Reactive & Functional Polymers最新文献

The present study perused the physicochemical, mechanical, thermal, barrier, and optical properties of pea protein isolate (PPI)-Sage seed gum (SG) (3:1, 1:1, and 1:3) composite films incorporated with cuminum essential oil (CEO, 0, 1, and 2 %). Results indicated that the thickness, contact angle (CA), yellowness index (a*), total color differences (∆E), and opacity (OP) significantly enhanced with increasing PPI portion and CEO concentration (p < 0.05), as well as heterogeneous and inconsistent structure were increased in film surface due to protein agglomeration and oil droplets. However, the moisture content (MC), water solubility (WS), and swelling ratio (SR) decreased. Results also indicated that the antioxidant property significantly increased (P < 0.05) following the increase in CEO concentration. The highest tensile strength (TS) and elastic modulus (EM) and the least elongation at break (EAB) in PPI 3-SG 1–0 % were estimated. The potential antimicrobial property of CEO containing film was confirmed, and the maximum inhibition zone for E.coli, S.aureus, C.albicans, and A.niger were measured in film containing 2 % CEO. The barrier properties of the film against water and oxygen (WVP, OXP) diminished with increases the SG ratios, due to the hydrophilic nature of SG. The FTIR analysis identified the functional groups in film components and the interaction between film components. The DSC thermogram indicated the thermal stability of films and the highest decomposition temperature in PPI 3-SG 1–2 % film. XRD revealed a semi-crystalline structure of biopolymer active films. With the increase of SG portion and CEO concentration, the crystallinity of the films was enhanced. Results also indicated that prepared films were more than 90 % biodegradable.

New type of diallyl bisphenol-A (ABA) based benzoxazines and benzoxazine resins tailored with epoxy groups for low-temperature curing, have been developed using various curatives for high performance applications. The molecular structure of the synthesized compounds was analyzed using HRMS, ¹H NMR, ¹³C NMR and ATR-FTIR analytical techniques. The cure behavior (T_p) of benzoxazine (Bz) and benz-epoxy (Bz-Ep) resin in the absence and presence of different nature of curatives were studied using DSC to evaluate their applicability for advanced composite applications. The values of T_p obtained are 279 °C, 190 °C and 247 °C for ABA-a, ABA-dmapa and ABA-ipa respectively. The cure behavior has been further lowered by converting ally group present in the benzoxazine has been transformed into epoxy groups by appropriate mechanism. The curing (T_p) temperature observed for hybrid ABA-a-Ep, ABA-dmapa-Ep and ABA-ipa-Ep benz-epoxy resins are 151 °C, 226 °C and 160 °C, 187 °C and 150 °C, 211 °C respectively. The T_p of different benz-epoxy resin systems studied in the presence of catalysts were found to be in the range of 101-155 °C. With a T_max of 484 °C and a char yield of 43 %, poly(ABA-a) exhibits impressive thermal stability when compared to other synthesized polybenzoxazines. Further, incorporating various curatives into the benz-epoxy matrix enhances its thermal stability and char yield compared to the neat matrices. Additionally, the developed samples exhibit excellent moisture resistant (0.75 %) and hydrophobic nature with the highest contact angle value of 152^o for poly(ABA-a). The findings from various studies indicate that the hybrid benz-epoxy resins demonstrate characteristics such as low-temperature curability, thermal stability, hydrophobicity. These results render them appropriate for a diverse array of high-performance industrial and engineering uses.

Polymer inclusion membranes (PIMs) exhibit great potential in the separation and recovery of valuable materials from wastewater and secondary resources. In this work, the effect of alkyl chain configuration of the functional carriers on the physicochemical properties and permeability of PIMs was investigated. Three tertiary amine isomers with different alkyl chain configurations were selected as carriers: trioctylamine, triisooctylamine, and tris(2-ethylhexyl)amine. Operating conditions like carrier contents, feed solution pH, phenol concentration, and stripping solution properties were also investigated. The results obtained in this study indicate that tertiary amines with less branched alkyl chains perform better phenol transport efficiency. Furthermore, the transport efficiency decreased rapidly with increasing steric hindrance of the carriers. Trioctylamine-based PIM displayed optimal extraction efficiency of 92.8 % and stripping efficiency of 90.8 % due to its lower steric hindrance, higher hydrophilicity, and larger crystallinity. Phenol extraction and stripping efficiencies remained above 85.7 % and 80.8 % after 8 cycles, demonstrating excellent stability.

Oral colon-targeted drug formulations play a pivotal role in managing colon diseases, yet the effectiveness of most hydrophobic drug formulations in reaching the colon orally is hindered by challenges such as poor solubility, premature release in the stomach, and low bioavailability. In this study, we devised a pH-sensitive dual-network hydrogel utilizing sodium alginate and methacrylic acid for treating ulcerative colitis. The primary rigid network layer is activated thermally through free radicals, while the secondary flexible network layer is formed by the coordination of alginic acid and calcium ions. Sulfadiazine was loaded into the hydrogels using a solution displacement method. We conducted a comprehensive analysis of the morphology, mechanical properties, and drug release mechanisms of the hydrogels. The hydrogel demonstrated outstanding pH-responsive swelling properties. In acidic environments, protonation of carboxyl groups led to hydrogel network contraction, while in weakly alkaline environments, deprotonation induced electrostatic repulsion, facilitating swelling and controlled drug release. The alteration of pH from 1.2 to 7.4 increased the drug release rate from 33 % to 92 %, aligning with the first-order kinetic release model. The drug-loaded gel exhibited a compressive stress of 0.13 MPa at 50 % strain, and its superior mechanical properties ensured stability before drug release. Moreover, the hydrogel displayed excellent biocompatibility, hemocompatibility, and thermal stability. In summary, these findings underscore the substantial potential of drug-loaded gels in advancing controlled drug delivery systems.

In this study, a chitosan/activated carbon composite was developed for the sustainable removal of dye pollutants from activated carbon derived from chitosan. First, chitosan was converted into chitosan-derived activated carbon (C-AC) with a large Brunauer-Emmett-Teller (BET) surface area of 2428 m²/g through carbonization using a potassium hydroxide (KOH) chemical activator. To enable simple separation from contaminated water and sustainable use in the adsorption process, the generated C-AC was incorporated into a bead-type, stable three-dimensional chitosan polymer network structure. The prepared C-AC-incorporated chitosan beads showed excellent adsorption capacity for the anionic acid orange 7 (AO) (511.38 mg/g) and the cationic methylene blue (MB) (413.08 mg/g). In addition, it maintained structural stability even in various pH environments and could be easily separated from contaminated water. The C-AC-incorporated chitosan beads showed excellent reusability and durability, maintaining at least 82% and 86% removal efficiencies for AO and MB dyes even after five reuses. This study suggests the potential use of chitosan as an eco-friendly adsorbent that can be utilized simultaneously as an activated carbon precursor and as a matrix for robust bead-like polymer composites.

In this study, a comprehensive structural analysis of the linear redox-active ferrocenyl-containing polysiloxanes (FPSs) was performed by the liquid-state ¹H, ¹³C, and ²⁹Si nuclear magnetic resonance (NMR) spectroscopy, gel permeation chromatography (GPC), and cyclic voltammetry. FPSs with tunable Fc unit content ranging from 20 to 100 mol% were obtained by anionic ring-opening polymerization (AROP). The ²⁹Si NMR spectroscopy indicates the successful anionic homopolymerization of the mono- and tetraferrocenyl-substituted cyclotetrasiloxanes (Fc₄D₄ and Fc₁D₄) by appearance of new signals of Si atoms corresponding to a polymer backbone. An analysis of pentad assignments in ²⁹Si NMR determined the anionic copolymerization of Fc₄D₄ with D₄ by indicating signals of neighboring Si atoms from different types of polymer units (D^F and D), which differ from the signals of homopolymers. The Mayo-Lewis copolymerization constants of Fc₄D₄ and D₄ were determined by the Fineman–Ross method. The molecular masses and unimodal molecular weight distribution of FPSs were estimated by using GPC. FPSs possess redox-activity. Thus, the proposed comprehensive approach analyzes structural features of the functional silicones with enhanced redox properties, which can be applied in (opto)electronics, coatings, and biomedicine.

Covalent adaptable networks (CANs) have attracted significant attention due to their potential to form crosslinked, yet reprocessable networks. Their ability to rearrange upon exposure to specific stimuli, in combination with properties such as self-healing can advance the development of novel materials, including for additive manufacturing. Thorough understanding of structure-property relations and processing potential will aid future application-driven research in network design as well as material selection. Therefore, a multitude of CANs were synthesized herein, by crosslinking epoxide-based oligomers via the furan-maleimide Diels-Alder reaction, to evaluate small systematic variations of (co)monomer composition, crosslinker length/flexibility and crosslinking density as vectors of tuning the CANs' thermomechanical properties. Networks with glass transition temperatures (T_g) spanning from <−40 °C up to >20 °C and Young's Moduli spanning from 0.2 MPa to >500 MPa were readily attainable. Crosslinker length/flexibility had a profound impact on the tensile properties, while changes in backbone composition provided insight into the impact of secondary interactions versus rigid moieties on mechanical performance. Self-healing at ambient conditions was demonstrated for elastomeric networks, with healing efficiency being enhanced when using longer crosslinkers. Finally, a cell viability and metabolic activity assay provided a preliminary in vitro demonstration of the biocompatibility of these materials.

Glucose selective oxidizing enzyme of glucose oxidase (GOD) was immobilized on the carboxyl group (–COOH) functionalized porous polyimide (PI) film (PI-GOD film). The –COOH functionalized film was fabricated by the modified breath figure method (BF) by casting the PI solution under humid conditions containing KOH. The amine group of GOD was covalently bonded to the PI-COOH film under catalytic conditions for the PI-GOD film. The PI-GOD film induced the color change of the bromothymol blue (BTB) indicator solution from green to yellow by adding glucose due to the oxidation of glucose by GOD to gluconic acid acting as an acidic source. Amine-terminated pH-sensitive polymethacrylic acid polymer (PMAA) was additionally immobilized to the PI-GOD film for the PI-GOD-PMAA film. The morphology of the pore surface of the PI-GOD-PMAA film was changed by the addition of glucose due to the coil-to-globule transition of the pH-sensitive polymer by the production of gluconic acid as a result of the reaction between glucose and GOD. The insulin adsorbed on the film was released by adding glucose due to the morphology change of the pH-sensitive polymer. The detection sensitivity of glucose was increased by the pore-selectively immobilized GOD acting as a micro-reactor.

Particulate matter (PM) is an air pollutant that poses a significant threat to human health. Efficient air filters are crucial for reducing PM pollution. However, several existing filtration materials fail under vigorous motion, such as twisting or stretching by high-velocity airflows, owing to their poor mechanical properties. In this study, we designed and fabricated a highly stretchable and biodegradable PM filtration membrane using electrospun polyacrylonitrile (PAN)/polycaprolactone (PCL) blended nanofibers. Our study incorporated polymer blend theory, particularly Hansen's solubility theory, to determine an optimal composition that not only provides particle absorption properties (minimizing PAN content without compromising absorption performance), but also significantly improves stretchability and biodegradability (maximizing PCL content). The resulting PAN/PCL air filters exhibited 100-times-enhanced stretchability and high filtration efficiency for PM2.5 (99.95%) and PM10 (99.89%), with a simultaneous low-pressure drop (121 Pa, only <1% of atmospheric pressure) under a high gas flow velocity (5 L/min ≈ face velocity of 0.3 m/s). Moreover, the 50/50 wt% PAN/PCL air filter demonstrated biodegradability, showing weight loss of up to 40% after 72 h of enzymatic degradation. Our highly efficient and biodegradable air filter, fabricated using PAN/PCL-blended nanofibers, offers new perspectives for the design and preparation of high-performance filtration materials. Moreover, it has potential applications in air pollution control and environmental protection.

Laboratory on-chip (LOC) technology facilitates numerous developments across diverse disciplines, such as medicine, tissue engineering, materials science, biomedical engineering, and biotechnology. Moreover, the potential applications appear boundless when LOC is integrated with intelligent hydrogels. In the literature, however, there are few accounts of the vast array of developments and applications that this combination has spawned. These new systems, which integrate smart hydrogels and LOC and thus significantly advance cutting-edge technology, have been thoroughly examined in this review. The functions of smart hydrogels in LOC applications were described and subsequently the developed intelligent hydrogels were classified as multi-responsive, thermo-responsive, pH-responsive, and stimuli-responsive (light, magnetic, and electric). Following this, details regarding tunable properties for LOC functions were provided, followed by a discussion of the fabrication processes and integration of these intelligent hydrogels into LOC systems, including their benefits and drawbacks. Following that, current literature examples of LOC systems utilizing these intelligent hydrogels for biosensing, 3D culture, tissue engineering, controlled release, personalized medicine, drug delivery, analyte enrichment, and organ-on-a-chip applications were presented. Following the presentation of state-of-the-art information regarding smart hydrogel characterization techniques, present challenges and prospective prospects were discussed.