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The COVID-19 pandemic required great efforts to develop efficient vaccines in a short period of time. However, innovative vaccines against SARS-CoV-2 virus are needed to achieve broad immune protection against variants of concern. Polymeric-based particles can lead to innovative vaccines, serving as stable, safe and immunostimulatory antigen delivery systems. In this work, polymeric-based particles called thiolated PAA/Schizo were developed. Poly (acrylic acid) (PAA) was thiolated with cysteine ethyl ester and crosslinked with a Schizochytrium sp. cell wall fraction under an inverse emulsion approach. Particles showed a hydrodynamic diameter of 313 ± 38 nm and negative Zeta potential. FT-IR spectra indicated the presence of coconut oil in thiolated PAA/Schizo particles, which, along with the microalgae, could contribute to their biocompatibility and bioactive properties. TGA analysis suggested strong interactions between the thiolated PAA/Schizo components. In vitro assessment revealed that thiolated particles have a higher mucoadhesiveness when compared with non-thiolated particles. Cell-based assays revealed that thiolated particles are not cytotoxic and, importantly, increase TNF-α secretion in murine dendritic cells. Moreover, immunization assays revealed that thiolated PAA/Schizo particles induced a humoral response with a more balanced IgG2a/IgG1 ratio. Therefore, thiolated PAA/Schizo particles are deemed a promising delivery system whose evaluation in vaccine prototypes is guaranteed. [ABSTRACT FROM AUTHOR]

Silicon (Si) -based materials have been identified as a potential alternative anode owing to their superior theoretical capacity compared to conventional graphitic carbon. Nevertheless, the huge volume change (approximately 300%) that occurs while cycling still hampers this system from 100% practical applications. Silicon-monoxide (SiOx)-based anode materials, on the other hand, are being explored extensively due to their unique properties such as high theoretical capacity, formation of Li2O and LiSiO4 during initial lithiation process that act as a natural volume buffer matrix to accommodate volume changes and formation of a stable solid electrolyte interphase layer, which improves the cyclability and capacity retention. Although poly (vinylidene fluoride) (PVdF) is widely used as a binder, the weak van der Waals forces between PVdF and silicon-based particles fail to bind particles effectively, when substantial volume change occurs. Herein, we prepare a series of SiOx-Si-C electrodes with different binders poly (acrylic acid) (PAA), carboxyl methyl cellulose (CMC) and their blends as binder. The prepared polymeric blends are subjected to thermal, morphological, mechanical and physico-chemical analyses. The Li/ SiOx-Si-C cell assembled with 100% PAA as binder delivered a discharge capacity of 1908 mAh g−1 on its first cycle and 724 mAh g−1 on its 100th cycle with a fade in capacity of 11.8 mAh g−1 per cycle. Upon the incorporation of CMC in the PAA blend the cycling performance was found to be poor. Among the various investigated compositions, the electrode with sole poly (acrylic acid) as a binder offers the highest discharge capacity and this is attributed to the high concentration of the functional (carboxylic) group which forms strong hydrogen bonds with - OH groups on the SiOx or carbon surface. The interfacial properties of the polymeric binders are thoroughly investigated by spectroscopies and electrochemical tests. [ABSTRACT FROM AUTHOR]

The quest for sustainable and functional food packaging materials has led researchers to explore biopolymers such as pullulan, which has emerged as a notable candidate for its excellent film-forming and anti-fogging properties. This study introduces an innovative anti-fog coating by combining pullulan with poly (acrylic acid sodium salt) to enhance the display of packaged food in high humidity environments without impairing the sealing performance of the packaging material—two critical factors in preserving food quality and consumers' acceptance. The research focused on varying the ratios of pullulan to poly (acrylic acid sodium salt) and investigating the performance of this formulation as an anti-fog coating on bioriented polypropylene (BOPP). Contact angle analysis showed a significant improvement in BOPP wettability after coating deposition, with water contact angle values ranging from ~60° to ~17° for formulations consisting only of poly (acrylic acid sodium salt) (P0) or pullulan (P100), respectively. Furthermore, seal strength evaluations demonstrated acceptable performance, with the optimal formulation (P50) achieving the highest sealing force (~2.7 N/2.5 cm) at higher temperatures (130 °C). These results highlight the exceptional potential of a pullulan-based coating as an alternative to conventional packaging materials, significantly enhancing anti-fogging performance. [ABSTRACT FROM AUTHOR]

Soil salinity, a severe environmental factor, significantly reduces the productivity of crop plants by increasing salt and mineral fertilizer concentrations in the soil. As a result, the development of sustainable slow-release mineral fertilizers (SRFs) is critical for addressing salt-affected soils. This study aimed to synthesize struvite (MgNH4PO4·6H2O) into hydrogel beads made from sodium alginate-poly (acrylic acid) in the absence (Sa@S) and presence (Sa@SHa) of humic acid (HA). The optimal conditions for struvite formation were at pH 9.0, resulting in a remarkable 73.21 %, 98.74 %, and 99.20 % for Mg, NH4-N and P removal, respectively. The SRFs study demonstrated that struvite had a significant release of Mg, P, and NH4-N, notably higher (P ≤ 0.05) than Sa@S and Sa@SHa. Experiments on swelling and soil water loss demonstrated that Sa@S yielded higher results in comparison to Sa@SHa. Furthermore, an experiment was conducted to study the impact of Sa@S and Sa@SHa on saline soil parameters over 20 days of incubation. The results showed both encapsulated struvite hydrogel beads reduced soil salinity, as indicated by the sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP). Additionally, a significant reduction (P ≤ 0.05) in soil electrical conductivity (EC) and sodium (Na) was observed for both hydrogel bead encapsulation treatments compared to the control soil. However, no apparent variance was observed in pH and soil organic carbon (SOC). Moreover, the levels of available phosphorus (P), ammonium-nitrogen (NH4-N), nitrate-nitrogen (NO3-N), cation exchange capacity (CEC), and exchangeable cations (Ca, Mg, K) in the soil were observed to be increased (P ≤ 0.05).

Poly (acrylic acid) (PAA), an anionic polymer was used to prepare ion pair self-assembly (IPSAM) with 4-(methylthio)aniline (MTA), a hydrophobic counter ion, which is responsive to temperature and oxidation. The IPSAM was formed when the carboxylic to amino group molar ratio was 7/3-5/5. The structure of the IPSAM nanoparticle was spherical whose diameter was 30-40 nm on the TEM images. The PAA/MTA ion pair showed the upper critical solution temperature (UCST) that hiked with increasing MTA content. When the MTA of the ion pair was oxidized by H2O2, the UCST was also increased. The amphiphilic property of the ion pair was responsible for interface activity which declined upon the oxidation of the MTA. The surface tension was low for the ratio of PAA/MTA (5/5), which made the 5/5 ratio suitable for further studies. The interaction between PAA and MTA, which was ionic, and the oxidation of MTA was confirmed by FT-IR spectroscopy. The release of payload (i.e. Nile red) in IPSAM was restrained below the UCST but it was triggered above the phase transition temperature possibly due to the disintegration of the IPSAM whereas on MTA oxidation the release was shielded due to more hydrophobicity. The release was found to be higher in tumor environment temperature which could be controlled with the input concentration of H2O2 giving a stable IPSAM. The cell viability results showed that IPSAM has no significant cytotoxicity and can serve as a drug carrier for stimulus-response. [ABSTRACT FROM AUTHOR]

Hydrogel beads, composed of polymers, possess the ability to absorb substantial quantities of water simultaneously and gradually release it in dry conditions. In this work, hydrogel beads were synthesized using sodium alginate (S-Alg) and poly (acrylic acid) (P-Acc), either in the absence or presence of phosphate (PO43−) (S-Alg/P-Acc@PO43−) and carbonate (CO32−) anionic ions (S-Alg/P-Acc@CO32−). Subsequently, these beads were crosslinked with Ca2+ ions. The scanning electron microscopy (SEM) images demonstrated that the presence of anionic ions has an impact on the structure of the hydrogel beads and enhances porosity expansion while concurrently reducing the concentration of carboxyl (COOH) groups. The hydrogel beads exhibited a great swelling behavior, with S-Alg/P-Acc@CO32− capable of absorbing up to 73.5 % of water in acidic conditions, but decreased under neutral and basic conditions. Soil water loss (SWL) experiments confirmed the ability of hydrogel beads to retain water in the soil. Additionally, observations of soil characteristics after a 14-day treatment revealed no significant difference in pH and C/N ratio (P-value

The COVID-19 pandemic required great efforts to develop efficient vaccines in a short period of time. However, innovative vaccines against SARS-CoV-2 virus are needed to achieve broad immune protection against variants of concern. Polymeric-based particles can lead to innovative vaccines, serving as stable, safe and immunostimulatory antigen delivery systems. In this work, polymeric-based particles called thiolated PAA/Schizo were developed. Poly (acrylic acid) (PAA) was thiolated with cysteine ethyl ester and crosslinked with a Schizochytrium sp. cell wall fraction under an inverse emulsion approach. Particles showed a hydrodynamic diameter of 313 ± 38 nm and negative Zeta potential. FT-IR spectra indicated the presence of coconut oil in thiolated PAA/Schizo particles, which, along with the microalgae, could contribute to their biocompatibility and bioactive properties. TGA analysis suggested strong interactions between the thiolated PAA/Schizo components. In vitro assessment revealed that thiolated particles have a higher mucoadhesiveness when compared with non-thiolated particles. Cell-based assays revealed that thiolated particles are not cytotoxic and, importantly, increase TNF-α secretion in murine dendritic cells. Moreover, immunization assays revealed that thiolated PAA/Schizo particles induced a humoral response with a more balanced IgG2a/IgG1 ratio. Therefore, thiolated PAA/Schizo particles are deemed a promising delivery system whose evaluation in vaccine prototypes is guaranteed.

Tenofovir (TNF), a nucleotide analogue of adenosine 5′-monophosphate, is the first-line treatment for chronic HIV/hepatitis B coinfection. There is a need to explore highly sensitive, rapid, and cost-effective quality control techniques to detect the drug. Nickel sulphide @ poly(acrylic acid) coated multi-walled carbon nanotubes (NiS@PAA-MWCNT) composite was synthesized using the one-step solvothermal method. The composite was characterized by UV-vis spectroscopy, Fourier transforms infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. Morphological analysis showed polydispersed NiS on the surface of the poly(acrylic acid) coated multi-walled carbon nanotube (MWCNT). Tenofovir was electrochemically detected in human urine by differential pulse voltammetry (DPV) using the NiS@PAA-MWCNT modified glassy carbon electrode. The linear range was found to be from 20 to 80 µM with a limit of detection of 5.83 × 10−12 M and 5.12 × 10−12 M in phosphate buffer and human urine, respectively. The practical applicability of the modified electrode was evaluated in human urine and in the presence of different interfering agents. The electrode demonstrated good reproducibility, selectivity, and sensitivity. Thus, NiS@PAA-MWCNT nanocomposite can be used in electrochemical sensors for quality control purposes. [ABSTRACT FROM AUTHOR]

In this study, nanofibers of poly (acrylic acid) (PAAc), polyacrylamide (PAAm) and poly (vinyl alcohol) (PVOH) were prepared using the electrospinning technique. Based on the Taguchi DOE (design of experiment) method, the effects of electrospinning parameters, i.e., needle tip to collector distance, polymer solution concentration, applied voltage, polymer solution feed rate and polymer type, on the diameter and morphology of polymer nanofibers were evaluated. Analyses of the experiments for the diameters of the polymer nanofibers showed that the type of polymer was the most significant factor. The optimal combination to obtain the smallest diameters with minimum deviations for electrospun polymer nanofibers was also determined. For this purpose, the appropriate factor levels were determined as follows: polymer PAAm, applied voltage 10 kV, delivery rate 0.1 mL/h, needle tip to collector distance 10 cm, and polymer solution concentration 8%, to obtain the thinnest nanofibers. This combination was further validated by conducting a confirmation experiment, and the average diameter of the polymer nanofibers was found to be close to the optimal conditions estimated by the Taguchi DOE method. [ABSTRACT FROM AUTHOR]

Herein, poly (acrylic acid) (PAA) microgels were synthesized via alcohol type cross-linked by a free radical precipitation polymerization approach. At the first time, 1,6-hexanediol (1–6 diol), trimethylolpropane (TMP), and pentaerythritol (PEN) were selected as multifunctional cross- linking agent to synthesize cross-linked poly(acrylic acid) microgels. Alcohol type cross-linking agents can connect the PAA chains. The cross-linking reaction takes place due to reaction between hydroxyl groups of various cross-linkers and carboxyl groups of PAA chains. All of the hydroxyl groups do not participate in the reaction with acid groups of polymer chains through the polymerization stage; therefore, unreacted hydroxyl groups will react through sample drying (post-curing stage). The influence of cross-linker functionality and its concentration on various properties like swelling capacity, gel content, Tg (glass transition temperature), and rheological behavior were examined. The PAA microgels prepared via this cross-linking approach were compared to properties of microgels synthesized by epoxy type and vinyl type cross-linking agents in the previous studies. As a result, synthesized microgels via novel mechanisms have higher properties (for example, rheological and thermal properties) than that of PAA microgels prepared via the conventional mechanism. These behaviors can be due to decreasing Mc ¯ (average molecular weight of two successive cross-links) in the polymeric network by utilizing new cross-linkers. [ABSTRACT FROM AUTHOR]

Poly (acrylic acid) (PAA) nanocomposite hydrogel was fabricated as a sensing patch for non-invasive dual detection of urea in sweat. The hydrogel was prepared by γ-irradiation crosslinking of PAA solution incorporated with graphene oxide (GO) and cellulose nanofiber (CNF). With high water-sorption capacity and transparency, the hydrogel was suitable to accommodate coloring reagents and enzymes for colorimetric sensing of urea in sweat. The colorimetric sensor exhibited vivid color change towards the increase of urea concentration in a linear range of 40–80 mM covering a cut-off value (60 mM) for chronic kidney disease (CKD) indication. Furthermore, the hydrogel could be directly applied as a substrate for direct quantitation of urea in sweat by laser desorption ionization mass spectroscopy (LDI-MS). While CNF improved the mechanical properties of the hydrogel, GO played a key role in enhancing laser desorption ionization of urea in LDI-MS and increased the hydrogel functionalities. LDI-MS verified that GO/CNF/PAA hydrogel could act as a direct matrix for promoting urea ionization and these results corresponded well with the colorimetric sensor. Hence, this hydrogel patch might be a potential material to be applied in non-invasive and dual-detection of CKD in medical diagnosis. [Display omitted] • GO/CNF/PAA hydrogel was prepared by γ-irradiation crosslinking. • The hydrogel possesses high swelling capacity and high flexibility. • The hydrogel was applied for non-invasive detection of urea in sweat. • The hydrogel was used for colorimetric screening of urea in sweat. • The hydrogel patch was used as a substrate for LDI-MS quantitation of urea. [ABSTRACT FROM AUTHOR]

Polymer-based catalysts have never been used before as anode catalysts in direct formic acid fuel cells. At present, Poly (acrylic acid), Poly (AA) was prepared and electrodes were constructed on graphite pencil (G) from these hydrogels. Furthermore, Pd doped Poly (AA)/G electrodes were prepared by employing electrodeposition techniques, and their formic acid electrooxidation (FAEO) activities were examined via cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. These electrodes were characterized by DTTGA, FTIR, and SEM-EDX. It was observed that Poly (AA)/G were prepared successfully. Poly (AA)/G electrode exhibited promising electrocatalytic activity as a DFAFC anode catalyst. By the modification with Pd, the FAEO activity increased for Poly (AA)/G with 38 mA/cm2 current density, greater than literature values. In conclusion, it is clear that these Pd doped Poly (AA)/G electrodes have superior activity towards formic acid electrooxidation. [ABSTRACT FROM AUTHOR]

Soil salinity, a severe environmental factor, significantly reduces the productivity of crop plants by increasing salt and mineral fertilizer concentrations in the soil. As a result, the development of sustainable slow-release mineral fertilizers (SRFs) is critical for addressing salt-affected soils. This study aimed to synthesize struvite (MgNH 4 PO 4 ·6H 2 O) into hydrogel beads made from sodium alginate-poly (acrylic acid) in the absence (Sa@S) and presence (Sa@SHa) of humic acid (HA). The optimal conditions for struvite formation were at pH 9.0, resulting in a remarkable 73.21 %, 98.74 %, and 99.20 % for Mg, NH 4 -N and P removal, respectively. The SRFs study demonstrated that struvite had a significant release of Mg, P, and NH 4 -N, notably higher (P ≤ 0.05) than Sa@S and Sa@SHa. Experiments on swelling and soil water loss demonstrated that Sa@S yielded higher results in comparison to Sa@SHa. Furthermore, an experiment was conducted to study the impact of Sa@S and Sa@SHa on saline soil parameters over 20 days of incubation. The results showed both encapsulated struvite hydrogel beads reduced soil salinity, as indicated by the sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP). Additionally, a significant reduction (P ≤ 0.05) in soil electrical conductivity (EC) and sodium (Na) was observed for both hydrogel bead encapsulation treatments compared to the control soil. However, no apparent variance was observed in pH and soil organic carbon (SOC). Moreover, the levels of available phosphorus (P), ammonium-nitrogen (NH 4 -N), nitrate-nitrogen (NO 3 -N), cation exchange capacity (CEC), and exchangeable cations (Ca, Mg, K) in the soil were observed to be increased (P ≤ 0.05). [ABSTRACT FROM AUTHOR]

Poly(acrylic acid) is a synthetic polymer that is polymerized from acrylic acid monomers. Poly (acrylic acid) is a high molecular weight polymer having good water solubility. Poly(acrylic acid) also exists in the cross-linked forms. Poly(acrylic acid) is an important polymer for making polymeric blends and nanocomposites. This state-of-the-art review is an endeavour to define the unique capabilities of poly (acrylic acid) to form high performance nanocomposites. The nanofiller nanomaterials including carbon nanotube, graphene, nanodiamond, and inorganic nanoparticles are promising nanofillers for a poly(acrylic acid) matrix. Consequently, the article discusses the following categories: poly(acrylic acid)/carbon nanotube, poly(acrylic acid)/graphene, poly(acrylic acid)/nanodiamond, and poly(acrylic acid)/inorganic nanoparticle nanocomposites. The nanocomposite characteristics are significantly enhanced with the added nanoparticles. Especially, the nanoparticles influenced the electrical conductivity, thermal stability, strength, biocompatibility, adsorption, and anti-bacterial features of the poly(acrylic acid) nanocomposites. Their high performance was related to the interface interactions between the matrix and the nanofillers. The poly (acrylic acid) derived nanocomposites have been used to form advanced hybrid materials for batteries, sensors, antibacterial, and water filters. [ABSTRACT FROM AUTHOR]

The present work reports the construction of polypyrrole (PPy) hydrogels directly with the as-synthesized PPy nanotubes (PPy-NTs) through infiltration of poly vinyl alcohol (PVA) and poly(acrylic acid) (PAA) solutions. This method avoids the time-consuming purification of the in-situ formed conducting hydrogels and provides a facile way to incorporate nanostructured conducting polymers evenly into the hydrogel matrix. PPy-NTs/PVA/PAA hydrogels with dual cross-linking networks were prepared through multiple freeze-thawing cycles followed by coordination with iron (III) ions. The tensile and compression strength of the hydrogels are ca. 54 kPa and 160 kPa, respectively. The PPy-NTs/PVA/PAA hydrogel was mainly electronic conducting dominated, and it showed the highest conductivity of ca. 0.04 S/cm after swollen in 0.2 M HCl (with 2wt% of PPy-NTs). Benefited from the high aspect ratio and high conductivity of PPy nanotubes, it is probable to mediate the PPy content and the integrity of the electronic conducting pathways to develop high-performance hydrogel materials used as strain sensors. [ABSTRACT FROM AUTHOR]

Intrafibrillar mineralization is crucial in the synthesis of collagen‐hydroxyapatite (HAP) composites with hierarchical structure resembling natural bone. The polymer‐induced liquid precursor method, which involves immersing the matrix into polymer‐stabilized amorphous calcium phosphate (ACP) solutions, has been widely used to regulate collagen mineralization; however, heterogeneous infiltration and crystallization of ACP precursors from the surface to the inner matrix remain a concern. In this study, the polymer‐mediated co‐organization strategy in which poly (acrylic acid) (PAA)‐stabilized ACP solutions were initially introduced to collagen solutions before sol–gel transformation was employed to achieve homogeneous mineralization. Moreover, the effects of PAA with various molecular weights (2, 10, and 450 kDa) and concentrations (40, 80, and 120 mg/L) on collagen mineralization were evaluated. Increasing concentration and decreasing molecular weight both improved the stability of ACP precursors, which affected collagen mineralization. A lower concentration (40 mg/L) of 2 kDa PAA and higher concentration (80 and 120 mg/L) of 100 and 450 kDa PAA effectively retarded ACP crystallization, thereby inducing intrafibrillar mineralization. Extremely unstable ACP precursors failed to infiltrate the interior of fibrils using 100 and 450 kDa of PAA at 40 mg/L, resulting in extrafibrillar mineralization. Inversely, collagen fibrils were unmineralized until 7 days owing to excessive stability of ACP precursors using 2 kDa of PAA at higher concentrations. The present results further explain the mechanisms of intrafibrillar mineralization, and may provide a facile method for producing biomimetic materials. [ABSTRACT FROM AUTHOR]

Silver (Ag) has been used to cross-link poly (acrylic acid) (PAAc) to obtain antibacterial nanocomposite hydrogel for controlled drug delivery systems. Ag+/PAAc composite hydrogel was prepared by free radical aqueous polymerization of acrylic acid (AAc) using potassium persulfate (KPS) as the initiator in the presence of silver nitrate (AgNO 3). Sodium borohydride (NaBH 4) was used to reduce the Ag ions present within the hydrogel matrix to generate Ag nanoparticles (Ag NPs). Transmission electron microscopy (TEM) characterization of the sample indicated the formation of Ag nanoparticles that distributed uniformly in the PAAc networks. UV–visible spectrophotometry showed an absorption peak at 425 nm that attribute to the well-known surface Plasmon resonance of the Ag bound in NPs. X-ray diffraction (XRD) pattern showed the appearance of some peaks corresponding to the face-centered cubic (f.c.c.) Ag phase. Energy dispersive spectroscopy (EDS) studies revealed that Ag NPs are successfully formed inside the Ag+/PAAc composite hydrogel. The gelation and crosslinking of PAAc chains with Ag+ by strong interactions between Ag cations and polyanions, deprotonated carboxylic groups of PAAc were identified from the Fourier transform infrared (FTIR) spectrogram. Field emission scanning electron microscopy (FESEM) exhibited an interconnected porous structure with an average pore size of about 10 μ for composite hydrogel that can absorb 440 g water/g dried sample. Dried samples were also loaded with amoxicillin and antibiotic release was studied. The antimicrobial activity of the Ag+ and Ag-NPs hydrogels was tested against Staphylococcus aureus , Bacillus cereus, Pseudomonas aeruginosa and Escherichia coli. • Ag has been used to cross-link poly (acrylic acid) (PAAc) to obtain antibacterial nanocomposite hydrogel. • The synthesis processes of the present antibacterial nanocomposite were ecofriendly with the utilization of water. • A simple and effective method has been introduced for Ag nanoparticles to form uniformly inside the polymer matrix. • This methodology as a general and versatile method could be applicable for synthesizing other metal nanoparticles. [ABSTRACT FROM AUTHOR]

The aim of this work is to prepare nanofibrous scaffolds based on poly (l -lactide- d , l -lactide)/poly (acrylic acid) [PLDLLA/PAAc] blends in the presence of Dexamethasone [Dexa]-loaded poly (2-hydroxyethyl methacrylate) [HEMA] as molecular imprinted polymer [MIP] nanoparticles [NPs] for enhancing osteogenesis. By adding 10 wt% of PAAc to the PLDLLA and employing response surface methodology, the average diameter of the electrospun nanofibers is approximately 237 nm. To increase the osteogenesis performance of the optimized nanofibrous scaffolds, the MIP nanoparticles are synthesized using HEMA monomer and Dexa template with a molar ratio of 10 to 1. Accordingly, these crosslinked drug nanocarriers exhibit an average diameter of around 122 nm and imprinting factor of approximately 1.8, enabling to adsorb Dexa molecules around 57%. Afterward, the Dexa-loaded MIP NPs have capability of a controlled drug release with ultimate value of 60% during 72 h. The simultaneous use of PLDLLA/PAAc-10 nanofibrous scaffold and Dexa-loaded MIP NPs within the cultivation media of fibroblast and mesenchymal stem cells is carried out by thiazolyl blue assay and acridine/ethidium bromide staining as well as alkaline phosphate/calcium content test, and alizarin red staining. The results reveal the remarkable efficiency of the blend nanofibers besides the MIP containing Dexa, thereby using for bone tissue engineering applications, potentially. Unlabelled Image [ABSTRACT FROM AUTHOR]

Fungal infection in immuno compromised patients causes skin syndromes and problems. At Present, innovative alternatives are required to cure skin disorders and infections. Luliconazole is a novel, broad spectrum, imidazole antifungal agent. The purpose of this study was to develop biodegradable, pH responsive, chemically cross-linked and Poly (acrylic acid) grafted sodium carboxymethyl cellulose nanogels. Nanogels had been synthesized to evaluate its applicability as an effective carrier of luliconazole for topical (skin) targeting. Chemically cross-linked sodium carboxymethyl cellulose-grafted-Poly acrylic acid (NaCMC-g-PAA) was synthesized from acrylic acid and sodium carboxymethyl cellulose using N, N'-methylene bisacrylamide (cross-linker) and potassium persulfate (initiator) using free radical polymerization. Variation of reaction parameters such as pH, cross linker, initiator and temperature has been used to optimize the best one. The developed nanogels reveal significant pH sensitive drug releasing behavior. NaCMC-g-PAA nanogels has been characterized using various physicochemical characterization techniques. Nanogels characteristics were evaluated through the In vitro drug release, Ex vivo permeation study, Nuclear magnetic resonance spectroscopy, Fourier Transform Infrared Spectroscopy, Field Emission Scanning Electron Microscope, Stability Study and antifungal activity. All batches were characterized for particle size analysis and ranged from 78.82 nm to 190 nm. The viscosity of developed nanogels was found to be 5941 cps. It was observed that the developed drug-loaded NaCMC-g-PAA nanogels were more effective in killing the fungus. Consequently, Nanogels incorporated with luliconazole could be a new approach with improved antifungal activity and increased topical delivery for a drug with poor aqueous solubility rather than coarse drug-containing cream. [ABSTRACT FROM AUTHOR]

In the present study, semi-interpenetrating polymer networks (semi-IPNs) were synthesized based on crosslinked acrylic acid (AA)/xanthan gum (XG) biopolymer in the presence of N, N′-hexane-1, 6-dilbisprop-2-enamide (MS) or 1,4-butandioldimethacrylate (BDOD) as the cross-linking agent. MS is a novel acrylic-urethane diene monomer prepared through the condensation reaction between AA and hexamethylene diisocyanate (HDI). Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), proton nuclear magnetic resonance spectroscopy (1H NMR), X-ray diffraction (XRD) and thermogravimetric (TGA) analyses were used to study the morphology, structure and thermal stability of MS and semi-IPNs. The effect of crosslinking agent type on different behaviors such as morphology, stability, swelling, and water-retention capabilities of the synthesized hydrogels were investigated. XG-PAA semi-IPNs exhibited a very high adsorption potential and stability. Hydrogel biocompatibility was confirmed by the outcomes of MTT assay and cell staining. We recommend XG-PAA semi-IPNs as an environmentally benign and readily non-toxic material with an excellent adsorption capacity for application in drug delivery systems, wound healing and dye removal. Unlabelled Image • Eco-friendly semi-interpenetrating polymer networks were synthesized based crosslinked acrylic acid onto xanthan gum. • N, N′-hexane-1, 6-dilbisprop-2-enamide (MS) and 1,4-butandioldimethacrylate (BDOD) used as a cross-linking agent. • Hydrogels cross-linked by MS had more and large porosity due to the reaction of residual groups of isocyanate. • By increasing the amount of cross-linker in both cases, the amount of swelling ratio decreased. • The synthesized hydrogels have intelligent swelling ratio at different pH levels. [ABSTRACT FROM AUTHOR]

Drilling fluid is a vital element and is often regarded as the "blood" in the oil industry. Although traditional oil-based drilling fluids have advantages in some harsh cases, the high cost and environmental pollution faced with them limit its application. Water-based drilling fluids (WBDFs) with environmental friendly, low cost, and high performance are important for drilling engineering to solve the problems of low efficiency and wellbore instability caused by poor rheological properties and large filtration loss in drilling operations. In this paper, Fe3O4 nanoparticles modified by poly (acrylic acid) (PAA) through 3-(trimethoxysilyl) proryl methacrylate (TMSPMA) were introduced into WBDFs for enhancing their rheological and plugging performance. Rheological tests indicated that the consistency coefficient (K) of the Fe3O4/PAA nanoparticles/WBDFs decreased at a higher concentration. Incorporated nanoparticles with a concentration of 0.05 wt %, the WBDFs will exhibit good shear-thinning behavior. The results showed that the best performance for Fe3O4/PAA nanoparticles being as a filtration additive in WBDFs was achieved at concentration as low as 0.1 wt %. These results demonstrated that Fe3O4/PAA nanoparticles are effective additives for WBDFs. [ABSTRACT FROM AUTHOR]

Abstract Aqueous binders have recently received great attention for lithium ion batteries due to its good stability and safety. Herein, poly (acrylic acid)/poly (vinyl alcohol) (PAA/PVA) blends have been used as a binder for lithium iron phosphate (LiFePO 4 /C) cathodes. This blending system not only can form a stable network by hydrogen-bonding interactions leading to an increase in the amount of binder covering the surface of active materials, but also can significantly enhance the adhesion strength of electrodes. Additionally, The conductive agent and active materials are uniformly distributed due to the interaction between PAA/PVA blending binder and electrode materials, which it is beneficial to Li+ conduction in the electrode. These unique properties result in lower polarization and interfacial resistance of the electrode, thus considerably overcoming the limitation of LiFePO 4 /C electrodes for electrochemical performance. It is believed that this blending binder has a great potential to be used for commercial lithium ion batteries. Highlights • PAA/PVA blends have been successfully used as a binder for LiFePO 4 /C cathodes. • A stable network by hydrogen-bonding interactions was formed in this blending system. • An increase in the amount of binder covering the active materials was obtained. • An improvement adhesion strength of electrodes was obtained. • Superior electrochemical properties of the electrodes with this binder were obtained. [ABSTRACT FROM AUTHOR]

The successful use of biosensors requires that the sensor can operate over abroad enough linear range that encompasses the physiological concentration of the substrate of interest. A polymer coating layer functioning as a mass‐transport barrier is typically used to expand the linear range of biosensors with, however, the concomitant disadvantage of a reduction in the response. Effects of a poly(acrylic acid) coating layer on the response of a glassy carbon electrode modified with an Os redox polymer and lactate oxidase were evaluated. The coating layer resulted in an expanded linear range from 7 to 15 mM, doubled catalytic response towards the oxidation of 35 mM lactate, and improved operational stability. Detailed voltammetry studies revealed that the coating layer can improve the amount of the redox polymer that is available as a mediator, leading to the increased catalytic response at high concentrations of substrate. Similar results were obtained with other polymer layers [polystyrene sulfonate, poly(diallyldimethyl‐ammonium chloride), and poly(3,4‐ethylenedioxythiophene)] and with the enzymes glucose oxidase and bilirubin oxidase, demonstrating the general nature of the method. Grab your coat: A poly(sodium 4‐styrenesulfonate) coating layer shows enhancement effects for a bioanode based on osmium redox hydrogel film incorporating lactate oxidase. [ABSTRACT FROM AUTHOR]

Abstract Poly (l -lactide- co -D, l -lactide) (PLDLLA) is a biodegradable polymer predominantly used in biomedical applications. Despite unprecedented characteristics of PLDLLA, its wettability, mechanical properties, degradation, and cell attachment are main issues to improve. In this work, different blend films based on PLDLLA/poly (acrylic acid) (PAAc) are prepared to evaluate their miscibility, hydrophilicity, hydrolytic degradation and mechanical properties. For this purpose, a series of experiments such as DSC alongside SEM, water contact angle (WCA)/water up-take, weight measurements in phosphate buffer saline (PBS) and NaOH as well as tensile test are carried out. The DSC and SEM results show a miscibility for the blends, and hence by increasing PAAc, the WCA values and degradation rates are decreased and increased, respectively. Moreover, the degradation mechanisms of the blend samples follow surface/bulk erosion and bulk process in the alkaline and PBS environments, respectively. Subsequently, PLDLLA and its blends are electrospun to prepare nanofibrous samples, thereby assessing their cytotoxicity and cell viability by the use of thiazolyl blue assay and acridine orange/ethidium bromide staining, respectively. The in vitro SNL 76/7 fibroblast cells cultivation onto the surface of the blend with 10% wt. of PAAc revealed that this sample is a promising candidate for tissue engineering applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Flocculation is a widely used method to treat wastewater effluents. Aluminum oxide particles have been recognized as major parts of effluents of ceramic industries. In this work, the flocculation of aluminum oxide particles with various sizes (0.06-0.6 μm) was analyzed using poly(acrylic acid) (PAA) to investigate how the flocculation effectiveness of PAA would be affected by the particle size of aluminum oxides. The zeta potential of the suspensions was changed to a similar extent by PAA, regardless of aluminum oxide particle size, implying that the diffuse double layer of the particles was affected in a similar manner despite different adsorption amounts of PAA. The relative turbidity of the suspensions was remarkably reduced for the aluminum oxide with the largest particle size (AL1) and was less affected by aluminum oxide with smaller sizes (AL3). The chord length of the produced flocs was pronouncedly increased by increasing the particle size of aluminum oxide and the floc counts was reduced substantially. The sedimentation studies of the suspensions revealed more efficient sedimentation behavior for AL1/PAA flocs than for AL1 and AL3 based flocs. The settling velocity and sedimentation compactness of the flocs were also analyzed in this study. [ABSTRACT FROM AUTHOR]

We investigate the effects of carboxymethyl cellulose (CMC) and poly (acrylic acid) (PAA) on the dispersion state of silicon particles and the mechanism thereof. Here, we report severe agglomeration of silicon particles induced by the hydrophobic interaction arising from CMC(degree of substitution; DS 0.7). Although the adsorption amount of CMC (DS 0.7) onto the silicon surface is comparable to that of PAA, its effect on particle dispersion is significantly different. The agglomeration mechanism is systematically explored in terms of polymer-polymer and particle-polymer interactions by varying the DS of CMC and the pH of the suspensions. We demonstrate that the attraction between polymers adsorbed on the silicon surface and the affinity between the particle and polymer determine the degree of silicon agglomeration. The hydrophobic attraction of CMC(DS 0.7) promotes silicon agglomeration significantly, whereas CMC(DS 1.2) deficient in attraction disperses silicon particles well. Silicon particles weakly agglomerate in Si/PAA suspensions due to hydrogen bonding between PAA chains and due to the high affinity between PAA and the silicon surface. The dispersion of Si/CMC(DS 0.7 or 1.2)/PAA suspensions is primarily dominated by PAA through its high affinity with silicon and corresponding favorable adsorption on the silicon surface. This is the first attempt to quantitatively assess and compare the impact of CMC and PAA on the agglomeration behavior of silicon particles and reveal the underlying mechanism. This paper provides a fundamental understanding to control the dispersion homogeneity and stability of silicon-containing electrodes. [Display omitted] • The hydrophobic attraction of CMC(DS 0.7) results in significant Si agglomeration. • The H-bonding of PAA and high affinity for the Si surface promote weak Si agglomeration. • The PAA adsorbed on the Si surface, rather than free CMC in the medium, dominates the dispersion state of Si particles. [ABSTRACT FROM AUTHOR]

Aqueous-based C/LiFePO4 positive electrodes with high-rate capabilities are described with an intended application in lithium ion batteries. Pastes consisting of C/LiFePO4 particles, sodium carboxymethyl cellulose (CMC), water-soluble elastomeric binder (WSB) and poly (acrylic acid) (PAA) were prepared in an aqueous medium and tape-cast onto an aluminum foil. It was found that the incorporation of PAA significantly decreased the apparent viscosity of the C/LiFePO4 paste as well as shifted particle size distribution to lower value, which resulted in an improvement of the C/LiFePO4 dispersion properties. A correlation was made between the dispersion properties and the electrochemical properties. The electrochemical properties indicated that the electrode with PAA exhibited a discharge specific capacity above 70 mAhg−1 at 20C, which was about seven times higher than the discharge specific capacity without PAA at 20C which showed a discharge specific capacity of only 10 mAhg−1. This was attributed to the formation of a resistance-imparting agglomeration, which is consistent with the dispersion properties of C/LiFePO4 particles.

Cellulose nanocrystals are considered as promising biomass nanofillers for polymeric hydrogels, but poor interface compatibility between cellulose nanocrystals and hydrogel matrix usually reduces their reinforcement effect. Here, we reported a novel interface compatible nanocomposite hydrogel prepared by introducing quaternized tunicate cellulose nanocrystals (Q-TCNCs) into chemically cross-linked poly (acrylic acid) (PAA) networks. Q-TCNCs acted as both nanofillers and physical cross-linkers in the PAA networks, and the electrostatic interaction between the positive charges of Q-TCNCs and negative charges of PAA chains improved their interface compatibility. The nanocomposite hydrogels exhibited controllable swelling ratio and pH-sensitive swelling behaviors. The mechanical properties of hydrogels significantly increased after incorporation of Q-TCNCs. Moreover, the nanocomposite hydrogels exhibited partly recoverable ability due to the presence of reversible electrovalent bonds in the hydrogel networks. [ABSTRACT FROM AUTHOR]

A hydrogel nanocomposite composed of reduced graphene oxide (RGO), iron oxide (Fe 3 O 4 ) nanoparticles, and polyacrylic acid (PAA) was prepared using radical polymerization. Different percentages of RGO, Fe 3 O 4 , and PAA were used to prepare the nanocomposite. Fourier transform infrared spectroscopy (FTIR) results confirmed the formation of the nanocomposite’s chemical structure. X-ray power diffraction (XRD) patterns revealed the principal peak’s 2θ value to be 77.39° with the size of the nanocomposite particles estimated at 96 nm. Results indicated that the electrochemical capacity of the nanocomposites was controlled by the weight percentage of RGO. Increases to the potential scan rate reduced porosity and surface area, thereby decreasing the electrochemical capacity of the nanocomposites. Moreover, increasing the percentage of Fe 3 O 4 nanoparticles in the nanocomposites improved their magnetic characteristics and thermal properties. The latter also improved when the RGO percentage increased. [ABSTRACT FROM AUTHOR]

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A water-in-oil (W/O) emulsion, in which the water phase including poly (acrylic acid) (PAA), ammonium hydroxide (NH 3 aq.), and sodium hydroxide aqueous solutions (NaOH aq.) dispersed in ethanol (EtOH), was proposed for producing hollow silica nanoparticles. The PAA molecules with the NH 3 -NaOH mixture are insoluble in EtOH and can be a template. When tetraethoxysilane (TEOS) is added as a silica source, a silica shell is formed on the PAA-NH 3 -NaOH template to form a core-shell particle and the addition of water removes the template to form hollow silica nanoparticles. The optimum volume ratio of 25% NH 3 :1.0 M NaOH was 2:1 to obtain high-dispersed hollow silica nanoparticles. A thermogravimetric analysis indicated that the condensation force of the PAA molecules in the PAA-NH 3 -NaOH template is similar to that in the PAA-NH 3 template. The small angle X-ray scattering (SAXS) analysis also showed that the electron densities in the PAA-NH 3 -NaOH and PAA-NH 3 templates are similar. In the proposed PAA-NH 3 -NaOH system, NH 3 aq. mainly contributes to form PAA condensation by an ionic interaction and NaOH aq. preferentially work as a sol-gel catalyst for the fast silica coating on the template surface. [ABSTRACT FROM AUTHOR]

Quantifying the effect that nanofiber mat chemistry and hydrophilicity have on microorganism collection and inactivation is critical in biomedical applications. In this study, the collection and inactivation of Escherichia coli K12 was examined using cellulose nanofiber mats that were surface-functionalized using three polyelectrolytes: poly (acrylic acid) (PAA), chitosan (CS), and polydiallyldimethylammonium chloride (pDADMAC). The polyelectrolyte functionalized nanofiber mats retained the cylindrical morphology and average fiber diameter (~0.84 µm) of the underlying cellulose nanofibers. X-ray photoelectron spectroscopy (XPS) and contact angle measurements confirmed the presence of polycations or polyanions on the surface of the nanofiber mats. Both the control cellulose and pDADMAC-functionalized nanofiber mats exhibited a high collection of E. coli K12, which suggests that mat hydrophilicity may play a larger role than surface charge on cell collection. While the minimum concentration of polycations needed to inhibit E. coli K12 was 800 µg/mL for both CS and pDADMAC, once immobilized, pDADMAC-functionalized nanofiber mats exhibited a higher inactivation of E. coli K12, (~97%). Here, we demonstrate that the collection and inactivation of microorganisms by electrospun cellulose nanofiber mats can be tailored through a facile polyelectrolyte functionalization process. [ABSTRACT FROM AUTHOR]

This article describes a new cross-linking mechanism for synthesizing PAA microgels by precipitation polymerization method. The post curing stage was defined, for the first time, in this study. Effect of cross-linker concentration, and the time and temperature of post curing stage on the samples properties was investigated. A new relationship between gelation rate in the post curing stage and hydroxyl content was defined. Also a new relationship betweenMc, hydroxyl concentration and temperature of post curing stage was suggested too. According to rheological characterization, microgels synthesized by novel mechanism have better rheological properties than microgels synthesized by conventional mechanism. [ABSTRACT FROM PUBLISHER]

In the present work, we study the effect of experimental conditions on the performance of polyelectrolyte-enhanced ultrafiltration for the removal of Toluidine blue from aqueous solution. The dye solution was processed by ultrafiltration using a regenerate cellulose membrane with pore sizes small enough to block the passage of the polymer and then the complexed dye ions. The experiments showed that retentions as high as 99% and 97% were obtained for PAA and PANH4, respectively, due to the strong electrostatic interaction between anionic polyelectrolytes and cationic dye.The increase of retention was linked to the complexation of the dye by polyelectrolyte while the decrease of the permeate flux was attributed to the accumulated macromolecular complex near the membrane. [ABSTRACT FROM AUTHOR]

Some physical properties of poly (acrylic acid) gels with embedded gold nanoparticles, (PAA-GNP), as prepared and after neutralization with triethanolamine, (TEA), were investigated by UV-VIS and fluorescence methods. The UV-VIS spectra of the PAA-GNP gels contain the characteristics absorption peaks of both PAA and GNP pure components, with modified intensities and positions. Excitation at 250 nm of pure PAA and pure GNP are followed by characteristic fluorescence transitions. The peaks of pure components appear in the fluorescence spectrum of the PAA-GNP gels with some modifications compared with the pure state. Some modifications of the UV-VIS and florescence spectra were observed after neutralization with TEA. The particularities of these spectra indicate some changes of the conformation of the polymeric matrices after the introduction of GNP and after neutralization. [ABSTRACT FROM AUTHOR]

Abstract: We present the development of flexible secondary alkaline battery with rechargeability similar to that of conventional secondary alkaline batteries. Multiwalled carbon nanotubes (MWCNTs) were added to both electrodes to reduce internal resistance, and a cathode containing carbon black and purified MWCNTs was found to be most effective. A polyvinyl alcohol–poly (acrylic acid) copolymer separator served the dual functions of electrolyte storage and enhancing flexibility. Additives to the anode and cathode were effective in reducing capacity fades and improving rechargeability. [Copyright &y& Elsevier]

Poly(acrylic acid) ( PAA) and poly(ethylene glycol) (PEG), four-arm, amine-terminated particles with nanometer size and spherical shape were obtained by the polymers cross-linking, via activation with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride, in a w/o emulsion. The morphology and surface charge of the final particles are strongly dependent on the molar ratio of PAA- PEG and the PAA concentration. The physicochemical characteristics correlated with the drug-loading capacity, in vitro and ex vivo release kinetics of pilocarpine hydrochloride and biocompatibility results indicate that these nanoparticles exhibit the prerequisite behavior for use as carriers of ophthalmic drugs. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:676-686, 2014 [ABSTRACT FROM AUTHOR]

pH-sensitive poly (vinylidene fluoride) (PVDF)/poly (acrylic acid) (PAA) microgels membranes are prepared by phase inversion of the N, N-dimethylformamide solution containing PAA microgels and PVDF in aqueous solution. The composition and structure of the blend membrane are investigated by Fourier transform infrared spectra, X-ray photoelectron spectroscopy measurements, thermo gravimetric analysis, field-emission scanning electron microscope and atomic force microscope. The results indicate the surface and cross section of the blend membranes have a porous structure with PAA microgels immobilized inside the pore and on the membrane surface. The blend PVDF membranes exhibit pH-sensitive water flux, with the most drastic change in permeability observed between pH 3.7 and 6.3. The blend membranes are fouled by bovine serum albumin, and their antifouling property is enhanced by increasing PAA microgels, mainly derived from the improved hydrophilic property. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Highlights: [•] A novel electrical-sensitive poly (NVP-co-AA) hydrogel was prepared from linear copolymer. [•] Gelation mechanism was studied by FTIR and solid-state CP/MAS NMR techniques. [•] Swelling and bending phenomenon of the hydrogel were investigated under an electric field. [•] The bending mechanism was reinterpreted. [Copyright &y& Elsevier]

In the present work, a new porous low density lipoprotein (LDL) adsorbent membrane is prepared by 60Co γ-ray irradiation-induced grafting copolymerization of polypropylene (PP) non-woven fabric with acrylic acid, followed by immobilizing heparin covalently. The amount of carboxyl group and heparin on the resultant PP non-woven fabric is determined by titration and colorimetry, respectively. The new adsorbent membrane is characterized by attenuated total reflection Fourier transform infrared spectroscopy, scanning electron microscope, and contact angle microscopy. Static adsorption and hemoperfusion tests indicate this new adsorbent can efficiently and selectively remove LDL from human plasma. Meanwhile, good adsorption of triglyceride (TG) is also obtained. The best result is achieved by the adsorbent membrane P0.45-A15-H, where 33.3 ± 2.9 µg of LDL-C, 14.7 ± 1.9 µg of high density lipoprotein cholesterol (HDL-C), 64.9 ± 4.3 µg of total cholesterol (TC), and 202.4 ± 5.7 µg of TG are removed from human plasma per square centimeter. Hemocompability and toxicity tests show this new adsorbent membrane has good blood compatibility and low toxicity. Considering the adsorbent performance, safety, low cost, and simple preparation, this new adsorbent membrane has potential clinical application for removal of LDL. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

To improve caprolactam pervaporation (PV) separation dehydration process, composite membrane was investigated using chitosan (CS) and poly (acrylic acid) (PAA) blending membrane as active layer and a polyacrylonitrile (PAN) ultrafiltration membrane as substrate. The composite membranes were characterized by FTIR, SEM, and XRD measurements to assess the intermolecular interactions membranes of morphology, and observe the crystallinity, respectively. The effect of the ratio of PAA and CS in the composite membranes on the PV performance was investigated. The flux was decreased and the separation factor was increased by the PAA content increase in the range of 10-30 wt.%. Besides, operating temperature and feed composition on PV performances were investigated. Data showed that PAA/CS composite membranes displayed good swelling and PV performance, and the composite membranes had superior separation performances for dehydration of ε-caprolactam solution, that the highest separation factor could reach 7,804 at 313 K, for 70 wt.% caprolactam. The evaluated results revealed that the separation performances of CS/PAA composite membranes were strongly related to their reaction degree and intrinsic structure as well as the operating parameters. [ABSTRACT FROM AUTHOR]

Abstract: A microporous hybrid polymer of poly(acrylic acid)/gelatin/polyaniline (PAA/Gel/PANI) is synthesized with a two-steps solution polymerization. Using this hybrid as polymer host, a gel-electrolyte with a high liquid absorbency of 16.45 (gg−1) and a high conductivity of 14.38mScm−1 is prepared, then a quasi-solid-state dye-sensitized solar cell (QS-DSSC) is assembled. The polymer host is characterized by scanning electron microscopy (SEM), the functional groups on the polymer are identified by Fourier transform infrared spectroscopy (FTIR) and the photovoltaic tests of the QS-DSSCs are carried out by measuring current–voltage (I–V) curves. The QS-DSSC with this hybrid gel-electrolyte achieves a light-to-electric energy conversion efficiency of 6.94%. [Copyright &y& Elsevier]

Abstract: A microporous hybrid polymer of poly(acrylic acid)-g-cetyltrimethylammonium bromide/polyaniline (PAA-g-CTAB/PANI) was synthesized by a two-steps solution polymerization. Using this amphipathic hybrid as host, a gel-electrolyte with a high absorbency of 17.69 (g/g) and a high conductivity of 14.29mScm−1 was prepared. The polymer hosts have been characterized by means of scanning electron microscopy (SEM), and the microporous network structure was observed. Fourier transform infrared spectroscopy (FTIR) and the electrochemical property tests of the gel-electrolytes have been carried out by means of I–V measurements. The quasi-solid-state dye-sensitized solar cells (QS-DSSCs) based on the hybrid gel-electrolyte reach a light-to-current efficiency of 6.68%. [Copyright &y& Elsevier]

Semiconductor quantum dots (QDs) are promising fluorescence probes for immuofluorescence assay in the biological applications. However, water solubilization and non-specific binding are two critical issues to be addressed for the practical uses. Here, we reported a new type of QDs with combined silica and polymer coating. QDs with excellent colloidal properties were prepared via carboxylation of the amino groups on the surface of silica-coated QDs by reacting with multi-carboxyl poly (acrylic acid) (PAA). Hydrodynamic size of PAA-functionalized silica-coated QDs was around 40 nm. They were highly fluorescent (about 47.8% quantum yield). No precipitate of QDs was observed after 3 month storage at 4 °C. When cancer cells (HeLa) were used, the functionalized QDs exhibited little or no non-specific cellular binding. The results from in vitro experiments indicated that PAA-functionalized silica-coated QDs-antibody bioconjugates had excellent antigen-capture ability and exhibited little or no non-specific binding to polystyrene spheres which were used to immobilize the antigen for immuoflurescence assay. The PAA-functionalized silica-coated QDs with improved colloidal properties could serve as excellent alternative fluorescent probes for biodetection. [ABSTRACT FROM AUTHOR]