Compatibility In Polymer Matrix Research Articles

Highly Water‐Dispersible Spiropyran‐Octapeptide Supramolecules: Efficient, Multi‐processable, and Versatile Photoswitches for Time‐Dependent Dual‐Mode Encryption

AbstractWith exceptional photochromic and photoluminescent properties, spiropyrans have demonstrated significant potential for advanced information encryption and anti‐counterfeiting applications. However, its inherent water insolubility leads to incompatibility with aqueous polymers, and even more, its ease of leaching from the matrix hinders the formation of stable stimuli‐responsive platforms through direct blending with all polymers. Here, the fabrication of amphiphilic spiropyran‐octapeptide molecules is reported that can spontaneously self‐assemble into highly water‐dispersible supramolecular nanofibers in water. These assemblies exhibit universal polymer matrix compatibility while retaining the rapid photo‐responsiveness of spiropyrans. The formation of strong interactions between the supramolecular assembly and polymer chains ensures the long‐term stability of the resultant stimuli‐responsive materials in aqueous environments. These platforms fully preserve the base polymers’ processing properties, with silk fibroin as the matrix offering exceptional opportunities for constructing photo‐responsive platforms in various forms (e.g., films, gels, fibers, and coatings) with multiple functionalities using diverse solution processing techniques. Integrating distinct photochromic and photoluminescent responses within a single format without interference, combined with environmental stability and processing flexibility, enables the creation of dual‐mode, high‐security encryption devices for diverse application scenarios. The outlined strategy provides innovative concepts for developing high‐performance, versatile intelligent systems utilizing stimulus‐responsive molecules.

Ultrastable emissive perovskite nanocomposite via dual protection of polymer-grafted TS-1 zeolite for backlight display application

Instability of all-inorganic perovskite quantum dots (PQDs) driven by the inherent ionic nature poses a grand challenge towards their long-term stability in optoelectronic devices. Herein, we report the crafting of a highly stable dual-protected CsPbBr3 perovskite nanocomposite by capitalizing on the encapsulation of a hydrophobic Styrene-Divinylbenzene (St-Dvb) copolymer grafted hierarchical titanium silicalite-1 (TS-1) zeolite shell. Firstly, an optimal hot injection method was used to accommodate CsPbBr3 PQDs into hierarchical TS-1 zeolite. After the modification of terminated Si-OH groups on the surface of TS-1 by phenyltriethoxysilane (PTES), a subsequent polymerization of St and Dvb was implemented using azobisisobutyronitrile (AIBN) as initiator to result in the highly emissive CsPbBr3-TS@St-Dvb nanocomposite, exhibiting outstanding luminescent stability against heat, polar solvents, and UV light irradiation. The as-prepared CsPbBr3-TS@St-Dvb nanocomposite also showed strongly suppressed anion exchange and high compatibility in polymer matrix, enabling improved applicability for versatile lighting and optical display applications. Ultimately, a white light-emitting diode (WLED) composed of green-emitting CsPbBr3-TS@St-Dvb and red-emitting K2SiF6:Mn4+ phosphor onto a commercial blue InGaN LED chip with wide color gamut and excellent stability is demonstrated. This work highlights a judiciously-designed and hard-soft dual-protected strategy to produce ultrastable perovskite nanomaterials with high brightness and durability for backlight display application.

Chitosan films plasticized with choline-based deep eutectic solvents: UV shielding, antioxidant, and antibacterial properties

Deep eutectic solvents (DES) as plasticizers of chitosan film show great potential for food packaging. This paper introduced some novel antioxidant and antibacterial films based on chitosan and DES consisting of choline chloride (ChCl) and organic acids. The effects of the composition and contents of choline-based DES on structures, mechanical properties, thermal stability, contact angle, optical, antioxidant and antibacterial properties of chitosan films were studied. FTIR analysis showed that choline-based DES did exist in the chitosan film with good polymer matrix compatibility. Most of the films exhibited uniform, flat surfaces and cross sections. The Young's modulus of the films decreased inversely to the level of choline-based DES, and maximal mechanical characteristics were achieved for films plasticized with ChCl and acetylsalicylic acid. The addition of choline-based DES apparently reduced water contact angles, decreased the decomposition temperature and the thermal stability of chitosan films. In terms of antioxidant capacities and ultraviolet (UV) shielding, chitosan films plasticized with choline-based DES containing acetylsalicylic acid and vitamin C had strong UV shielding and antioxidant properties. Chitosan films plasticized with choline-based DES containing acetylsalicylic acid, malonic acid and lactic acid showed excellent antibacterial properties against Escherichia coli and Staphylococcus aureus . In conclusion, the chitosan film with the choline-based DES, especially for ChCl and acetylsalicylic acid showed a good application prospect in food active packaging. Chitosan films plasticized with choline-based deep eutectic solvents: UV shielding, antioxidant, and antibacterial properties. • Novel chitosan films plasticized with 6 kind of deep eutectic solvents (DES) and 2 different levels addition were studied. • Chitosan films plasticized with choline-based DES containing acetylsalicylic acid or vitamin C had strong ultraviolet shielding and antioxidant activities. • Chitosan films plasticized with choline-based DES containing acetylsalicylic acid, malonic acid or lactic acid showed excellent antibacterial properties.

Sustainable mixed matrix membranes containing porphyrin and polysulfone polymer for acid gas separations

The synergetic effect of nitrogen-rich and CO2-philic filler and polymer in mixed matrix-based membranes (MMMs) can separate CO2 competently. The introduction of well-defined nanostructured porous fillers of pores close to the kinetic diameter of the gas molecule and polymer matrix compatibility is a challenge in improving the gas transportation characteristics of MMMs. This study deals with the preparation of porphyrin filler and the polysulfone (PSf) polymer MMMs. The fillers demonstrated uniform distribution, uniformity, and successful bond formation. MMMs demonstrated high thermal stability with a glass transition temperature in the range of 480–610 °C. The porphyrin filler exhibited microporous nature with the presence of π-π bonds and Lewis’s basic functionalities between filler-polymer resulted in a highly CO2-philic structure. The pure and mixed gas permeabilities and selectivity were successfully improved and surpass the Robeson’s upper bound curve's tradeoff. Additionally, the temperature influence on CO2 permeability revealed lower activation energies at higher temperatures leading to the gas transport facilitation. This can be granted consistency and long-term durability in polymer chains. These results highlight the unique properties of porphyrin fillers in CO2 separation mixed matrix membranes and offer new knowledge to increase comprehension of PSf performance under various contents or environments.

Drug-loading capacity of polylactide-based micro- and nanoparticles - Experimental and molecular modeling study.

Micro- and nanostructures prepared from biodegradable homopolymers and amphiphilic block copolymers (AmBCs) have found application as drug-delivery systems (DDSs). The ability to accumulate a drug is a very important parameter characterizing a given DDS. This work focuses on the impact of DDS size, the packing of polymer chains in the DDS, and drug - polymer matrix compatibility on the hydrophobic drug - loading capacity (DLC) of nano/microcarriers prepared from a biodegradable polymer or its copolymer. Using experimental measurements in combination with atomistic molecular dynamics simulations, an analysis of curcumin encapsulation in microspheres (MSs) from polylactide (PLA) homopolymer and nanoparticles (NPs) from PLA-block-poly(2-methacryloyloxyethylphosphorylcholine) AmBC was performed. The results show that curcumin has good affinity for the PLA matrix due to its hydrophobic nature. However, the DLC value is limited by the fact that curcumin only accumulates in the peripheral part of these structures. Such uneven drug distribution in the PLA matrix results from the non-homogeneous density of MSs (non-uniform packing of the polymer chains in the coil). The results also indicate that the MSs can retain a greater amount of hydrophobic drug compared to the NPs, which is associated with the formation of drug aggregates inside the PLA microparticles.

Amino-silane surface modification of urea-formaldehyde microcapsules containing linseed oil for improved epoxy matrix compatibility. Part I: Optimizing silane treatment conditions

In microcapsule-filled self-healing coatings, a good microcapsule/matrix interface improves repairing performance by directing the crack through the microcapsule and releasing the core material. In this study, the surface of the synthesized linseed oil filled polyurea-formaldehyde (PUF) based microcapsules was treated with 3-aminopropyltrimethoxy silane (APS, via a two-step sol-gel route), in order to improve its interface with an epoxy coating. The treated microcapsules were then characterized using various characterization techniques. The effect of silane treatment on the microcapsule/matrix interface and tensile properties of the coating was evaluated.FTIR spectroscopy showed both physical and chemical interactions between APS and PUF microcapsules. SEM micrographs revealed an almost spherical morphology for both treated and un-treated microcapsules. TGA results showed that the maximum silane grafting occurs at pH 7.5. It was found that the addition of APS-treated microcapsules had a positive effect on the tensile properties of the coating due to improving microcapsule’s shell and polymer matrix compatibility. This was related to the reaction of hydroxyl groups on PUF microcapsules and silanol groups of the silane and the subsequent reaction of amine group of the silane with the epoxy group of the coating.

Interlaminar Shear and Tensile Strengths of the Polymer Composites Based on CNT Films

Carbon nanotubes demonstrate excellent electrical, mechanical and thermal properties due to their unique structure. To bring this astonish properties into macroscale, CNTs were assembled into large scale film via FCCVD method. However, the obtained CNT film mechanical properties remained unsatisfactory and leaves room for further improvement. Herein, different mixtures of Epoxy and PVA polymer matrix were incorporated via vacuum assisted resin transfer molding (VARTM) technique into CNT film and successfully enhanced its mechanical properties. The obtained CNT film/Epoxy and CNT film/PVA tensile strength increased by 3.5 and 4.7 times compared to pristine CNT film tensile strength. In addition, polymer matrix compatibility with CNT film was investigated by interlaminar strength method. CNT films/epoxy composite exhibited significantly higher peeling strength (633.7 N/m) compared to those with PVA (70.8 N/m) demonstrating the good affinity of epoxy with CNT film.

Enhancement of compatibility based on vapor-phase-assisted surface polymerization (VASP) method for polymer composites with agricultural wastes

Cellulosic substances in polymer matrices are immiscible and non-dispersive because of mismatch between their surface properties. In order to fabricate a natural fiber-reinforced plastic, hydrophilic cellulosic substances should be modified to hydrophobicity to make it miscible and dispersible to polymer matrices. Herein, this work shows potential application of vapor-phase-assisted surface treatment as a new modification approach for cellulosic substances. Cellulosic substances were modified to improve the compatibility in the polymer matrix. The modified cellulose substrates were characterized by Fourier transform infrared spectrometer spectroscopy, thermogravimetric analysis, and scanning electron microscope, and the resulting shows the grafting polymer on cellulosic substances indeed. To more enhance compatibility in polymer matrix, grafting of the methacryloyl groups on cellulose substance was prepared through gaseous methacrylic anhydride on cellulose surface, and then higher modified cellulose substance was carried out with vapor-phase graft polymerization of methyl methacrylate finally. The vapor-phase-assisted surface treatments could highly modify the cellulose surface compared to conventional method in liquid process.

Thermal, mechanical, and morphological investigation of injection molded poly(trimethylene terephthalate)/carbon fiber composites

AbstractInjection molded poly(trimethylene terephthalate) (PTT)/carbon fiber (CF) composites have been fabricated using a twin screw micro compounder. The effect of CF reinforcement on the thermal, mechanical, dynamic mechanical, and microscopic properties of the composite was investigated. Addition of 30 wt% of CF into PTT resulted in the significant enhancement of tensile (120%) and flexural (30%) strength compared to neat PTT. The rule of mixture was successfully employed for theoretical calculations of tensile modulus and the calculated values were compared with the experimental results. Similarly, CF reinforced (30 wt%) PTT composites exhibited an increase of more than a 150°C in the heat deflection temperature. Scanning electron microscopy analysis of the tensile fracture specimens revealed uniform distribution of the CFs with good polymer matrix and fiber adhesion. Overall, the results obtained indicate the enhancement of properties with increasing fiber content, confirming better fiber and polymer matrix compatibility. POLYM. COMPOS., 33:1933–1940, 2012. © 2012 Society of Plastics Engineers

Study on Properties of Epoxy Resins Modified by Nano-Silica

Organic precursor of EP/PU was prepared by epoxy resin which was polyurethane toughened, and then modified epoxy resin adhesive was synthesized using nano-silica as modifier. Microstructure of composite materials was observed by scanning electron microscopy (SEM), the results showed that the inorganic phase had good compatibility in polymer matrix, and polyurethane in epoxy resin have formed the "island structure". The mechanical properties, thermal stability and dielectric loss, dielectric constant of composites were investigated. The results indicated that doping of appropriate amount of nano-silica could improve mechanical property, shear strength and impact strength of 2wt% SiO2/EP-PU were increased 173% and 106.67%, than that of pre-doping of composite, respectively. Thermal decomposition temperature (Td) was increased, Tdof 2wt%SiO2/EP-PU was increased 8.1°C than that of pre-doped of material. Dielectric constant (ε) was as follows: was decreased with the increase of frequency, but increased with the increase of inorganic component, dielectric loss (tanδ) was increased with the increase of frequency and inorganic doping.

Enhanced electrical conductivity of nylon 6 composite using polyaniline-coated multi-walled carbon nanotubes as additives

Aggregation in polymer composites is one of the major obstacles in the carbon nanotubes (CNTs) applications. Authentic CNTs are known to have very good electrical conductivity and mechanical strengths. Surface functionalization can avoid aggregation and help dispersion of CNTs, but reduces CNT’s electrical conductivities and mechanical strengths dramatically. It needs a good way to resolve the above dilemma situation; i.e., poor dispersion–good conductivity vs. good dispersion–poor conductivity. Herein, we demonstrate that in-situ polymerized polyaniline (PANI)-coated CNTs have good polymer matrix compatibility, and are superior electrically conductive fillers to nylon 6 composites. In this report, multi-walled CNTs (MWCNTs) were surface-modified with poly(acrylic acids) (PAA), followed by further coating with PANI. The electrical conductivity of (PANI-MWCNTs)-nylon 6 composite thin film was increased from 10 −12 to 7.3 × 10 −5 S/cm in the presence of 1 wt% PANI-coated MWCNTs prepared by physical mixing of PANI and PAA-grafted MWCNTs. When in-situ polymerized PANI-coated MWCNTs were added, the electrical conductivity of MWCNTs-nylon 6 composite was further enhanced by 3 orders to be 3.4 × 10 −2 S/cm at the same 1 wt% loading of MWCNTs. Both Fourier-transformed infrared and uv–visible absorption spectra indicate that there exist very strong site-specific charge transfer interactions between the quinoid rings of PANI and MWCNTs, which results in the superior electrical conductivity of MWCNT-nylon 6 composite.

The effect of receptor–polymer matrix compatibility on electrochemical properties of PEO-based polymer electrolytes containing supramolecular additives: Part 2. Ionic transport study

Poly(ethylene oxide)–lithium salt composite electrolytes containing two different derivatives of calix[4]arene were tested as anion complexing agents for I − and CF 3SO 3 −. Both calix[4]arene derivatives studied have identical anion coordination groups but they have different compatibility with the polymer matrix obtained by chemical linking of the oligo(ethylene oxide) chains to one of the studied calixarenes. The impedance spectroscopy studies showed that the addition of the anion receptor significantly changes the conductivity. The character of this changes strongly depends on the receptor used while the electrochemical stability of these two calixarene receptors measured by cyclic voltammetry is similar. It was also proved that addition of the anion receptor strongly changes the polymer matrix morphology and thermal behavior. By the comparison with the liquid systems which electrical properties were similar to the polymer matrix, we can assume that these changes are a result of anion–receptor interactions.

Design and Synthesis of Highly Efficient Nonlinear Optical Chromophores

ABSTRACTTwo series of highly hyperpolarizable nonlinear optical (NLO) chromophores, containing perfluoroaryl dicyanovinyl and phenyl tetracyanobutadienyl acceptors, have been designed and synthesized. These chromophores show good thermal and chemical stability. The 3D conformational structures, confirmed by computational modeling, enhance polymer matrix compatibility and decrease optical loss of the polymer films. The guest-host polymers of the chromophores show large electro-optical activities.