Co-acrylic Acid Research Articles

Smart microsubmarine shells operated by controlled buoyancy force through metal-ion adsorption/desorption and their biosensor applications

Small and uniform-sized poly(polyethylene glycol (PEG)–co-acrylic acid (AA)) shells engulfing a mineral oil droplet (oil@poly(PEG-co-AA) shells, ∼180 μm) are prepared using the in situ polymerization of the O(mineral oil)–W(PEGDA/AA, PEGDA = polyethylene glycol diacrylate)–O(mineral oil) double emulsion droplets produced in a microfluidic chip. The lightweight oil core and heavy-weight poly(PEG-co-AA) shells exhibit positive buoyancy and negative gravitational forces in water, respectively. Densities of oil@poly(PEG-co-AA) shells were finely tuned in water to be sensitive to a small weight change by controlling microfluidic parameters. The poly(PEG-co-AA) shells are pH-responsive in terms of charged state and shell size. The pH-controlled metal adsorption/desorption at poly(PEG-co-AA) shells breaks the density balance, leading to the sinking or floating of oil@poly(PEG-co-AA) shells in the water. Herein, this levitation and size change of oil@poly(PEG-co-AA) shells are applied to glucose and urea biosensors by immobilizing their enzymes. The divalent (or higher) metal adsorption is distinguishable from monovalent metal adsorption by the diminished size of the oil@poly(PEG-co-AA) shells and their different levitation behavior in water. Thus, these oil@poly(PEG-co-AA) shells facilitate smart motile sensor applications with an unexplored concept, which can be further expanded to other applications such as smart valves in microfluidics and smart windows.

Zero Valent Iron Impregnated Sodium Alginate Grafted (Acrylamide-Co-Acrylic Acid) Adsorbents for the Removal of Methylene Blue in Aqueous Systems

In this study sodium alginate (NaAlg) grafted acrylamide (AM)-co-acrylic acid (AA)) and nano zero-valent iron (nZVI) were synthesized by the microwave assisted and coprecipitation method, respectively. The nZVI was dispersed in NaAlg-g-(AM-co-AA) and the adsorbent was characterized by X-ray diffraction (XRD), proton nuclear magnetic resonance (1HNMR), and Fourier transform infrared spectroscopy (FTIR). In order to evaluate the effects of adsorbent dosage, contact time, pH, initial dye concentration and temperature, kinetic and thermodynamic tests were carried out on the adsorbents. The best dose of the NaAlg-g-(AM-co-AA)/nZVI with 0.5% nZVI needed to remove methylene blue (MB) dye (10 mg/L, 50 mL) was 0.2 g at 60 min. For NaAlg-g-(AM-co-AA)/nZVI to effectively remove a large portion of MB dye, pH 8.0 was ideal. To assess the adsorption data, Freundlich, Langmuir, and Dubinin-Radushkevich isotherm models were applied. The Langmuir isotherm performed best for MB adsorption, with an R2 of 0.975. The adsorption equilibrium’s kinetic process followed the pseudo-second-order model (R2=0.9988). The positive ΔGo values obtained from the thermodynamic studies showed that the adsorption processes were endothermic and non-spontaneous.

The effect of ZIF-8 nanoparticle concentration on microwave-assisted synthesis of poly (vinyl alcohol)-co-acrylic acid copolymeric membranes and their potential application in fuel cell

The effect of ZIF-8 nanoparticle concentration on microwave-assisted synthesis of poly (vinyl alcohol)-co-acrylic acid copolymeric membranes and their potential application in fuel cell

Temperature sensitive nanogels for real-time imaging during transcatheter arterial embolization

ABSTRACTSeveral vascular embolization materials are commonly used in clinical practice, however, having application defects of varying degrees, such as poor intraoperative imaging and easy recanalization of embolized blood vessels, they are challenging for application during Transcatheter arterial embolization (TAE). Thus, an intraoperative visible vascular embolization material with good embolization effect and biocompatibility can improve transcatheter arterial embolization clinical efficacy to some extent. Our study aimed to synthesize a novel vascular embolization material that can achieve complete embolization of arterial trunks and peripheral vessels, namely poly (N-isopropyl acrylamide)-co-acrylic acid nanogel (NIPAM-co-AA). Iohexol 200 mg/mL was co-assembled with 7 wt% NIPAM-co-AA nanogel to create an intelligent thermosensitive radiopaque nanogel (INCA), which achieves a good intraoperative imaging effect and is convenient for transcatheter arterial bolus injection due to its good fluidity and temperature-sensitive sol-gel phase transition. The normal rabbit kidney embolism model further confirmed that INCA could effectively use Digital subtraction angiography (DSA) to achieve intraoperative imaging, and real-time monitoring of the embolization process could avoid mis-embolization and leakage. Meanwhile, in a 42-day study, INCA demonstrated an excellent embolization effect on the right renal artery of New Zealand white rabbits, with no vascular recanalization and ischemic necrosis and calcification remaining. As a result, this radiopaque thermosensitive nanogel has the potential to be an intelligent thermosensitive medical vascular embolization material, providing dual benefits in TAE intraoperative imaging and long-term postoperative embolization while effectively addressing the shortcomings and challenges of commonly used clinical vascular embolization agents.

Development of a water-based functional additive by using isobornyl acrylate copolymer to improve ink-adhesion on untreated polypropylene surfaces: A comparative approach

The good barrier and hot-fill properties of polypropylene (PP) films and sheets make packaging industries advantageous. However, printing over a PP substrate is a major issue encountered in the packaging industry. The present study intends to prepare, characterise, and compare isobornyl acrylate (IBOA)-co-acrylic acid (AA) and isobornyl acrylate (IBOA)-co-methacrylic acid (MAA) based non-halogenated functional additives by using oil in water emulsion processes. The bornyl group of IBOA helps in enhancing molecular bonding with the polypropylene (PP) surface. The various properties of these synthesised functional additives were characterised using dynamic light scattering-particle size and zeta potential analysis, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermal gravimetric analysis (TGA), and gel permeation chromatography (GPC). The adhesion of these functional additive incorporated ink samples on different untreated PP surfaces was compared using the cross-cut adhesion test. The methacrylic acid based functional additive shows better adhesion properties as compared to acrylic acid.

Effect of Hydrophobic Side Group on Structural Heterogeneities and Mechanical Performance of Gelatin-Based Hydrogen-Bonded Hydrogel

Hydrogen bonds stabilized by hydrophobic side groups have been widely applied to realize high toughness of hydrogels. Herein, we studied the effect of the content of the hydrophobic methyl side group on the structure and mechanical properties of tough hydrogen-bonded gelatin/poly (methacrylic acid–co-acrylic acid) (G/Mx-Ay) hydrogels by alternating the content of methacrylic acid (MAA) in the methacrylic acid–acrylic acid copolymer (MAA-co-AA). The content of MAA did not affect the hydrogen-bond formation between the MAA-co-AA and gelatin but affected the phase-separated structure. With an increase in the MAA content, the local structure of the hydrogels with similar water content transformed from a “network” structure to a “bicontinuous” phase-separated structure and to a phase-separated structure with wide size distribution. The hydrogels with the same structure exhibited similar viscoelastic behaviors, and the G/Mx-Ay hydrogels with “bicontinuous” phase separation exhibited the best mechanical properties with an optimal Young’s modulus of ∼7.5 MPa and fracture tensile stress of ∼10 MPa.

Poly(2-ethyl hexyl acrylate-co-methyl allyl polyethylene glycols ether–co-acrylic acid) pressure-sensitive adhesives: synthesis, characterization, investigations of adhesive and thermal properties

Poly(2-ethyl hexyl acrylate-co-methyl allyl polyethylene glycols ether–co-acrylic acid) pressure-sensitive adhesives: synthesis, characterization, investigations of adhesive and thermal properties

Enhanced anti-tumor activity of a drug through pH-triggered release and dual targeting by calcium phosphate-covered mesoporous silica vehicles.

Rapid release and clearance of antitumor drugs in vivo are the main factors used to evade the effectiveness of chemotherapeutics. Targeted delivery and controlled release of drugs are the most pressing dilemmas in cancer therapy. Herein we report the design and fabrication of multifunctional mesoporous silica nanoparticles coated with poly(N-isopropylacrylamide)-co-acrylic acid and calcium phosphate (MSCNs) with pH-triggered chemotherapeutic release and dual-targeting functions. By decorating the nanoparticle surface with a transferrin (Tf)/RGD ligand, these nanoparticles are capable of not only recognizing the intrinsic pH difference between tumor and normal tissues, but also targeting the lesion location. It was shown that Tf/RGD-MSCNs delivered the anti-tumor drug doxorubicin more efficiently into lysosomes and the resulting DOX-loaded nanoparticles (DOX-Tf/RGD-MSCNs) showed a stronger inhibitory effect towards tumor cell growth than free DOX and DOX delivered by unmodified MSNs. Moreover, the nanoparticles are more biocompatible than uncoated mesoporous silica nanoparticles. All these results indicate that Tf/RGD-MSCNs have great potential as a novel drug carrier in therapeutic applications against cancers.

3D Architectured Poly(acrylamide-co-azomethine-co-acrylic acid) Cogel: Synthesis, Characterization and Salinity Profile

Herein, this innovative work; Poly(acrylamide-co-azomethine-co-acrylic acid) cogel is prepared in water as green solvent in order to study the effect of acrylamide content on swelling behaviour of hydrogels. It is found that hydrogels prepared in solution exhibited the highest swelling which probably extend it’s use in agricultural filed as well as in marine industry. The hydrogels is characterized by fourier transform infrared, elemental analysis, differential scanning calorimetry, thermal gravimetric analysis and field emission scanning electron microscopy. From Morphology study, we can see the change in porosity of cogel which is responsible for the absorbance of cogel. The results also indicated that the stability of azomethine is increased by formation of co-gel with poly(acrylamide–co-acrylic acid). In this report, straight forward and efficient synthetic protocol for cogel formation is adopted without any environmental hazard. Swelling capacity of P(AM-co-AA) and cogel was studied by addition of different saline solutions including monovalent, divalent, and trivalent salts. Its applications can be extended in agricultural industries as a basis for super absorbent polymer, waste water treatment, and even in medical field. Hence, the synthesized materials can be biodegradable, environment-friendly, and biocompatible inspired by the green

Characterization and swelling properties of copolymer Poly(N, N-dimethyl acrylamide -co-acrylic acid) and homopolymer Poly (acrylic acid)

This paper investigates the swelling properties of homopolymer and copolymer hydrogels. Copolymeric hydrogels based on N, N-dimethyl acrylamide and acrylic acid (poly(DMA-co-AAc) as well as homopolymer hydrogels based on acrylic acid (polyAAc) were synthesized by radical technique in aqueous solutions using ammonium persulfate as an initiator and N, N-methylene-bis-acrylamide as a crosslinking agent. The properties of hydrogels examined including scanning electron microscopy (SEM) and FT-IR. The results indicate that the poly(DMA-co-AAc) copolymer has a high swelling ability in an aqueous solution. The swelling of hydrogels were achieved a maximum degree and diameter of 270 and 63mm in water, respectively. The swelling behavior of these hydrogels was investigated to determine function of the effect of pH and polymeric compositions.

Dual (thermo-/pH-) responsive P(NIPAM-co-AA-co-HEMA) nanocapsules for controlled release of 5-fluorouracil

Dual-responsive nanocapsules of poly (N-isopropyl acrylamide (NIPAM)-co-acrylic acid (AA)-co-2-hydroxyethylmethacrylate (HEMA)) were synthesized by precipitation polymerization. The dual (temperature- and pH-)-responsive nanocapsules were fabricated using NIPAM as a temperature-sensitive monomer, AA as a pH-responsive monomer and 5-fluorouracil (5-FU) as a model drug. The P(NIPAM-co-AA-co-HEMA) nanocarrier had a hollow nanocapsule structure with average diameter of about 70 nm and a shell thickness of about 10 nm. The nanocarrier exhibited good loading capacity (32.6%) and considerable encapsulation efficiency (57.3%) for 5-FU by physical entrapment. The zeta potentials of nanocapsules were observed from −30.7 to −35.2 mV after the incorporation of 5-FU. The cumulative release of nanocapsules reached at 88.7% (37 °C, pH 5.8). The overall drug release performance revealed that the drug release behavior was efficient, sustainable and stable at 37 °C and pH 7.4. In addition, the release mechanism analysis suggested that the drug release behavior is more dependent on pH than temperature.

Synthesis of a novel amphoteric copolymer and its application as a dispersant for coal water slurry preparation.

In this work, a novel amphoteric copolymer named Poly(sodium p-styrenesulfonate–co-acrylic acid-co-diallyldimethylammonium chloride) (P(SS-co-AA-co-DMDAAC)) was synthesized via free radical polymerization. Afterwards, P(SS-co-AA-co-DMDAAC) was explored for use as a dispersant in coal water slurry (CWS) preparation. The structure of P(SS-co-AA-co-DMDAAC) was verified by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The synthetic conditions were optimized as the feed ratio of AA to SS was 1 : 1 (for Yulin coal) or 1.5 : 1 (for Yili coal), and DMDAAC dosage was 4.0 wt% (for Yulin coal) and 6.0 wt% (for Yili coal) toward total monomers. The performances of P(SS-co-AA-co-DMDAAC) as a dispersant for CWS were evaluated by various technologies, such as apparent viscosity, zeta potential, static stability and contact angle measurements. The results revealed that the optimized dosage of P(SS-co-AA-co-DMDAAC) in CWS preparation was 0.3 and 0.4 wt% for Yulin coal and Yili coal respectively. In this optimum condition, CWS prepared using P(SS-co-AA-co-DMDAAC) as dispersant showed a typical shear thinning behaviour and excellent stability, which are desired in industries. The rheological models also confirmed the pseudo-plastic characteristics of CWS. Finally, compared with the widely used anionic dispersant naphthalene sulphonate formaldehyde condensate (NSF) and poly(sodium p-styrenesulfonate) (PSS), P(SS-co-AA-co-DMDAAC) developed in this work exhibited better slurry making performance. The introduction of cationic functional groups promoted the adsorption of the dispersant, which further enhanced the electrostatic repulsion and steric hindrance among coal particles. Accordingly, the viscosity of CWS decreased and static stability enhanced.

Mesoporous hollow hydroxyapatite capped with smart polymer for multi-stimuli remotely controlled drug delivery

Abstract In this paper, a pH-/thermal-/NIR multi-responsive drug delivery platform based on hollow hydroxyapatite (H-HAP), poly(N-isopropylacrylamide- co-acrylic acid) (PNA) and gold nanorods (AuNRs) were prepared via electrostatic self-assembly. Thermal-sensitive PNA and near-infrared (NIR) responsive AuNRs were capped on the surface of mesoporous hollow HAP to obstruct the initial burst release of HAP and endow the vehicles with multi-responsive drug delivery properties. Notable pH-/thermal-/NIR multi-responsive drug release properties were clearly observed for H-HAP/PNA/AuNRs hybrid microcapsules. In addition, relatively high DOX release could be found for H-HAP/PNA/AuNRs hybrid microcapsules at pH 4.5 upon NIR laser irradiation, due to the corrosion of H-HAP in acidic media and the synergistically photothermal effect between AuNRs and PNA. This study provides a feasible method to fabricate intelligently controllable hybrid drug carriers, which shows great potential in controllable drug delivery.

Purification of low-abundance lysozyme in egg white via free-flow electrophoresis with gel-filtration chromatography.

As an effective separation tool, free-flow electrophoresis has not been used for purification of low-abundance protein in complex sample matrix. Herein, lysozyme in complex egg white matrix was chosen as the model protein for demonstrating the purification of low-content peptide via an FFE coupled with gel fitration chromatography (GFC). The crude lysozyme in egg while was first separated via free-flow zone electrophoresis (FFZE). After that, the fractions with lysozyme activity were condensed via lyophilization. Thereafter, the condensed fractions were further purified via a GFC of Sephadex G50. In all of the experiments, a special poly(acrylamide- co-acrylic acid) (P(AM-co-AA)) gel electrophoresis and a mass spectrometry were used for identification of lysozyme. The conditions of FFZE were optimized as follows: 130 μL/min sample flow rate, 4.9mL/min background buffer of 20mM pH 5.5 Tris-Acetic acid, 350V, and 14°C as well as 2mg/mL protein content of crude sample. It was found that the purified lysozyme had the purity of 80% and high activity as compared with its crude sample with only 1.4% content and undetectable activity. The recoveries in the first and second separative steps were 65% and 82%, respectively, and the total recovery was about 53.3%. The reasons of low recovery might be induced by diffusion of lysozyme out off P(AM-co-AA) gel and co-removing of high-abundance egg ovalbumin. All these results indicated FFE could be used as alternative tool for purification of target solute with low abundance.

HPMC-co-acrylic acid dexibuprofen once-daily oral hydrogels

The study aimed to synthesize dexibuprofen (DXIBN) solid dispersions (SDS)-loaded hydroxypropylmethylcellulose (HPMC) and co-acrylic acid (AA)-based oral hydrogels via a modest solvent evaporation technique. Free radical polymerization technique was used to prepare HPMC-co-AA hydrogels using EGDMA as cross-linker and ammonium per sulfate as initiator. SDS of DXIBN were prepared using Soluplus® (SLPS®) as a solubilizing agent. The solubility of pure DXIBN and the respective SDS was analyzed in phosphate buffer solutions (PBS) at varying pH (1.2, 6.8 and 7.4 pH) at temperatures (25 and 37 °C). The physiochemical characterizations: swelling analysis, diffusion co-efficient, porosity and sol-gel analysis, Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC), swelling behavior and release studies (at pH 1.2 and 7.4) were steered. The solubility was found to be significantly (p < .05) improved up to twofolds as compared to pure DXIBN. The hydrogels with higher concentrations of HPMC and AA showed significant (p < .05) increase in swelling, whereas there was a significant (p < .05) decrease with higher concentration of cross-linker EGDMA. The release kinetics applied trailed overall the non-Fickian release mechanism. The existing work exhibited was found to be improved DXIBN solubility using Soluplus via SDS technique and a stable HPMC-co-AA DXIBN release retardant hydrogel as an exceptional safer tool for the treatment of rheumatoid arthritis.

Microgel-Based Stretchable Reservoir Devices for Elongation Enhanced Small Molecule Release Rate.

Stretchable poly(N-isopropylacrylamide)-co-acrylic acid (pNIPAm-co-10% AAc) microgel-based reservoir devices were fabricated and used to control the release rate of the small molecule model drug tris(4-(dimethylamino)phenyl)methylium chloride (crystal violet, CV) to solution by varying the Au layer thickness coating the microgels and device elongation. Specifically, we showed that CV could be loaded into the microgel layer of the devices via electrostatic interactions at pH 6.5, and the release could be triggered upon exposure to a pH 3.0 solution, which breaks the microgel-CV electrostatic interactions. We demonstrated that the rate of release could be increased by decreasing the Au layer thickness coating microgels and by stretching, that is, thin Au and high elongation promoted the relatively fast release of CV from the device. We found that the Au overlayer thickness (and porosity) dominated the observed release rate profiles when the device was not stretched (or at low elongation), while elongation-induced cracks dominated the release rate at high elongation. We also showed that the CV release kinetics could transition from low ("off") to high ("on"), which enhanced when the devices are stretched. This behavior could be exploited in the future for autonomous release systems that release small molecules when stretched by natural processes, for example, movement of joints and muscles.

Poly(acrylamide-co-acrylic acid) gel polymer electrolyte incorporating with water-soluble sodium sulfide salt for quasi-solid-state quantum dot-sensitized solar cell

Rapid decay of photoanode, leakage from sealant, and evaporation of electrolyte are always the major concerns of quantum dot-sensitized solar cells (QDSCs) based on liquid electrolyte. Subsequently, gel polymer electrolyte (GPE) appears as an attractive solution in addition to lower cost, lighter weight, and flexibility. Poly(acrylamide- co-acrylic acid) (PAAm-PAA) is of special interest to act as a polymer host to entrap liquid electrolyte because it provides high transparency, good gelatinizing properties, and excellent compatibility with the liquid electrolyte. In this work, the electrical and transport properties of PAAm-PAA GPE incorporating with water-soluble sodium sulfide were characterized by impedance spectroscopy. An increment of ionic conductivity was observed with the incorporation of ethylene carbonate (EC) and potassium chloride (KCl). The highest room temperature ionic conductivity of PAAm-PAA GPE is 70.82 mS·cm−1. QDSC based on PAAm-PAA GPE with the composition of 1.3 wt% of KCl, 0.9 wt% of EC, 55.3 wt% of PAAm-PAA, 38.5 wt% of sodium sulfide, and 4.0 wt% of sulfur can present up to 1.80% of light-to-electricity conversion efficiency.

Deswelling studies of pH and temperature-sensitive ultra-low cross-linked microgels with cross-linked cores

Microgels prepared without exogenous crosslinker have recently been explored for diverse applications in biotechnology. However, our fundamental understanding of structure-property relationships for this class of materials is still lacking, especially in the context of more complex structures such as core-shell particles. In this article, core-shell microgels were prepared by seed-mediated, surfactant-free emulsion polymerization using a N,N′-methylenebis (acrylamide) (BIS) cross-linked poly(N-isopropylacrylamide) (pNIPAm) microgel core upon which a crosslinker-free poly(N-isopropylacrylamide)-co-acrylic acid (ULC10AAc) shell was synthesized. Dynamic light scattering (DLS) and phase analysis light scattering (PALS) measurements show that the hydrodynamic radius and electrophoretic mobility of the core-shell microgels increase significantly with increasing pH due to the pH responsive ULC10AAc shell, while the temperature sensitivity of the microgels is also strongly pH dependent. The turbidity and the temperature-dependent scattering intensity plots of microgels at different pH also provide insight into the charged state of the microgels under the studied conditions. For example, we observe multiple temperature-induced transitions when the pH is either 4.5 or 6.5, illustrating that the core and shell domains, while remaining mechanically connected, are only partially coupled thermodynamically. These studies provide insight into the perturbation of ULC microgel behavior that might be brought about due to the presence of a higher density core region. Complex architectures such as these are relevant in biotechnology applications where the soft, deformable ULC shell is advantageous to control the polymer-biology interface, but a denser core region might be required to obtain a higher loading of encapsulated therapeutics, tracking dyes, or oligonucleotides. Thus, it is important to understand the synthetic conditions that allow a ULC shell to remain “ULC-like” despite the presence of a denser core.

A multifunctional antifog, antifrost, and self-cleaning zwitterionic polymer coating based on poly(SBMA-co-AA)

In this work, a multifunctional coating was developed by grafting a zwitterionic poly[2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)-co-acrylic acid [poly(SBMA-co-AA)] polymer onto a glass slide, which possesses excellent antifog, antifrost, and self-cleaning properties. These properties are attributed to the strong hydration of the hydrophilic zwitterionic PSBMA segments. The durability of the coating can be improved because the carboxyl group (–COOH) of the PAA segment enables formation of a robust covalent bond with the amino group (–NH2) on the substrate. The coating presents long-term stability, as proved by water contact angles, which were stable at 12 ± 1° after exposing the coating in ambient environment for 60 days or immersing in deionized water for 24 h. In addition, the underwater oil contact angle measurement demonstrated that an oil stain on the zwitterionic poly(SBMA-co-AA) polymer coating can be easily removed upon contact with water, showing self-cleaning performance. These properties verified that the zwitterionic multifunctional coating exploited in this research has many potential application prospects, including construction, automotive, aerospace, shipbuilding, biomedical, and other optical fields.

Morphology Control of Liposome - RAFT Oligomer Precursors to Complex Polymer Nanostructures.

Different types of butyl acrylate (BA)-co-acrylic acid (AA) oligomers were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization and mixed with extruded 200 nm dimethyldioctadecylammonium bromide vesicles. The resulting precursor structures form the basis for subsequent vesicle-templated polymerizations. Systematic variations in temperature, pH, oligomer length, and oligomer composition and their effects on precursor morphology were studied. Surprisingly, different morphologies were obtained, including capsules, protruded capsules, solid spheres, and multicompartment structures. For example, capsules and multicompartment structures were found to result from higher AA contents, and protruded capsules and solid particles resulted from lower AA contents. Subsequent chain extension of the RAFT oligomers resulted in polymer nanostructures resembling the precursor morphologies.