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This study focuses on enhancing cementitious materials by incorporating silanized graphene oxide (SGO) and superabsorbent polymers (SAPs), aiming to improve their mechanical and durability properties. The primary goal is to evaluate the effects of SGO/SAP composites on the hydration, absorption, shrinkage, and overall performance of concrete. The composites were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM) to understand their microstructure. Mechanical and durability tests revealed that adding SGO/SAP composites significantly increased the mechanical strength and water absorption capabilities of the concrete. The compressive strength, split tensile strength, and flexural strength of the SGO/SAP-modified concrete were measured at 57 MPa, 4.90 MPa, and 8.25 MPa, respectively. Shrinkage tests demonstrated the composite hydrogel's excellent water-holding capacity at 0.3 wt.% SGO/SAP, facilitating internal curing in concrete structures. FE-SEM analysis indicated a reduction in microcracks due to the presence of SGO/SAP. The improvements are attributed to the synergistic effects of SGO and SAP, which enhance water retention, dispersion, and interfacial bonding within the cementitious matrix. The microstructural studies confirmed the exceptional stability of the SGO/SAP-modified mix, emphasizing its potential as an additive to improve concrete properties. This research underscores the significant potential of SGO and SAP in advancing the performance of cement-based materials, highlighting their applicability in infrastructure development and construction for creating more durable and high-performing concrete structures. HIGHLIGHTS: The SGO/SAP significantly enhances the durability of cement-based materials. The SGO/SAPs exhibit superior water absorption and retention properties. Enhanced mechanical strength of SGO/SAP hydrogel-modified concrete. The durability characteristics of cement mortar improved by SGO/SAP hydrogel A decrease in the agglomeration of nanocomposite particles [ABSTRACT FROM AUTHOR]

• More than 1/3 of volume of injected polyacrylamide hydrogel (Bulkamid) disappears at 3 months follow-up. • 23 % of deposits could not be found by 3DUS at 3 months follow-up. • Only 24 % of Bulkamid injections in our patients had hypo-echoic echogenicity at 3 months follow-up. Polyacrylamide hydrogel (PAHG) is a bulking agent used in treatment of stress urinary incontinence (SUI) in women. Some women experience an improvement or cure in stress urinary incontinence (SUI) symptoms lasting only a few weeks after the injection of the bulking agent. The aim of this study was to use three-dimensional ultrasound (3DUS) to describe the changes in volume, number of deposits and echogenicity of the bulking agent 3 months after PAHG injection. Prospective cohort study of fourteen women with SUI or mixed primarily SUI, who underwent an injection of PAHG. The subjective outcome was evaluated with Patient Global Impression of Improvement questionnaire. 3DUS was performed in all patients immediately after injection of PAHG and again at 3 months follow-up. The study found a mean 36.5 % loss in bulking agent volume during the study period. A total of 53 PAHG deposits were found by ultrasound immediately after injection. At 3 months follow-up 41 PAHG deposits were left. All deposits were hypoechogenic immediately after injection and only 24 % of demonstrated PAHG collections had a hypoechoic echogenicity at 3 months follow-up. More than 1/3 of volume of injected PAHG and 23 % of deposits could not be found by 3DUS at 3 months follow-up. Only 24 % of PAHG injections in our patients had hypo-echoic echogenicity at 3 months follow-up. Larger 3DUS studies with longer follow-up and focus on exact location of the PAHG injections are important future studies. [ABSTRACT FROM AUTHOR]

Ballasted flocculation is effective for fast turbidity removal in water treatment processes. However, there is a lack of specific information for setting the conditions for ballasted flocculation. To enhance the settling velocity and removal efficiency of ballasted flocculation of actual river water, the process parameters were examined at three turbidity levels. The optimum pH and dosages for ballasted flocculation were investigated based on the relationship between the water turbidity and the floc settling velocity at the three turbidity levels. A nonionic polymer flocculant was the most suitable for floc formation and achieved the lowest turbidity and highest settling velocity. Under the optimum processing conditions at the three turbidity levels, the treated water turbidity was ˂2 turbidity units (TU) and the floc settling velocity was ˃0.7 cm/s, which was 30 times that of conventional coagulation–sedimentation, reducing the floc settling time by 97% of those used in existing water treatment plants. [ABSTRACT FROM AUTHOR]

Superabsorbent materials based on potato starch (St) grafted polyacrylamide (PAM) were synthesized by radical polymerization with ammonium persulfate as initiator. The N,N'-methylenebisacrylamide (MBA) was a crosslinking agent. Starch grafted polyacrylamides (St-g-PAM) and their hydrolyzed analogues were specified by XRay Diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry and thermal analysis. The studies confirmed the grafting of PAM into the starch backbone and partial alkaline hydrolysis of PAM. The sorption of methylene blue (MB) from aqueous solutions was investigated depending on the initial concentration of the MB solution, the contact time, the amount of PAM grafted onto starch and the structure of the sorbent (hydrolyzed or non-hydrolyzed material). In the case of non-hydrolyzed material, satisfactory sorption results (adsorption efficiency - 42 mg MB/g of sorbent and swelling mass - 1600%) were obtained for St-g-PAM with 40 wt.% of PAM (St 40PAM). On the other hand, the best results were achieved for the hydrolyzed material (H St 40PAM): 88 mg MB/g of sorbent and 2100%, respectively. [ABSTRACT FROM AUTHOR]

The effect of organic and inorganic compounds, commonly present in the mineralogy of crude oil and/or added in the washing processes of extracted crude, on the removal efficiency of emulsified oils present in waste washing waters was investigated by means of flocculation. Approximately 90% of the emulsified oil could be removed using an anionic flocculant, providing a residual turbidity below 100 NTU. The yield depended on the nature of the organic and inorganic components present. The higher the chain length of the main organic component, the greater the flocculant concentration required to remove the oil. Several components had an effect of emulsification (e.g., octane, decane), some of which rendered de‐oiling process completely ineffective (e.g., naphthenic acids). Aliphatics were the most difficult to eliminate, requiring flocculant levels in the 200–300 ppm range. This is in contrast to 75–100 ppm levels which were required to remove bi‐ and poly‐cyclic aromatics. Heavy oils were more difficult to remove than light oils. There was a strong effect of the pH of the aqueous phase. The optimum was pH = 2.0. Virtually all inorganic compounds reduced the efficiency of removing oil from water when spiked at 1%. The only exception was sodium carbonate which acted as a de‐emulsifier. Monovalent salts have a minor effect on de‐oiling, with efficiencies remaining at 80%. Divalent chlorides reduced the de‐oiling efficiency to 70% while sulphates had a more severe influence. The de‐oiling efficiency was lowered substantially with the addition of clays, zinc, cadmium, ferric oxide, calcium carbonate, and dibenyhlthiophene. [ABSTRACT FROM AUTHOR]

Brucite (Mg(OH)2) is a typical precipitate in the mining industry that adversely affects processes such as flotation and thickening. Gaining insights into the physicochemical properties of this mineral is critical for developing strategies to mitigate these challenges and improve operational efficiency. Additionally, incorporating natural-origin polymers aligns with the shift toward more sustainable mining practices. In this study, molecular dynamics simulations were employed to investigate the interaction of brucite with polysaccharides such as cellulose, guar gum, and alginate and to compare these with conventional polymers, including polyacrylamide, hydrolyzed polyacrylamide, and polyacrylic acid, under conditions of pH 11 in low-salinity water. The methodology enhanced adsorption sampling by incorporating additional temporary interactions between the polymer and the brucite surface. The results reveal that neutral polymers exhibit stronger and more stable interactions with brucite compared to charged polymers, which is consistent with the neutral nature of brucite under the studied conditions. Van der Waals forces predominantly govern the adsorption of polysaccharides, while Coulombic forces primarily drive interactions involving polyacrylamides. These findings provide valuable insights into the molecular mechanisms of polymer-brucite interactions, facilitating the development of more effective and sustainable mining additives. [ABSTRACT FROM AUTHOR]

Bio-adsorbents with high adsorption efficiency, sustainability, and reusability are desired in wastewater treatments. Herein, a covalently cross-linked green macroparticle hydrogel biocomposite (AM-AC/CMC-Ca) as a bio-adsorbent was prepared through an acrylamide (AM) reaction with a polysaccharide carboxymethyl cellulose (CMC)-modified activated carbon (AC) and further Ca(II) cross-linking polymerization, with efficient removal of Safranin T (ST) cationic dye. FESFM/EDX, XRD, FTIR, BET, and TGA were used to limit the structure and characteristics of the biocomposite. The effects of the concentration for both AM, CMC, AC, and Ca(II) cross-linked on swelling behavior were studied, which yielded that the maximum swelling ratio (SR%) in distilled water was 3500%. The ST dye adsorption capacity was evaluated, and the results illustrated that (AM-AC/CMC-Ca) biocomposite prepared under the optimized conditions displays a super strong adsorption efficiency of 1558.52 mg/g and almost 100% removal efficiency within 1 h adsorption time at pH 7.6 and 25 °C. They decrease slightly with the decrease in pH 3, and the zero-point charge was determined to be 4.2. The pseudo-first-order, pseudo-second-order, chemisorption, and intra-particle diffusion kinetic models were useful to test the experimental result, the second order exhibited the best fit for the kinetic studies. The equilibrium result was assessed using the Freundlich, Langmuir, and Fritz–Schlender isotherm model, and the Freundlich isotherm best refers to the uptake of ST dye, which suggests that the adsorption of dye in this study onto biocomposite is heterogeneous with multilayers. Thermodynamic parameters indicated that the adsorption of ST dye onto the biocomposite was spontaneous (ΔG < 0), and endothermic (ΔH > 0). Additionally, the biocomposite showed high reusability and regeneration, maintaining an 88.8% removal capacity for ST dye after 6 cycles. [ABSTRACT FROM AUTHOR]

Fair-faced concrete (FFC) with a mirror effect was successfully prepared. The grey value standard deviation, porosity, crack rate and glossiness of the concrete surface were used to characterise the apparent quality of the FFC. The effect of polycarboxylate superplasticiser (PSP) and polyacrylamide (PAM) viscosity-modifying admixture on the mirror effect of the FFC was investigated. Changes in the hydration products and microstructure of the FFC were monitored by means of X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and mercury intrusion porosity, and the potential mechanism was analysed. The results indicate that PAM reduced the number and size of calcium hydroxide (Ca(OH)2) crystals and changed the morphology of these crystals from a large-size parallel stacking state to a small-size edge eroded structure. PAM also refined the pore size of the concrete; the most probable pore size at the optimum dosage level was 13.73 nm, which was much lower than that at other PAM dosage levels. The use of PSP introduced air, which had an adverse effect on the concrete surface. However, PSP can also improve the flowability of concrete and make it easier for bubbles to discharge. The combined action of PSP and PAM provided a better mirror effect for the FFC. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office 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.)

Smart windows can effectively balance the space temperature of buildings without compromising the essential functions of windows. However, conventional thermochromic windows have limited sunlight regulation capabilities and face challenges with switching as desired. Herein, A class of novel smart windows based on crystal hydrogels is introduced that achieve free switching between transparent (for heating) and opaque (for radiative cooling) states through thermal and mechanical stimuli. The crystal hydrogels are made from cross‐linked polyacrylamide (PAM) and sodium acetate (NaAc). By optimizing the sodium acetate concentration and sample thickness, The combination of excellent cooling ability is achieved at the opaque state and good low‐temperature stability at the transparent state in the hydrogels. Using the optimized hydrogel to prepare a smart window equipped with a heater and a mechanical trigger tip, the rapid on‐demand transition between transparent and opaque states is demonstrated. The results indicate that the smart window lowers temperatures by up to 9.4 °C compared to ordinary windows and maintains stable emissivity and reflectivity even after 100 cycles due to its robust solar modulation capabilities. This technology provides new energy‐saving solutions for smart buildings but also explores future applications of smart materials, showcasing innovative advantages and technical strengths in smart windows. [ABSTRACT FROM AUTHOR]

In this study, a facile thermal condensation method was employed to prepare graphitic carbon nitride (g-C3N4) nanoparticles, and characterised by different advanced techniques. The TEM results proved that g-C3N4 had an average size of 49.7–89.3 nm. The EDX analysis of g-C3N4 confirms the existence of only C and N elements. Polyethylene oxide/polyacrylamide (PEO/PAAm) hydrogel and PEO/PAAm/g-C3N4 nanocomposite of different ratios of g-C3N4 (5, 10, and 15%) were synthesised by gamma irradiation-induced crosslinking reaction. In addition, novel magnetic (PEO/PAAm/g-C3N4/Fe3O4) nanocomposite was successfully fabricated by alkaline co-precipitation of swollen PEO/PAAm/g-C3N4 in Fe3+/Fe2+ solutions for use in the removal of Sr2+, Zn2+, and Cd2+ ions from wastewater. The PEO/PAAm/g-C3N4/Fe3O4 nanocomposite was characterised by FTIR, XRD, SEM, EDX, and VSM techniques. The XRD of PEO/PAAm/g-C3N4/Fe3O4 nanocomposite showed the presence of the typical peaks of both g-C3N4 and Fe3O4 nanoparticles. The VSM analysis indicated that the saturation magnetisation value of the nanocomposite was 18.96 emu/g, which is suitable for magnetic separation and adsorption processing. The uptake ability of PEO/PAAm/g-C3N4/Fe3O4 nanocomposite towards the Sr2+, Zn2+, and Cd2+ was examined under the effect of pH, reaction time, pH, and adsorbent dosage as well as different adsorption kinetics and isotherms models were applied. The maximum removal percentage of Cd2+, Zn2+, and Sr2+ ions was 89.8%, 97.3%, and 91.5% and achieved after 25 min at the optimum pH of 6 for Cd2+ and Zn2+, and pH 4.0 for Sr2+ ions. The fast and easy uptake of PEO/PAAm/g-C3N4/Fe3O4 nanocomposite adsorbent for the pollutants owing to the synergistic effect of existing functional groups of PEO/PAAm as well as g-C3N4 and Fe3O4 improved the removal performance of metal ions for great application in environmental remediation of wastewater treatments. [ABSTRACT FROM AUTHOR]

Summary Recent observational and experimental trials have demonstrated that intra‐articular 2.5% injectable polyacrylamide hydrogel (2.5 iPAAG) is highly effective, lasting and safe for the treatment of equine osteoarthritis (OA). Over the last decade, intra‐articular 2.5 iPAAG has shown to be a potent and promising drug in the medication of OA in horses, as no other single medical treatment for OA has such prolonged efficacy. Preliminary observations on the mechanisms of action of intra‐articular 2.5 iPAAG support a mechanical effect through integration into the synovial membrane, an increase in joint elasticity possibly reducing overall joint capsule stiffness, and provision of lasting viscosupplementation which contributes to protecting articular surfaces. Because 2.5 iPAAG is an inert and biocompatible hydrogel, no effects on arthrocentesis cytology parameters have been observed. Studies also suggest that the positive effects of 2.5 iPAAG occur in the absence of intra‐articular neurotoxicity or fibrosis, with a low‐level macrophage‐driven foreign body response. The effect on the synovial membrane and joint capsule and the long‐acting viscosupplementation represent new concepts in the management of equine OA. [ABSTRACT FROM AUTHOR]

The intricate muscle arrangement structure endows the biological tissues with unique mechanical properties. Inspired by that, a mechanically robust and multifunctional anisotropic Polyacrylamide/Sodium alginate/Zirconium ion/Carbon dots (PAM/SA/Zr4+/CDs, PSZC) hydrogel is developed through the synergistic effect of mechanical‐assisted stretching, Zr4+ metal‐coordination and CDs embedding. The resulting hydrogel exhibited an impressive tensile strength of 2.56 MPa and exceptional toughness of 10.10 MJ m−3 along the stretching direction, attributing to the oriented alignment of PAM and SA molecular chains induced by mechanical‐assisted stretching and metal‐coordination. The dense network structure endowed the PSZC hydrogel with excellent anti‐swelling performance, achieving a swelling ratio of only 1.7% after being stored in water for 30 days. The presence of Zr4+ conferred remarkable electrical conductivity of 2.15 S m−1 to the PSZC hydrogel. Furthermore, the integration of carbon dots imparted the PSZC hydrogel fluorescence properties, rendering it visual sensing capabilities. Overall, a straightforward strategy is proposed for fabricating a mechanically robust and multifunctional hydrogel suitable for underwater sensing and visual sensing, offering valuable insights for the development of high‐performance underwater sensors. [ABSTRACT FROM AUTHOR]

Copyright of Oilfield Chemistry is the property of Sichuan University, Oilfield Chemistry Editorial Office 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.)

Copyright of Oilfield Chemistry is the property of Sichuan University, Oilfield Chemistry Editorial Office 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.)

Water scarcity is a global issue. Solar-driven adsorption-based atmospheric water harvesting (SWAH) is an effective method to address the problem of freshwater shortage. However, the low water absorption capacity of adsorbents and the inability to utilize natural sunlight for desorption and regeneration hinder efficient atmospheric water harvesting. In this study, a high-performance composite hydrogel adsorbent, PAM–CMCNa–GO@CaCl2, was prepared by free radical-initiated polymerization and impregnation method. By incorporating graphene oxide (GO) into the polyacrylamide–carboxymethyl cellulose sodium (PAM–CMCNa) copolymer hydrogel matrix, a PAM–CMCNa–GO hydrogel is synthesized, which endows the hydrogel with excellent photothermal conversion performance. This allows the hydrogel to undergo desorption and regeneration driven by natural sunlight. By confining hygroscopic calcium chloride (CaCl2) within the PAM–CMCNa–GO hydrogel matrix, the high moisture absorption capacity of calcium chloride (CaCl2) and the swelling ability of the hydrogel are utilized to capture and store water vapor from the air. Furthermore, through the synergistic use of a low-concentration salt solution strategy and hydrogel swelling strategy to prevent salt solution leakage, efficient atmospheric water harvesting is achieved. The prepared composite adsorbent, PAM–CMCNa–GO@CaCl2, achieves a water vapor capture rate of 0.307–2.596 g g−1 within a wide humidity range (30–90% RH), without salt solution leakage under the environmental conditions of 25 °C and 90% RH. Indoor water harvesting experiments demonstrate that the PAM–CMCNa–GO@CaCl2 composite adsorbent can collect 122% of its own weight of liquid water through 12 hours of adsorption (25 °C, 90% RH) and 6 hours of desorption (1 kW m−2) under sunlight. [ABSTRACT FROM AUTHOR]

Featured Application: Poly(acrylic acid)/poly(acrylamide) microgels with an IPN structure demonstrate smart behavior with dual pH and temperature responsiveness. Both factors are determinative for human physiology. This, combined with the anionic nature of these microgels, determines their potential as a suitable carrier for the drug delivery of cationic drugs through the gastro-intestinal tract. Microgels with precisely tuned properties are of great importance as drug delivery systems. Here, we report the synthesis of microgel particles (MGs) with an interpenetrating polymer network structure composed of poly(acrylic acid) (PAA) and polyacrylamide (PAAM) for their potential application as cationic drug carriers. The MG properties were investigated via several analytical techniques, such as Dynamic Light Scattering (DLS) and zeta potential (ZP) measurements, Diffusion Nuclear Magnetic Resonance (NMR) spectroscopy, Asymmetrical Flow Field-Flow Fractionation (AF4) and Transmission Electron Microscopy (TEM). The MGs show pH-dependent swelling behavior with a radius of ~100 nm at collapsed state (pH < 4.5) and swell up to ~450 nm (pH~7), while their ZP decreases from −5 to −40 mV, depending on their composition. The results of the conducted studies demonstrate the potential of synthesized microgels for drug delivery in the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

Cell shape and function are intimately linked, in a way that is mediated by the forces exerted between cells and their environment. The relationship between cell shape and forces has been extensively studied for cells seeded on flat 2D substrates, but not for cells in more physiological 3D settings. Here, a technique called 3D micropatterned traction force microscopy (3D‐µTFM) to confine cells in 3D wells of defined shape, while simultaneously measuring the forces transmitted between cells and their microenvironment is demonstrated. This technique is based on the 3D micropatterning of polyacrylamide wells and on the calculation of 3D traction force from their deformation. With 3D‐µTFM, it is shown that MCF10A breast epithelial cells exert defined, reproducible patterns of forces on their microenvironment, which can be both contractile and extensile. Cells switch from a global contractile to extensile behavior as their volume is reduced are further shown. The technique enables the quantitative study of cell mechanobiology with full access to 3D cellular forces while having accurate control over cell morphology and the mechanical conditions of the microenvironment. [ABSTRACT FROM AUTHOR]

This study presents an in vivo optical hydrogel microneedle platform that measures levels of analytes in interstitial fluid. The platform builds on a previously published technique for molding hydrogel microneedles by developing a composite hydrogel (i.e., PEGDA and polyacrylamide) that is sufficiently stiff to penetrate skin in the hydrated state and whose fluorescence changes dynamically–via a conjugated aptamer–depending on level of analyte. In a demonstration relevant to hypercalcemia, the hydrogel microneedle distinguished varying concentrations of calcium (within a range of 0 to 2 mM, which spans physiologically meaningful variations for hypoparathyroidism) within 10 minutes. In rats, a compact CMOS sensor measuring fluorescence from microneedles distinguished low hypercalcemic (1.7 mM) from high hypercalcemic (2.3 mM) ionized calcium levels as determined from reference blood measurements. Overall, this work demonstrates in vivo feasibility of a concept–which we call mPatch–for an optical hydrogel microneedle to measure small changes in levels of analytes in interstitial fluid, which does not rely on extraction of interstitial fluid out of the dermis. [ABSTRACT FROM AUTHOR]

Passive cooling technologies being free from additional energy consumption, offer significant advantages in reducing carbon emissions and mitigating global warming. However, radiative cooling has a thermodynamic limit, and evaporative cooling requires additional components, which restricts their large‐scale application, respectively. Herein, a radiative/evaporative bifunctional cooling bilayer is presented, featuring an upper layer composed of poly(vinylidene fluoride‐cohexafluoropropene) [P(VdF‐HFP)] integrated with a hygroscopic hydrogel lower layer [polyacrylamide (PAAm)/alginate‐CaCl2]. High solar reflectance (0.916) and long‐wave infrared emittance (0.900) of the P(VdF‐HFP) combined with hydrogel evaporation enable a notable 15.4 °C temperature drop under 706.3 W·m−2 solar radiation. The bilayer is demonstrated to be effective under outdoor conditions for continuous three cloudy days, achieving an average temperature reduction ranging from 6.3 to 15.7 °C. Considering the low cost and simplicity of the preparation method, ease of large‐scale fabrication, and good cooling performance, this bilayer structure provides a promising strategy for the application of passive cooling. [ABSTRACT FROM AUTHOR]

Polyacrylamide (PAAm) hydrogels are widely adopted as 2D‐model soft substrates for investigating cell‐material interactions in a controlled in vitro environment. They offer facile synthesis, tunable physico‐chemical properties, diverse biofunctionalization routes, optical transparency, mouldability in a range of geometries and shapes, and compatibility with living cells. PAAm hydrogels can be engineered to reconstruct physiologically relevant biointerfaces, like cell‐matrix or cell–cell interfaces, featuring biochemical, mechanical, and topographical cues present in the extracellular environment. This Review provides a materials science perspective on PAAm material properties, fabrication, and modification strategies relevant to cell studies, highlighting their versatility and potential to address a wide range of biological questions. Current routes are presented to integrate cell‐instructive features, such as 2D patterns, 2.5D surface topographies, or mechanical stiffness gradients. Finally, the recent advances are emphasized toward dynamic PAAm hydrogels with on‐demand control over hydrogel properties as well as electrically conductive PAAm hydrogels for bioelectronics. [ABSTRACT FROM AUTHOR]

In mineral processing operations, it is essential to effectively remove the fine particles in slime and tailings slurry with appropriate methods. In this study, a unique two-stage flocculation scheme was developed for achieving effective separation of fine kaolinite particles from water by polyacrylamide. The slurry turbidity and flocculation kinetic parameters were used to characterize the effect of the dosing ratio between the first and second stage on the kaolinite flocculation behavior and settling rate. The results showed that the maximum kaolinite settling rate and the minimum turbidity of slurry supernatant was achieved when 60% and 40% polyacrylamide was added in the first and second stage, respectively. Focused beam reflectometer (FBRM) and particle video microscope (PVM) results showed that the flocs formed in the first stage of dosing were large in size but small in fractal dimension and no significant sedimentation was observed. The second stage of dosing produced large size of flocs with large fractal dimension, which settled fast in slurry. Fourier transform infrared spectroscopy (FTIR) results showed that polyacrylamide was mainly adsorbed on the surface of kaolinite by hydrogen bonding and kaolinite particle flocculation was achieved by trapping and coiling of the polymer chain structure. The two-stage dosing process accomplished effective flocculation and rapid settlement of fine kaolinite particles. The findings from this study provide a feasible approach for mining companies to optimize the flocculation and sedimentation of fine particles. [ABSTRACT FROM AUTHOR]

Direct discharge of Congo red (CR) dye wastewater can cause environmental pollution. Herein, magnetic polyacrylamide/sodium alginate/Fe3O4@ZIF-8 (PAM/SA/Fe3O4@ZIF-8) hydrogel beads with semi-interpenetrating polymer network (SIPN) structure were prepared by combining the properties of PAM/SA hydrogel and Fe3O4@ZIF-8 for removal of CR. The magnetic hydrogel beads were characterized by SEM, EDS, FTIR, XRD, and BET. The effect of different factors on the adsorption of CR by magnetic hydrogel beads was investigated. The results showed that the addition of Fe3O4@ZIF-8 improved the adsorption capacity of PAM/SA hydrogel beads and the maximum adsorption amount of CR by magnetic PAM/SA/Fe3O4@ZIF-8-8 was 234.69 mg g−1. The adsorption of CR on PAM/SA/Fe3O4@ZIF-8-8 complied with the Pseudo-second-order kinetic model and Freundlich model. Thermodynamic analyses indicated that the adsorption process was endothermic and spontaneous. The adsorption mechanism of PAM/SA/Fe3O4@ZIF-8 on CR was based on electrostatic attraction, metal coordination, hydrogen bonding, and π-π stacking. PAM/SA/Fe3O4@ZIF-8-8 had excellent selective adsorption and cyclic regeneration performance for CR removal. This study showed that magnetic PAM/SA/Fe3O4@ZIF-8 hydrogel beads can be used as a new effective adsorbent for the recovery of CR in wastewater. [ABSTRACT FROM AUTHOR]

The bone marrow (BM) niches are the complex microenvironments that surround cells, providing various external stimuli to regulate a range of haematopoietic stem cell (HSC) behaviours. Recently, it has been proposed that the fate decision of HSCs is often correlated with significantly altered biophysical signals of BM niches. To thoroughly elucidate the effect of mechanical microenvironments on cell fates, we constructed 2D and 3D cell culture hydrogels using polyacrylamide to replicate the mechanical properties of heterogeneous sub‐niches, including the inherent rigidity of marrow adipose tissue (2 kPa), perivascular tissue (8 kPa) and endosteum region (35 kPa) in BM. Our observations suggest that HSCs can respond to the mechanical heterogeneity of the BM microenvironment, exhibiting diversity in cell mechanics, haematopoietic pool maintenance and differentiated lineages. Hydrogels with higher stiffness promote the preservation of long‐term repopulating HSCs (LT‐HSCs), while those with lower stiffness support multi‐potent progenitors (MPPs) viability in vitro. Furthermore, we established a comprehensive transcriptional profile of haematopoietic subpopulations to reflect the multipotency of haematopoietic stem and progenitor cells (HSPCs) that are modulated by niche‐like stiffness. Our findings demonstrate that HSPCs exhibit completely distinct downstream differentiated preferences within hydrogel systems of varying stiffness. This highlights the crucial role of tissue‐specific mechanical properties in HSC lineage decisions, which may provide innovative solutions to clinical challenges. [ABSTRACT FROM AUTHOR]

Robust and biocompatible hydrogels are recognized as promising biomimetic soft materials to improve human life quality. To ensure their stable, reliable, and safe service, the hydrogels are further required to have non‐contact and wireless stress sensing ability. Herein, a mechanoluminescence (ML) based micellar hydrogel is developed, in which the surface‐modified BaSi2O2N2: Eu2+ (M‐BSON) particles are chemically incorporated into the cross‐linked polyacrylamide/polymethyl acrylate (PAM/PMA) network structure. Because of the interactions between the M‐BSON particles and the PMA micelles, the as‐fabricated composite hydrogel exhibits enhanced mechanical properties with a mechanical strength of 2.73 MPa and a toughness of 3.40 MJ m−3, respectively. The chemical wrapping of the M‐BSON particles by the hydrophobic PMA micelles further protects the ML properties from water quenching, leading to remarkable stress‐induced luminescence under the water environment of hydrogel. Because of its desirable mechanical performance, attractive stress‐light responsiveness, and good biocompatibility, the M‐BSON incorporated hydrogel has the potential to be applied as an intelligent artificial ligament for stress self‐monitoring and failure warning. This work addresses the inhomogeneous dispersion and water quenching issues of the ML particles in hydrogel structure, which significantly promote ML applications in bionic engineering. [ABSTRACT FROM AUTHOR]

In this study, a thermoresponsive double‐network (DN) nanocomposite hydrogel is developed. The primary hydrogel network comprises Pluronic P123, while the secondary network comprises gelatinmethacrylate (GELMA) and polyacrylamide (PAM). A systematic approach is adopted to develop DN hydrogels. Initially, the impact of Pluronic P123 concentrationon the mechanical properties of PAM‐GELMA hydrogel is investigated. Results from the tensile strength and the oscillatory shear tests reveal that an increasing P123 concentration has a marginal effect on the storage modulus while significantly reducing the loss modulus of the PAM‐GELMA hydrogel, thereby improving mechanical properties. Notably, DN3 hydrogel containing 7.5w/v% P123 in PAM‐GELMA exhibits osteoid matrix‐like mechanical properties. To further enhance the mechanical properties, citrate‐containing amorphous calcium phosphate (ACP_CIT) is incorporated in DN3 hydrogel at varying concentrations. At a lower concentration of ACP_CIT (0.75 w/v%), the mechanical properties of DN3‐ACP0.75 hydrogel are notably enhanced. Incorporating ACP_CIT in DN3 hydrogel (DN3‐ACP0.75) decreases creep strain, rapid stress relaxation, and reduced water uptake capacity while maintaining the thermoresponsive behavior. Finally, an in vitro analysis confirms the cytocompatibility of the hydrogels with MC3T3‐E1 cells, indicating the potential use in bone tissue engineering. [ABSTRACT FROM AUTHOR]

Copyright of Wool Textile Journal is the property of National Wool Textile Science & Technology Information Center 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.)