in angiogenesis, cell migration, and extracellular matrix remodeling, known to be associated with cancer progression and poor prognosis. Our findings reveal that NRP1 expression increases on substrates mimicking the high stiffness characteristic of tumoral tissue in the non-tumoral cell lines HPrEC and HEK293. Conversely, in tumoral PC-3 cells, stiffness resembling normal prostate tissue induces an earlier and more sustained expression of NRP1. Furthermore, we observed that stiffness influences cell spreading, pseudopodia formation, and the mode of cell protrusion during migration. Soft substrates predominantly trigger bleb cell protrusion, while pseudopodia protrusions increase on substrates mimicking normal and tumor-like stiffnesses in HPrEC cells compared to PC-3 cells. Stiffer substrates also enhance the percentage of migratory cells, as well as their velocity and total displacement, in both non-tumoral and tumoral prostate cells. However, they only improve the persistence of migration in tumoral PC-3 cells. Moreover, we found that NRP1 co-localizes with actin, and its suppression impairs tumoral PC-3 spreading while decreasing pseudopodia protrusion mode. Our results suggest that the modulation of NRP1 expression by the stiffness can be a feedback loop to promote malignancy in non-tumoral and cancer cells, contingent upon the mechanosensitivity of the cells. [ABSTRACT FROM AUTHOR]

Achieving highly efficient self‐powered fibrous sensing systems is desirable for smart electronic textiles but remains a great challenge. Here, a bifunctional hydrogel is proposed by introducing of polyacrylic acid grafted MXene (MXene‐g‐PAA) into polyacrylamide/chitosan, achieving high‐sensitivity sensor and a stable hydrogel electrolyte of battery. The MXene‐g‐PAA flakes act as ion transport "highway", significantly enhance ionic conductivity, thereby increasing the sensitivity of sensors and facilitating Zn2+ diffusion in Zn‐ion battery (ZIB). The rich hydrogen bonding network in the hydrogel improves its mechanical properties and limits water molecule movement, thus reducing side reactions and prolonging the stability of ZIB. As a result, the fibrous sensor exhibits high strain sensitivity (gauge factor of 2.4) with a wide detection range (0–800%), and the fibrous Zn‐ion battery exhibits high capacity (353 mAh cm−3) with long cycling stability (400 cycles). The hydrogel‐based sensor and ZIB can be easily integrated into a flexible self‐powered sensing system, which effectively detects human movement and 3D ball motion. The bifunctional hydrogel with the integrated fibrous system will shed light on the development of next‐generation smart electronic textiles. [ABSTRACT FROM AUTHOR]

In this study, an effective and inexpensive PAA-CG composite was synthesized using polyacrylamide (PAA) and coffee ground (CG) with the help of the in situ polymerization method. The adsorption efficiency of this new composite was investigated in the removal of Pb(II) ions from an aqueous solution. Characterization was done by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy and zero charge point analysis. The maximum adsorption capacity of the PAA-CG composite was calculated as 0.622 mol/kg according to the Langmuir isotherm model. From the obtained data, it was determined that the adsorption mechanism is compatible with pseudo-second-order kinetics and intra-particle diffusion model. The calculated thermodynamic data showed that adsorption is endothermic, spontaneous and entropy increasing. [ABSTRACT FROM AUTHOR]

AbstractA composite based on polyacrylamide and Na-bentonite, designated as PAAm/Na-bentonite was prepared by in-situ radical polymerization using ammonium persulfate as an initiator and bis-acrylamide as a crosslinker. The structural and morphological features were examined by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunner − Emmet − Teller measurements. The results showed PAAm intercalation in the Na-bentonite layers. Equilibrium, thermodynamics, and kinetic studies were conducted by considering the effects of pH, initial phenol concentration, contact time and temperature. The zeta potential of the PAAm/Na-bentonite composite was calculated to understand the mechanism of phenol adsorption onto our product. The pollutant uptake behavior was determined by UV-Vis spectrophotometry. Adsorption results showed that PAAm/Na-bentonite composite showed a maximum adsorption of 160.3 mg.g−1 of 30 mg.L−1 phenol solution at pH 6 after 15 min of adsorption using 4 g.L−1 of the adsorbent. The presence of acrylamide modified the surface characteristics of the Na-bentonite and offered more adsorption sites as confirmed by XRD and SEM. Equilibrium modeling of the phenol removal process was carried out using Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich (D–R) adsorption isotherms. The equilibrium adsorption data were well fitted with the Langmuir model. In addition, the kinetics of adsorption were best described by a pseudo-second-order expression rather than a first-order model. The interactions between phenol molecules and adsorbent were explained by electrostatic as well as hydrogen bonding interactions, as confirmed by the pseudo-second-order kinetic model. A model for the interactions between the composite and the phenol molecules is proposed. The negative values of Gibb’s free energy (ΔG°) confirmed that the process was spontaneous. The positive value of change in entropy (ΔS° = 0.922 JK−1mol−1) suggests that the randomness was increased at the solution/solid interface. We suggest, the results indicate that PAAm/Na-bentonite presents a significant potential as an adsorbent material for phenol removal from aqueous solutions. [ABSTRACT FROM AUTHOR]

Carbon quantum dots (CQDs) were derived from saponin and introduced into polyacrylamide hydrogel to prepare a novel bifunctional material (CQDs@HG). This hydrogel emitted strong blue fluorescence under ultraviolet light (365 nm) and exhibited stable adsorption and detection of iron(III) in water samples. The morphological characteristics, chemical composition, Fe3+ adsorption performance, and optical properties of CQDs@HG were characterized. Depending upon the Fe3+ concentration, CQDs@HG exhibited different quenching effects to allow Fe3+ determination. The limit of detection was 0.115 μM, and the adsorption was as high as 12.13 mg/g. The mechanism was due to both static and dynamic quenching. Notably, the sensor based on CQDs@HG successfully determined Fe3+ in water samples, with spiked recoveries between 95.32% and 103.11%. When combined with software image analysis, the sensor semi-quantitatively determined Fe3+ in the field. This fluorescent hydrogel provides a reference for constructing portable sensors for monitoring hazardous substances in water. [ABSTRACT FROM AUTHOR]

Materials based on highly reactive α-tricalcium phosphate (α-TCP) powder were developed and evaluated. Furthermore, the impact of different polymeric additives, such as citrus pectin or polyacrylamide (PAAM) modified with sago starch, neem flower, or rambutan peel, on the physiochemical and biological properties of the developed materials was assessed. The addition of modified PAAM shortened the setting process of bone cements and decreased their compressive strength. On the other hand, the addition of citrus pectin significantly enhanced the mechanical strength of the material from 4.46 to 7.15 MPa. The improved mechanical properties of the bone cement containing citrus pectin were attributed to the better homogenization of cementitious pastes and pectin cross-linking by Ca2+ ions. In vitro tests performed on L929 cells showed that 10% extracts from α-TCP cements modified with pectin are more cytocompatible than control cements without any additives. Cements containing PAAM with plant-derived modifiers show some degree of cytotoxicity for the highly concentrated 10% extracts, but for diluted extracts, cytotoxicity was reduced, as shown by a resazurin reduction test and live/dead staining. All the developed bone substitutes exhibited in vitro bioactivity, making them promising candidates for further biological studies. This research underscores the advantageous properties of the obtained biomaterials and paves the way for subsequent more advanced in vitro and in vivo investigations. [ABSTRACT FROM AUTHOR]

As increasing fiber hydrophobicity can significantly improve the paper dewatering process, we found that replacing SBKP and HBKP with 0.5% superhydrophobic CPGMA can significantly improve the dewatering of paper sheets. Therefore, it can be concluded that if CPGMA has little effect on paper properties, it will have potential industrial value in the papermaking industry. Consequently, it is necessary to further study the effect of the CPGMAs@CPAM/SiO2/APAM system on paper properties. To evaluate the application potential of the system in the papermaking industry, we investigated the effects of CPGMAs, which replaced the fibers in the stocks, on the paper properties in the CPAM/SiO2/APAM system. The findings demonstrate that as the CPGMA replacement increased, the paper's tensile strength, bursting strength, tear resistance, and folding endurance all declined. The trend can be segmented into two phases: a rapid decrease for substitution amounts below 0.5% and a gradual decline for substitution amounts exceeding 0.5%. When replaced with a small amount of CPGMAs, there was a negligible effect on these properties. Second, the paper air permeability increased with the CPGMA substitution amount in the stock. Furthermore, the trend of paper air permeability can be divided into two stages—a rapid stage with a substitution amount of <0.5% and a slow stage with a substitution amount of >0.5%. A small amount of CPGMAs could distinctly improve the paper's air permeability. Third, CPGMAs, which replaced fibers in the stock, minutely affected the paper formation. A small amount of CPGMAs substantially boosted the efficacy of the process of paper manufacture and certain characteristics of the paper, and it had a negligible impact on the strength of paper. The CPGMAs@CPAM/SiO2/APAM technology has the potential to improve the retention and filtration performance of CPAM/SiO2/APAM. [ABSTRACT FROM AUTHOR]

Due to excessive phosphorus discharge in artificial ecosystems, eutrophication and the global shortage of phosphorus resources are becoming increasingly serious. Therefore, seeking for an efficient and economical phosphorus removal technology has become a pressing issue recently. In this study, sodium alginate/polyvinyl alcohol gel beads (PVA/SA) were prepared through chemical cross-linking and subsequently modified with cationic polyacrylamides (co-PAM) coating to synthesize the core–shell PVA/SA-coPAM gel beads, whose mechanical strength was improved by about 20% of PVA/SA. The influencing factors of phosphate adsorption were studied, and the reaction mechanism was explored. The scanning electron microscopy (SEM) results showed that the surface of the gel beads presented nanoscale lamellar stacking folds, and the multistage penetrating stable pore structure was formed inside. The adsorption process conformed to the pseudo-second-order kinetic equation, and the adsorption equilibrium time was 120 min. The maximum adsorption capability of PVA/SA and PVA/SA-coPAM toward phosphorus was fitted out to be 73.47 mg PO43−−P/g and 69.15 mg PO43−−P/g from the Langmuir isotherms model with pH 3, temperature 35 ℃, which was significantly higher than 30% of other adsorbents. In the acidic solution, the phosphate group was attracted to the material through electrostatic interaction. At the same time, Fe3+ and Ca2+ formed complexes with –OH and –COOH on the gel beads, and the phosphate was adsorbed to the surface of the gel beads through ligand exchange between complexes. Above all, we prepared a kind of gel beads with high strength and high phosphorus adsorption capacity for large-scale industrial applications by a simple method and economical raw materials. Also, they could be used as phosphorus fertilizer or directly used in calcination to recover phosphorus. [ABSTRACT FROM AUTHOR]

OBJECTIVE Polyacrylamide hydrogel (4% PAHG) is an inert viscoelastic supplement used to manage osteoarthritis in horses. Even with a prolonged clinical effect, horses may be administered multiple doses during their performance career. The effect of the serial 4% PAHG treatments is not known. The objectives of this study were to evaluate the clinical, histologic, and synovial fluid biomarker effects following serial administration of 4% PAHG in normal equine fetlock joints. ANIMALS 8 healthy horses. METHODS In a blinded, controlled in vivo study, horses received serial intra-articular injections of 4% PAHG (Noltrex Vet; Nucleus ProVets LLC) and contralateral 0.9% saline control on days 0, 45, 90, and 135. Treatment and control joints were randomly assigned. Synovial fluid was collected before administration of 4% PAHG or 0.9% saline on day 0 and at study completion for cellular and biomarker evaluation. Serial physical and lameness examinations were performed throughout the study. On day 240, gross examination and harvest of cartilage and synovial membrane for histology were completed. RESULTS There were no histologic changes in articular cartilage or synovial fluid biomarkers. The 4% PAHG was seen on the surface of the synovium in 5 of 8 treated joints 105 days after the last treatment. There are minimal effects following serial injections of 4% PAHG on normal joints in horses following administration at 0, 45, 90, and 135 days, with final evaluation on day 240. CLINICAL RELEVANCE Serial administration of intra-articular 4% PAHG in horses may provide long-term joint lubrication with no detrimental effects. [ABSTRACT FROM AUTHOR]

Most of the oil reserves have remained unrecovered during primary and secondary recovery scenarios which raise the need for novel and more useful recovery methods to produce the unrecovered oil and increase the recovery factor as an Enhanced oil recovery method. As the most common oil recovery method, the performance of the water injection can be further enhanced by adding polymers to water by the mobility control mechanism. Nanoparticle and nanohybrid flooding are one of those novel methods which can recover oil using wettability alteration and IFT reduction mechanisms. In this study, we synthesized polyacrylamide-based nanohybrids such as graphene oxide (GO)/PAM and carbon nanotube (CNT)/PAM combine the advantages of both nanoparticle and polymer flooding using a novel and simple method. The effect of different mechanisms involved such as wettability alteration, IFT reduction, and mobility control were studied separately in form of contact angle, IFT, and viscosity measurements and in combination with each other in the form of coreflooding tests were studied. The stability of the synthesized nanohybrids against temperature and salinity was investigated using TGA and bulk tests. The effectiveness of these novel nanohybrids was never investigated to this extent. Our investigation showed that GO/PAM nanohybrids had better performance in IFT reduction and mobility control and CNT/PAM in wettability alteration. During coreflooding tests, the GO/PAM showed the highest light and heavy oil recoveries with recovering 63.8% and 28.57%, respectively, in comparison to CNT/PAM with recovery factors of 60.95% and 25.71%. Both of the nanohybrids showed great performance in oil recovery due to wettability alteration and IFT reduction but the GO/PAM showed the best performance because of its higher viscosity which made the mobility control of the injected fluid much better. [ABSTRACT FROM AUTHOR]

Two allyldimethylalkyl quaternary ammonium salt (AQAS) monomers, N,N-dimethylallylphenylpropylammonium bromide (AQAS1) and N,N-dimethylallylnonylammonium bromide (AQAS2), were synthesized and used to prepare modified polyacrylamide materials. Two new drag reducers were synthesized from acrylamide (AM), sodium acrylate (NaAA) and a cationic modified monomer (AQAS1 or AQAS2) via aqueous solution polymerization, and the copolymers were named P(AM/NaAA/AQAS1) and P(AM/NaAA/AQAS2), respectively. The structures of the drag reduction agents were confirmed by IR and 1H NMR spectroscopies. The molecular weight (Mw) of P(AM/NaAA/AQAS1) was 1.79 × 106 g/mol. When the copolymer concentration was 1000 mg/L and the flow rate was 45 L/min, in fresh water the highest drag reduction rate was 75.8%, in 10,000 mg/L NaCl solution the drag reduction rate decreased to 72.9%. The molecular weight of P(AM/NaAA/AQAS2) was 3.17 × 106 g/mol. When the copolymer concentration was 500 mg/L and the flow rate was 45 L/min, the drag reduction rate reached 75.2%, and in 10,000 mg/L NaCl solution the drag reduction rate was 73.3%, decreased by approximately 1.9%. The drag reduction rate for partially hydrolyzed polyacrylamide (HPAM) was also investigated, and the results showed that the drag reduction rates for 500 and 1000 mg/L HPAM solutions were merely 43.2% and 49.0% in brine, respectively. Compared with HPAM, both of the above copolymers presented better drag reduction capacities. © 2024 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. [ABSTRACT FROM AUTHOR]

HPAM/PEI gel is a promising material for conformance control in hydrocarbon reservoirs. However, its use in low-permeability reservoirs is limited by the high polymer concentrations present. In this study, the gelation performance of an HPAM/PEI system with HPAM < 2.0 wt.% was systematically investigated. The gelation time for HPAM concentrations ranging from 0.4 to 2.0 wt.% varied from less than 1 h to 23 days, with the highest gel strength identified as grade H. The hydrodynamic radius manifested the primary effect of HPAM on the gelation performance. Branched PEI provided superior gelation performance over linear PEI, and the gelation performance was only affected when the molecular weight of the PEI varied significantly. The optimal number ratio of the PEI-provided imine groups and the HPAM-provided carboxylic acid functional groups was approximately 1.6:1~5:1. Regarding the reservoir conditions, the temperature had a crucial effect on the hydrodynamic radius of HPAM. Salts delayed the gelation process, and the order of ionic influence was Ca2+ > Na+ > K+. The pH controlled the crosslinking reaction, primarily due to the protonation degree of PEI and the hydrolysis degree of HPAM, and the most suitable pH was approximately 10.5. Plugging experiments based on a through-type fracture showed that multi-slug plugging could significantly improve the plugging performance of the system, being favorable for its application in fractured low-permeability reservoirs. [ABSTRACT FROM AUTHOR]