Hydrophilic Monomers Research Articles

Anionic amphiphilic copolymers as potential agents for enhanced oil recovery

To develop “smart fluids” for enhanced oil recovery from reservoir rocks, comb-type amphiphilic copolymers were synthesized through free radical polymerization (FRP) of: (i) the hydrophilic, anionic monomer 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA) that offer a hydrophilic character to the final copolymers; (ii) the weakly acidic hydrophilic monomer acrylic acid (AA); (iii) the hydrophobic monomer dodecyl methacrylate (DMA). The polymers were characterized by Proton Nuclear Magnetic Resonance (1H NMR), Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR), fluorescence probing, Dynamic Light Scattering (DLS) and electrophoresis. Stable polymer solutions were prepared without and with the presence of salts (NaCl, CaCl2, MgSO4). The dynamic air/water surface and oil/water interfacial tensions were measured by the pendant drop method, and their steady-state values were estimated with fitting to asymptotic relations predicting the long-time behavior. Moreover, the wettability of water/air and water/oil to glass or poly(methyl methacrylate) (PMMA) surface was quantified by measuring the contact angles. Oil-in-water Pickering emulsions were prepared by mixing n-dodecane with polymer solutions and their stability was evaluated macroscopically with optical inspection, and microscopically by measuring the oil drop size distribution and shear viscosity. Polymer solutions and Pickering emulsions were tested as agents for the displacement of the residual n-dodecane from a glass-etched pore network. The long-lasting retention of polymer solution in the pore network makes the solid surface more hydrophilic, facilitating the fission of oil ganglia into smaller ones which are mobilized easier, resulting in a final EOR efficiency between 10% and 18%. When using an emulsion as displacing fluid, the viscosity ratio and capillary number increase by orders of magnitude, the viscous forces prevail against the capillary ones, and the growth pattern becomes a frontal drive leading to a high EOR efficiency of ∼94%.

Micelle‐crosslinked hydrogels with stretchable, self‐healing, and selectively adhesive properties: Random copolymers work as dynamic yet self‐sorting domains

AbstractThe design of crosslinking domains is a vital factor to create functional hydrogels with controlled physical, mechanical, and adhesive properties. This paper demonstrates versatile synthetic systems of micelle‐crosslinked hydrogels with highly stretchable, self‐healing, and selectively adhesive properties. For this, methacrylate‐bearing random copolymer micelles are designed as physical and covalent crosslink domains via the self‐assembly of amphiphilic random copolymers carrying hydrophilic poly(ethylene glycol) (PEG), hydrophobic butyl or dodecyl groups, and methacrylate‐terminal PEG in water. The size, aggregation number, and pendant methacrylate number of the micelles are controlled by the composition and degree of polymerization. Hydrogels are efficiently obtained from the free radical polymerization of hydrophilic monomers such as PEG acrylate and acrylamide in the presence of the micelle crosslinkers in water. Owing to the dynamic yet selective chain exchange properties of the micelle domains, the hydrogels are highly stretchable up to over 1000% and show self‐healing and selectively adhesive properties. The self‐healing of hydrogels is promoted upon heating due to the fast chain exchange of the micelle domains, whereas hydrogels consisting of micelles with different alkyl groups are never adhesive because of their self‐sorting properties.

Shape-Tunable Biconcave Disc-Like Polymer Particles by Swelling-Induced Phase Separation of Seeded Particles with Hydrophilic Shells.

Anisotropic shape-tunable polymer particles have gained significant attention for their wide applications, and their performances are usually strongly correlated to their shapes. In contrast to convex particles, the synthesis of highly uniform concave polymer particles remains a great challenge. Here, we present a facile and effective route to synthesize biconcave polystyrene (PS) discs by swelling-induced phase separation of hydrophilically modified PS microspheres and report an unexpected finding that even a tiny amount of hydrophilic units that were incorporated into PS microspheres can significantly change the shape of phase interfaces, resulting in the transformation of disc shapes from convex to flat to concave. This is realized by several typical hydrophilic monomers, such as sodium styrene sulfonate (NaSS), acrylic acid (AA), or (2-(methacryloyloxy)ethyl)trimethylammonium chloride (METAC). The effect of the distribution of hydrophilic units in microspheres was investigated, and the mechanism of shape tuning has been discussed. The curvatures of the bottom surfaces of discs show a strong correlation to the content of hydrophilic units. In particular, we emphasize that the shape control method is general since it does not depend on specific hydrophilic units. This research paves the way for precisely structuring polymer particle shapes, which is important for polymer particles to be used for self-assembly, diffusion, rheology, transport, filler, and many other applications.

Thermo/β-cyclodextrin-responsive ferrocenyl hydrogels constructed by ROMP reaction

Hydrogels with stimuli-responsive behavior have been of great interest to researchers from many fields, such as biotechnology, drug delivery, and sensors, owing to their “smart” change in properties under external stimuli such as temperature, pH, pressure, redox, magnetic and electric fields. In this work, using the third generation Grubbs’ catalyst as the initiator, both temperature and β-cyclodextrin (β-CD) stimuli-responsive ferrocenyl hydrogels were prepared with different proportions of hydrophilic norbornene monomer NTEG, ferrocene-containing monomer NFc and crosslinker 1 by using one-pot ROMP (ring-opening metathesis polymerization) reaction. Based on the mechanical and rheological tests, it was found that NFc not only played a crucial role in maintaining the structure of ferrocenyl hydrogels, but also enhanced their physical strength. Comparatively, the increase of the NTEG content in the hydrogel system can improve the toughness of the resulting hydrogels. Furthermore, Results of the swelling ratio test demonstrated that these hydrogels possessed temperature-responsiveness, in which the NTEG block, which contained dendritic oligoethylene glycol structures in the side chain, played a decisive role. Simultaneously, it is worth noting that these ferrocenyl hydrogels also exhibited responsive behavior to β-CD solution due to the host-guest interaction of ferrocene unit with β-CD macromolecule. Therefore, we believe that this study provides a new idea for the design of covalently crosslinked ferrocenyl stimuli-responsive smart hydrogels.

Efficient synthesis of superabsorbent beads using photopolymerization with a low-cost method

Superabsorbent polymers are widely used in hygiene, agriculture, and contamination removal products. The preparation of superabsorbent beads has been reported in the literature from thermal and photopolymerizations of hydrophilic monomers. The rate of photopolymerization is normally faster than thermal polymerization. Our study aimed to test whether the fast photopolymerization technique would work with cheap, easily accessible monomers, and simple equipment that is affordable to high school students within a typical chemistry lab setting. We also evaluated the water absorbance of polymers prepared from hydrophilic monomers. We chose two hydrophilic monomers, N,N’-dimethylacrylamide (DMAA) and N-hydroxyethyl acrylamide (HEAA), and employed LED UV/Vis light as the light source to break photoinitiator molecules, with silicone oil as the polymerization medium. We hypothesized that superabsorbent beads could be prepared from DMAA and HEAA using the fast photopolymerization technique at room temperature using silicone oil. Our experiments demonstrated the synthesis of superabsorbent beads from a mixture of DMAA, HEAA, and photoinitiator in 60 seconds at ambient conditions. We also discovered that water absorbance increased with the increase of DMAA when its concentration was equal to or less than 25% by weight in the monomer mixture. Beads were completely soluble in water when the concentration of DMAA was equal to or over 50% by weight. Beads with a 25:75 DMAA:HEAA weight ratio demonstrated the highest efficiency among the six compositions tested. Our research also paves the way for high school students to investigate advanced polymerizations in a very simple way.

Biocompatible polymers with tunable mechanical properties and conductive functionality on two-photon 3D printing.

Two-photon polymerization (TPP)-based 3D printing technology utilizes the two-photon absorption process of near-infrared radiation, enabling the fabrication of micro- and nano-scale three-dimensional structures with extremely high resolution. It has been widely applied in scientific fields closely related to living organisms, such as tissue engineering, drug delivery, and biosensors. Nevertheless, the existing photoresist materials have poor mechanical tunability and are hardly able to be doped with functional materials, resulting in constraints on the preparation of functional devices with micro-nano structures. In this paper, TPP printable polymer formulas with good mechanical tunability, high resolution, strong functional scalability, and excellent biocompatibility are proposed, by using the synergistic effects of a hydroxyl group-containing photocurable resin prepolymer, UV acrylate monomer, long-chain hydrophilic crosslinking monomer and photo-initiator. This can ensure the printability and help to improve the flexibility of the printed polymer, thereby solving the problem the photosensitive materials suitable for two-photon 3D printing in previous research had in balancing the formability and flexibility. The results of nanoindenter analysis showed that the Young's modulus of the printed structure can be adjusted between 0.3 GPa and 1.43 GPa, realizing mechanical tunability. Also, complex structures, such as micro-scaffold structures and high aspect ratio hollow microneedles were printed to explore the structural stability as well as the feasibility of biodevice application. Meanwhile, the proposed polymer formula can be functionalized to be conductive by doping with functional nanomaterial MXene. Finally, the biocompatibility of the proposed polymer formula was studied by culturing with human normal lung epithelial cells. The results indicated a good potential for biodevice applications.

Dual-reactive hydrogels functionalizable using "Huisgen click" and "Schiff base" reactions.

Hydrogels incorporating different reactive groups are important platforms for the fabrication of functional materials through the conjugation of diverse molecules. In this study, a dual-reactive hydrogel system was designed utilizing aldehyde and azide groups containing methacrylate monomers. Hydrogels were obtained in the presence of a dimethacrylate crosslinker with a combination of hydrophilic PEG-based monomers via free-radical polymerization. The azide and aldehyde sites of the hydrogel network are reactive towards alkyne and amine functional groups, respectively. The advantage of the different reactivities of these functional groups was demonstrated through the attachment of two different dye molecules onto the hydrogel platform via the "Huisgen click" and "Schiff base" reactions to obtain a sensing platform for various applications, such as indicating change in pH of the environment.

Ultra-stiff and tough hydrogels based on small but strong hydrophobic associations via a low-reactive hydrophilic monomer

Strong hydrophobic associations were formed between hydrophobic moiety-protected carbamate side groups of monomers, whose density and strength were regulated by using a low-reactive hydrophilic monomer to prepare ultra-stiff and tough hydrogels.

Higher Adhesion Strength Over 10 N/mm Between Rubber and Fluoropolymer Film When Treated by Atmospheric Plasma-Graft Polymerization

An evaluation of the adhesion between rubber and fluoropolymer films treated by atmospheric plasma-graft polymerization is conducted to realize a low-permeation fuel rubber hose covered with fluoropolymer. The low-permeation fuel rubber hose is important for reducing vehicular evaporative emissions. Although fluoropolymers have extremely low permeability for fuel, it is difficult to bond them with other materials, such as rubber, because of their low adhesive properties. Plasma surface modification has been investigated to improve the adhesive properties of fluoropolymers. However, it is difficult to realize effective and permanent surface treatment using plasma alone. Based on the new and effective combined plasma surface-modification technique for fluoropolymer films, we previously proposed an atmospheric-pressure plasma method followed by graft polymerization of hydrophilic monomers such as acrylic acid (CH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> = CHCOOH). In this study, three types of rubber, isobutylene isoprene rubber (IIR), ethylene acrylic elastomer (AEM), as well as white-colored ethylene acrylic elastomer (white AEM), and two types of fluoropolymer films, denatured PFA-1 and denatured PFA-2, were prepared. The treated fluoropolymer film and rubber were adhered using vulcanized adhesion, and then the 180° peeling strength test was conducted. The results show that an average peeling strength of 12.6 N/mm and a maximum peeling strength of 15.3 N/mm, which are over 10 N/mm, are attained for the sample of vulcanized bonding of the treated denatured PFA-1 and AEM.

Activity Improvement and Thermal Stability Enhancement of D-Aminoacylase Using Protein-Polymer Conjugates

In this study, the synthesis of new polymer-protein conjugates using a grafting-from strategy was performed by employing photo-induced electron transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization. D-aminoacylase is an industrially significant enzyme for the preparation of chiral amino acids and it is coupled with reversible addition-fragmentation (RAFT) chain transfer agent (CTA) using activated ester chemistry. The effects of polymeric side chain compositions on the activity of D-aminoacylase were studied with two different polymeric side chain lengths. For this reason, two monomers, a hydrophilic N-(2-aminoethyl acrylamide) and a hydrophobic and N- (iso-butoxymethyl) acrylamide were used, respectively. It was found that modification by grafting from strategy increased the thermal stability of D-aminoacylase enzyme. Additionally, the hydrophobic monomer conjugate has been reported to increase the activity of the enzyme more than the hydrophilic monomer.

A novel polymeric nanocomposite based on TiO2 NPs containing β-cyclodextrin membrane for ultratrace naked-eye detection of Pb and Cd ions

A unique, selective, and sensitive colorimetric nanosensor for the naked-eye detection and adsorption of Pb(II) and Cd(II) in aqueous media has been synthesized based on the organic–inorganic hybrid. Acrylamide (AM) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as hydrophilic monomers, functionalized β-cyclodextrin (f-β-CD) as host-guest complex formation agent, and vinyl-dithizone (f-DTZ) as an efficient ligand were used. The β-CD with a hydrophobic interior and hydrophilic exterior can form a host-guest inclusion complex with a ligand that enhances nanosensors’ dispersion in aqueous media. The immediate color change of the sensor has been observed from gray to pink and blue for Pb(II) and Cd(II) with a wide linear range of [(1 ppb- 40 ppb)] and [(1 ppb- 60 ppb)], respectively. This study also considered the adsorption qualities of these heavy metals under various factors, including pH, time length, and initial ion concentration. The maximum adsorption capacity of Cd(II) via polymeric nanocomposite was 166 mg·g−1 at optimum condition. The experimental info has been investigated using the Langmuir and Freundlich isotherms and the pseudo-first-order and pseudo-second-order kinetic models.

Ferritin-Enhanced Direct MicroRNA Detection via Controlled Radical Polymerization

Accurate quantitative detection of tracing nucleic acids remains a great challenge in cancer genetic testing. It is crucial to propose a low-cost and highly sensitive direct gene detection method for cancer prevention and treatment. Herein, this work reports an ultrasensitive biosensor via a ferritin-enhanced atom-transfer radical polymerization (Ft-ATRP) process. Intriguingly, microRNA-21, an early marker of lung cancer, can be detected without being transcribed in advance by an innovative signal amplification strategy using ferritin-mediated aggregation of hydrophilic nitroxide radical monomers as an electrochemical biosensor. The sensor uses peptide nucleic acid probes modified on a gold electrode to accurately bind the target lung cancer marker in the sample, and then ferritin, which is naturally present in human blood, induces Ft-ATRP on the electrode surface under mild conditions. Many of 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (MATMP) monomers with electrochemical signals are combined into polymeric chains to be modified on target assays. The limit of detection (LOD) of microRNA-21 is as low as 6.03 fM, and the detection concentration ranges from 0.01 to 100 pM (R2 = 0.994). The RNA biosensor can realize great performance analysis of complicated samples in simple operation, in addition, the detection process used by the catalyst, polymers containing electrochemical signals, and the electrolyte solution all have good water solubility. The superior performance of the RNA biosensor demonstrates its potential to screen and identify lung cancer in target patients.

Universal Character of Breaking of Wormlike Surfactant Micelles by Additives of Different Hydrophobicity.

Wormlike surfactant micelles are widely used in various applications including fracturing technology in oil industry, template synthesis of different nanoobjects, micellar copolymerization of hydrophilic and hydrophobic monomers, and so forth. Most of those applications suggest the solubilization of different additives in the micelles. The present paper is aimed at the comparative study of the effect of the solubilization of hydrophobic (n-decane and 1-phenylhexane) and hydrophilic (N-isopropylacrylamide and acrylamide) substances on the rheological properties and structure of the micelles using several complementary techniques including rheometry, small angle neutron scattering, dynamic light scattering, and diffusion ordered NMR spectroscopy. For these studies, mixed micelles of potassium oleate and n-octyltrimethylammonium bromide containing the excess of either anionic or cationic surfactants were used. It was shown that hydrophobic additives are completely solubilized inside the micelles being localized deep in the core (n-decane, 1-phenylhexane) or near the core/corona interface (1-phenylhexane). At the same time, only a small fraction of hydrophilic additives (14% of N-isopropylacrylamide and 4% of acrylamide) penetrate the micelles being localized at the corona area. Despite different localization of the additives inside the micelles, all of them induce the breaking of wormlike micelles with the formation of either ellipsoidal microemulsion droplets (in the case of hydrophobic additives) or ellipsoidal surfactant micelles (in the case of hydrophilic additives). The breaking of micelles results in the drop of viscosity of the solution up to water value. The main result of this paper consists in the observation of the fact that for all the additives under study, the dependences of the viscosity on the volume fraction of additive lie on the same master curve being shifted along the volume fraction axis by a certain factor depending on the hydrophobicity of the added species. Those data are quite useful for various applications of wormlike surfactant micelles suggesting the solubilization of different additives inside them.

Simultaneously Enhancing the Mechanical Strength and Ionic Conductivity of Stretchable Ionogels Enabled by Polymerization-Induced Phase Separation

Stretchable ionogels have been considered as ideal materials for constructing flexible electronics. However, current ionogels suffer from the well-known trade-off between mechanical strength and conductivity. Here, we develop a simple strategy based on polymerization-induced phase separation to simultaneously enhance the mechanical performance and conductivity of the ionogels by randomly copolymerizing a hydrophobic and a hydrophilic monomer in a hydrophobic ionic liquid (IL). The polymerization process induced the formation of a bicontinuous network containing a polymer-rich phase and a solvent-rich phase. The polymer-rich domains with hydrogen bonds can bear loading, greatly improving the mechanical strength; meanwhile, the solvent-rich domains form conductive nanochannels to enhance the conductivity. The resulting copolymer ionogel is highly stretchable (500% strain), and the optimal fracture stress and conductivity are 0.29 MPa and 3.4 mS/cm, achieving 7.8- and 2.3-fold enhancements compared with that of the prepared homogeneous (pure PMEA) ionogel at the same IL content, respectively. Moreover, the ionogels also exhibit anti-swelling properties in various liquids and self-adhesiveness. Potential applications of this ionogel as a wearable sensor in a complex environment are further demonstrated.

Polyacrylic Acid Copolymers as Adhesion‐Adapted Model Materials for Cleaning Tests

AbstractFor cleaning tests, which are important in many industrial processes, there are no test contaminations with which geometry‐independent homogeneous films can be produced. Polymer films can fill this gap when they are able to mimic the properties of reference contaminants. For this purpose, acrylic acid (AA) copolymers are prepared by conventional atom transfer radical copolymerization and subsequent acidolysis of the tert‐butyl acrylate (tBA) prepolymers. In this way polarity and adhesion can be adjusted by the amount of carboxy groups in the polymer. Dynamic contact angle measurements show that the advancing contact angle of acrylic acid/methyl(meth)acrylate statistical copolymer layers increase with decreasing carboxy group content. Cleaning experiments show accordingly that the amount of residual polymer of coatings made from these polymers is dependent on the absolute number of adhesive carboxy groups in the polymer. Therefore, for an adaption of the polymer layers to hydrophilic reference contaminants it is necessary to incorporate additional hydrophilic monomer components into the polymers, which lead to lower contact angles but also stronger adhesion of the layers. Hence, it is shown that the chosen polymer concept is delivering the leverages to adjust the properties of appropriate test contaminants.

Effect of Collagen-Reactive Functional Monomer on Etch-and-Rinse Adhesives

In this study, we evaluated a novel functional monomer (4-formylphenyl acrylate [FA]) that can specifically and covalently bind to the dentin collagen matrix as a potential alternative hydrophobic diluent-like monomer for improving the durability of dentin bonding. Experimental adhesives with different FA contents (0%, 10%, 20%, and 30%) were evaluated as partial substituents for the hydrophilic monomer 2-hydroxyethyl methacrylate, with the commercial adhesive One-Step (Bisco, Inc.) employed as the positive control. Their degree of conversion, viscosity, hydrophobicity, mechanical properties, and water absorption/solubility were measured as the comprehensive characterization. In situ zymographic assays were performed to determine the extent to which FA inhibits the endogenous hydrolytic activity of dentin. Finally, the bonding performances of the novel adhesives were evaluated with microtensile strength tests and scanning electron microscopy. The results showed that the incorporation of FA significantly improved the mobility of experimental adhesives attributable to the dilution property of FA. In contrast to the possible compromised rate of polymerization by hydroxyethyl methacrylate, FA exhibited typical characteristics of favorable copolymerization with polymerizable monomers in adhesives and improved the degree of conversion of experimental adhesives. The rigidity and hydrophobic properties of the phenyl framework of the FA molecule conferred superior mechanical properties and hydrolysis resistance to the novel experimental adhesives. An inhibitory effect on gelatinolytic activities within the hybrid layer was also observed in the in situ zymographic assays, even at a low FA concentration (10%). In conjunction with the significantly improved infiltration found via scanning electron microscopy, the experimental adhesives containing FA possessed significantly better-maintained microtensile strength, even after aging. Thus, the incorporation of this novel monomer endowed the experimental adhesives with multiple enhanced functionalities. These remarkable advantages highlight the suitability of the monomer for further applications in clinical practice.

Thermo/hydration responsive shape memory polymers with enhanced hydrophilicity for biomedical applications

Thiol-ene/acrylate shape memory polymers (SMPs) have sufficient stiffness for facile insertion and precision placement and soften after exposure to physiological conditions to reduce the mechanical mismatch with body tissue. As a result, they have demonstrated excellent potential as substrates for various flexible bioelectronic devices, such as cochlear implants, nerve cuffs, cortical probes, plexus blankets, and spinal cord stimulators. To enhance the shape recovery properties and softening effect of SMPs under physiological conditions, we designed and implemented a new class of SMPs as bioelectronics substrates. In detail, we introduced dopamine acrylamide (DAc) as a hydrophilic monomer into a current thiol-ene polymer network. Dry and soaked dynamic mechanical analyses were performed to evaluate the thermomechanical properties, softening kinetics under wet conditions, and shape recovery properties. Modification of SMPs by DAc provided an improved softening effect and shape recovery speed under physiological conditions. Here, we report a new strategy for designing SMPs with enhanced shape recovery properties and lower moduli than previously reported SMPs under physiological conditions without sacrificing stiffness at room temperature by introducing a hydrophilic monomer.

Development of temperature-responsive suspension stabilizer and its application in cementing slurry system

To solve the problem of cement slurry suspension instability caused by a geothermal gradient in low-pressure and leakage formation, a hydrophobically associating long-chain polymer (PSAN) was designed as a suspension stabilizer by introducing hydrophilic monomer acrylamide (AM), temperature-resistant monomer 2-acrylamide-2-methyl propane sulfonic acid (AMPS), hydrophobic monomer styrene (St) and temperature-sensitive monomer N-vinyl caprolactam (NVCL). The synthesis conditions of PSAN were optimized by orthogonal response surface method. The structure and performance of PSAN were characterized and tested by IR, 1H NMR, GPC, SEM, TG, high-temperature rheology, and fluorescent probes. The research and analysis showed that PSAN had a good temperature response. At 30–65 ℃, the apparent viscosity of PSAN aqueous solution increased with the increase of temperature. At 65 ℃, the hydrophobically associating ability of PSAN was enhanced, and the retention rate of the apparent viscosity of its aqueous solution at 65–110 ℃ was still more than 83%. The good temperature response of PSAN was conducive to the suspension stability of cement slurry under the condition of large temperature differences. When 1% bwoc (percentage of cement mass) was added to the cement slurry, the free liquid of the cement slurry was 0, the water loss was less than 90 mL, and the density difference between the upper and lower sections of the cement stone column was less than 0.01 g/cm3. SEM analysis showed that there was a network structure formed by hydrophobic association between PSAN molecules in cement. In a word, under the condition of 30–110 ℃ (80 ℃ large temperature difference), the suspension stabilizer PSAN can effectively alleviate the floating of light materials and the sinking of heavy materials in cementing slurry through the hydrophobic association between molecules, and ensure the suspension stability of cementing slurry, thus contributing to the safety of cementing construction and improving the quality of cementing.

Synthesis of Polymer Electrolyte Membranes from Sulfonated Poly(Arylene Ether Ketones) with Partial Substitution of Carboxylate Acid Group

AbstractChemical modification of Sulfonated poly(arylene ether ketone) with carboxylate acid side chain (C‐SPAEK) membranes has been conducted through partially substitution of the 4,4‐bis(4‐hydroxyphenyl)‐valeric acid (DPA) with 4,4‐bis(4‐hydroxyphenyl)‐propane (BPA) at varies different compositions of sulfonate. FTIR and EDS analysis of the synthesized SPAEK revealed the presence of carboxylic acid, methyl, sulfonate groups and aromatic ether bonds in the SPAEK membrane. The effect of different compositions of carboxylic acid and sulfonate groups on mechanical strength, thermal stability, oxidative stability, water absorption, swelling ratio and proton conductivity of the membranes was studied. The SPAEK‐50/50 membrane exhibits superior properties with high mechanical strength, high thermal and oxidative stability, good water absorption, low swelling ratio, high dimensional stability and has a proton conductivity at 80 °C of 0.102 S/cm close to the Nafion‐117 membrane of 0.120 S/cm. This finding confirms that the partial substitution of the hydrophilic monomer of DPA with 50 % mole of BPA with a sulfonate group composition of 50 % resulted in an excellent SPAEK membrane.

Influence of Hydrophobic Side-Chain Length in Amphiphilic Gradient Copoly(2-oxazoline)s on the Therapeutics Loading, Stability, Cellular Uptake and Pharmacokinetics of Nano-Formulation with Curcumin.

Due to the simple one-step preparation method and a promising application in biomedical research, amphiphilic gradient copoly(2-oxazoline)s are gaining more and more interest compared to their analogous block copolymers. In this work, the curcumin solubilization ability was tested for a series of amphiphilic gradient copoly(2-oxazoline)s with different lengths of hydrophobic side-chains, consisting of 2-ethyl-2-oxazoline as a hydrophilic monomer and 2-(4-alkyloxyphenyl)-2-oxazoline as a hydrophobic monomer. It is shown that the length of the hydrophobic side-chain in the copolymers plays a crucial role in the loading of curcumin onto the self-assembled nanoparticles. The kinetic stability of self-assembled nanoparticles studied using FRET shows a link between their integrity and cellular uptake in human glioblastoma cells. The present study demonstrates how minor changes in the molecular structure of gradient copoly(2-oxazoline)s can lead to significant differences in the loading, stability, cytotoxicity, cellular uptake, and pharmacokinetics of nano-formulations containing curcumin. The obtained results on the behavior of the complex of gradient copoly(2-oxazoline)s and curcumin may contribute to the development of effective next-generation polymeric nanostructures for biomedical applications.