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Abstract Hydrophobicity enhancement of metal-free leather, which is crucial for improving its comprehensive performance, can be achieved by using amphiphilic copolymer retanning agents. However, the relationship between the sequential structure and the hydrophobic modification effect of amphiphilic copolymers remains unclear. Herein, an amphiphilic block copolymer was synthesized using stearyl methacrylate and 2-(dimethylamino)ethyl methacrylate via atom transfer radical polymerization, and the corresponding random copolymer with similar monomer compositions and molecular weights was prepared for comparison. The aggregation behavior of block and random copolymers was investigated. DLS and TEM results indicate that the block copolymer exhibits a larger aggregate size than the corresponding random copolymer. Molecular dynamics simulations suggest that the block copolymer aggregate exhibit a thicker hydrophilic shell and more concentrated distribution of cationic DMA block than the random copolymer aggregate. Subsequently, the block and random copolymers were used for the hydrophobic modification of metal-free tanned collagen fibers (CFs). The block copolymer shows superior binding capacity to CFs than the random one because of its larger size and more concentrated charge distribution. Hence, the block copolymer can form a dense and uniform hydrophobic film on the surface of collagen fibrils and endow CFs with higher hydrophobicity than the random one. This work provides theoretical guidance for modulating the hydrophobicity of CFs by tailoring the sequential structure of amphiphilic copolymers, which is expected to inspire the manufacturing of high-performance metal-free leather. Graphical Abstract

Despite the appealing properties of random copolymers, the use of these biomaterials in association with phospholipids is still limited, as several aspects of their performance have not been investigated. The aim of this work is the formulation of lipid/random copolymer platforms and the comprehensive study of their features by multiple advanced characterization techniques. Both biomaterials are amphiphilic, including two phospholipids (1,2-dioctadecanoyl-sn-glycero-3-phosphocholine (DSPC), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)) and a statistical copolymer of oligo (ethylene glycol) methyl ether methacrylate (OEGMA) and 2-(diisopropylamino) ethyl methacrylate (DIPAEMA). We examined the design parameters, including the lipid composition, the % comonomer ratio, and the lipid-to-polymer ratio that could be critical for their behavior. The structures were also probed in different conditions. To the best of the authors' knowledge, this is the first time that P(OEGMA-co-DIPAEMA)/lipid hybrid colloidal dispersions have been investigated from a membrane mechanics, biophysical, and morphological perspective. Among other parameters, the copolymer architecture and the hydrophilic to hydrophobic balance are deemed fundamental parameters for the biomaterial co-assembly, having an impact on the membrane's fluidity, morphology, and thermodynamics. Exploiting their unique characteristics, the most promising candidates were utilized for methotrexate (MTX) loading to explore their encapsulation capability and potential antitumor efficacy in vitro in various cell lines. [ABSTRACT FROM AUTHOR]

Ultrasmall silica colloid particles (SCPs) show broad applications in various fields, including cosmetics, paint, medicine, and electronics. However, the precise and scalable synthesis of ultrasmall SCPs remains challenging. This study introduces a facile polymer-based strategy for the synthesis of ultrasmall SCPs through the synergistic utilization of solvophobic interactions and electrostatic repulsion. The size of SCPs can be efficiently modulated by the ratio between solvophilic and solvophobic segments within random copolymers. This approach allows for producing SCPs with a diameter of down to 9.6 ± 1.7 nm and a solid content of up to 9.8%. Furthermore, amphiphilic SCPs were obtained by introducing PEO blocks into copolymer templates and modifying with long carbon chain silane coupling agent. [ABSTRACT FROM AUTHOR]

Hydrophobicity enhancement of metal-free leather, which is crucial for improving its comprehensive performance, can be achieved by using amphiphilic copolymer retanning agents. However, the relationship between the sequential structure and the hydrophobic modification effect of amphiphilic copolymers remains unclear. Herein, an amphiphilic block copolymer was synthesized using stearyl methacrylate and 2-(dimethylamino)ethyl methacrylate via atom transfer radical polymerization, and the corresponding random copolymer with similar monomer compositions and molecular weights was prepared for comparison. The aggregation behavior of block and random copolymers was investigated. DLS and TEM results indicate that the block copolymer exhibits a larger aggregate size than the corresponding random copolymer. Molecular dynamics simulations suggest that the block copolymer aggregate exhibit a thicker hydrophilic shell and more concentrated distribution of cationic DMA block than the random copolymer aggregate. Subsequently, the block and random copolymers were used for the hydrophobic modification of metal-free tanned collagen fibers (CFs). The block copolymer shows superior binding capacity to CFs than the random one because of its larger size and more concentrated charge distribution. Hence, the block copolymer can form a dense and uniform hydrophobic film on the surface of collagen fibrils and endow CFs with higher hydrophobicity than the random one. This work provides theoretical guidance for modulating the hydrophobicity of CFs by tailoring the sequential structure of amphiphilic copolymers, which is expected to inspire the manufacturing of high-performance metal-free leather. [ABSTRACT FROM AUTHOR]

Photochromic azobenzenes undergo light-mediated trans-cis isomerization. The cis isomer reverts to the trans isomer thermally. To investigate the effect of different monomer sequences on the thermal stability of cis-azobenzene, a series of copolymers, namely, block, and random structures containing stearic acid and azobenzene moieties as their side chains have been synthesized through reversible addition-fragmentation chain transfer (RAFT) polymerization. In this study, we investigate the photoisomerization of the trans and cis forms of the polymers and also the thermal reversal of the cis-azobenzene photochromic systems. The isomerization data revealed significant differences in the isomerization timescales between the polymers and the corresponding monomer. It was observed that the local polarity around the azobenzene units within a polymer was significantly influenced by the chain segment depending on whether it was in the vicinity of the hydrophobic alkyl chains or other azobenzene units. This local environment of the azobenzene units regulates the stabilization of the transition states during the cis-trans thermal isomerization, consequently affecting the half-life of the cis isomer. [ABSTRACT FROM AUTHOR]

Despite the appealing properties of random copolymers, the use of these biomaterials in association with phospholipids is still limited, as several aspects of their performance have not been investigated. The aim of this work is the formulation of lipid/random copolymer platforms and the comprehensive study of their features by multiple advanced characterization techniques. Both biomaterials are amphiphilic, including two phospholipids (1,2-dioctadecanoyl-sn-glycero-3-phosphocholine (DSPC), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)) and a statistical copolymer of oligo (ethylene glycol) methyl ether methacrylate (OEGMA) and 2-(diisopropylamino) ethyl methacrylate (DIPAEMA). We examined the design parameters, including the lipid composition, the % comonomer ratio, and the lipid-to-polymer ratio that could be critical for their behavior. The structures were also probed in different conditions. To the best of the authors’ knowledge, this is the first time that P(OEGMA-co-DIPAEMA)/lipid hybrid colloidal dispersions have been investigated from a membrane mechanics, biophysical, and morphological perspective. Among other parameters, the copolymer architecture and the hydrophilic to hydrophobic balance are deemed fundamental parameters for the biomaterial co-assembly, having an impact on the membrane’s fluidity, morphology, and thermodynamics. Exploiting their unique characteristics, the most promising candidates were utilized for methotrexate (MTX) loading to explore their encapsulation capability and potential antitumor efficacy in vitro in various cell lines.

Polymer based phase change materials (PCM) for thermal energy storage (TES) applications have gained some attention recently due to their high stability and potential solid to solid phase transition. Here, we are the first to utilize a simple copolymerization strategy for static tunability transition temperature (Tt) of polymeric PCM. The copolymerization between short and long side chain polyethylene glycol based methacrylate polymers was designed to tune Tt with minimum impact on their energy density. Polarized optical microscope and x-ray techniques were also used to understand the relationship between crystal structure and Tt of different copolymer composition which was discussed in the context. The solid to solid transition polymeric PCM were successfully developed with tunable Tt ranged from 18 °C to 35 °C which is suitable toward building envelop applications.

Polymer based phase change materials (PCM) for thermal energy storage (TES) applications have gained some attention recently due to their high stability and potential solid to solid phase transition. Here, we are the first to utilize a simple copolymerization strategy for static tunability transition temperature (Tt) of polymeric PCM. The copolymerization between short and long side chain polyethylene glycol based methacrylate polymers was designed to tune Tt with minimum impact on their energy density. Polarized optical microscope and x-ray techniques were also used to understand the relationship between crystal structure and Tt of different copolymer composition which was discussed in the context. The solid to solid transition polymeric PCM were successfully developed with tunable Tt ranged from 18 °C to 35 °C which is suitable toward building envelop applications.

Adsorption of a single AB random copolymer (RC) chain onto homogeneous and inhomogeneous ab surfaces with a regular periodic pattern is studied theoretically. For the averaging over disorder in the RC sequence, the constrained annealed approximation, known as the Morita approximation is employed. A general scheme for constructing the Morita approximation of an arbitrary order m is proposed; it is based on representation of the RC monomer sequence as a Markov chain of overlapping (m –1)-ads. The problem is solved within the framework of the generating functions approach for the two-dimensional partially directed walk model of the polymer on a square lattice. Temperature dependences of various adsorption characteristics are obtained. The accuracy of the Morita approximation is assessed by comparison with the numerical results for RC with quenched sequences obtained by the transfer matrix approach. It is shown that for RC adsorption on a homogeneous surface for AB -copolymers with adsorbing A and neutral B blocks, it is sufficient to use the Morita approximation of second or third order. If the non-adsorbing B block is repelled from the surface, then a higher order of the approximation (5th–6th) is required. An important indicator of validity of the Morita approximation is the entropy: if the order of the approximation is not high enough, the entropy becomes negative in the low-temperature regime which means that the Morita approximation is wrong in this order. In the case when the surface is periodically inhomogeneous, the Morita approximation works worse and very high orders are required, which can be beyond the computational capabilities. Moreover, the Morita approximations become degenerate: approximations of two or more consecutive orders give the same result. [ABSTRACT FROM AUTHOR]

Amphiphilic copolymer self-assembly is a straightforward approach to obtain responsive micelles, nanoparticles, and vesicles that are particularly attractive for biomedicine, i.e., for the delivery of functional molecules. Here, amphiphilic copolymers of hydrophobic polysiloxane methacrylate and hydrophilic oligo (ethylene glycol) methyl ether methacrylate with different lengths of oxyethylenic side chains were synthesized via controlled RAFT radical polymerization and characterized both thermally and in solution. In particular, the thermoresponsive and self-assembling behavior of the water-soluble copolymers in water was investigated via complementary techniques such as light transmittance, dynamic light scattering (DLS), and small-angle X-ray scattering (SAXS) measurements. All the copolymers synthesized were thermoresponsive, displaying a cloud point temperature (Tcp) strongly dependent on macromolecular parameters such as the length of the oligo(ethylene glycol) side chains and the content of the SiMA counits, as well as the concentration of the copolymer in water, which is consistent with a lower critical solution temperature (LCST)-type behavior. SAXS analysis revealed that the copolymers formed nanostructures in water below Tcp, whose dimension and shape depended on the content of the hydrophobic components in the copolymer. The hydrodynamic diameter (Dh) determined by DLS increased with the amount of SiMA and the associated morphology at higher SiMA contents was found to be pearl-necklace-micelle-like, composed of connected hydrophobic cores. These novel amphiphilic copolymers were able to modulate thermoresponsiveness in water in a wide range of temperatures, including the physiological temperature, as well as the dimension and shape of their nanostructured assemblies, simply by varying their chemical composition and the length of the hydrophilic side chains. [ABSTRACT FROM AUTHOR]

The presence of impurities such as H2S, thiols, ketones, and permanent gases in propylene of fossil origin and their use in the polypropylene production process affect the efficiency of the synthesis and the mechanical properties of the polymer and generate millions of losses worldwide. This creates an urgent need to know the families of inhibitors and their concentration levels. This article uses ethylene green to synthesize an ethylene–propylene copolymer. It describes the impact of trace impurities of furan in ethylene green and how this furan influences the loss of properties such as thermal and mechanical properties of the random copolymer. For the development of the investigation, 12 runs were carried out, each in triplicate. The results show an evident influence of furan on the productivity of the Ziegler–Natta catalyst (ZN); productivity losses of 10, 20, and 41% were obtained for the copolymers synthesized with ethylene rich in 6, 12, and 25 ppm of furan, respectively. PP0 (without furan) did not present losses. Likewise, as the concentration of furan increased, it was observed that the melt flow index (MFI), thermal (TGA), and mechanical properties (tensile, bending, and impact) decreased significantly. Therefore, it can be affirmed that furan should be a substance to be controlled in the purification processes of green ethylene. [ABSTRACT FROM AUTHOR]

Random copolymer nanoparticles are studied by Monte Carlo simulation of coarse‐grained models on the second nearest neighbor diamond (2nnd) lattice. Molecular and surface properties of free‐standing nanoparticle are characterized as a function of co‐monomer fraction. "Polyethylene‐like copolymer" chains are treated by the Rotational Isomeric State (RIS) model of polyethylene (PE). To mimic the characteristics of copolymer chain, non‐bonded interactions with stronger attraction of comonomer units are described by different Lennard‐Jones (LJ) potential parameters. For higher co‐monomer fraction, the bulk densities of nanoparticles are increased and the interfacial profile is sharper. Molecular dimension and shape are changed as a function of co‐monomer composition and mostly in the region close to the surface. [ABSTRACT FROM AUTHOR]

The copolymer synthesis process can be affected by failures in the production process or by contaminating compounds such as ketones, thiols, and gases, among others. These impurities act as an inhibiting agent of the Ziegler–Natta (ZN) catalyst affecting its productivity and disturbing the polymerization reaction. In this work, the effect of formaldehyde, propionaldehyde, and butyraldehyde on the ZN catalyst and the way in which it affects the final properties of the ethylene-propylene copolymer is presented by analyzing 30 samples with different concentrations of the mentioned aldehydes along with three control samples. It was determined that the presence of formaldehyde 26 ppm, propionaldehyde 65.2 ppm, and butyraldehyde 181.2 ppm considerably affect the productivity levels of the ZN catalyst; this effect increases as the concentration of aldehydes is higher in the process; likewise, these impurities affect the properties of the final product, such as the fluidity index (MFI), thermogravimetric analysis (TGA), bending, tension, and impact, which leads to a polymer with low-quality standards and less resistance to breakage. The computational analysis showed that the complexes formed by formaldehyde, propionaldehyde, and butyraldehyde with the active center of the catalyst are more stable than those obtained by the ethylene-Ti and propylene-Ti complexes, presenting values of −40.5, −47.22, −47.5, −5.2 and −1.3 kcal mol−1 respectively. [ABSTRACT FROM AUTHOR]

Random copolymerization is a promising strategy for finely modulating crystal, morphological, and electrical properties of semiconducting conjugated polymers for electronic device applications. Herein, a new series of regio-random thiophene polymers were synthesized by partially substituting non-alkylated furan units into the conjugated backbone to enhance the inter- and intramolecular interactions. The systematic tuning of the monomer ratio revealed the dramatic effects of furan substitution on the charge transport ability of the polymers. The optimized-polymer field-effect transistors showed enhanced mobility of over 4 cm2V−1s−1 compared to the control polymer with no furan substitution (≈2 cm2V−1s−1), using electrolyte gating, which substantially exceeds devices with conventional polymer dielectric (10−2 cm2V−1s−1), attributing to improved charge carrier density in the semiconducting channel and film crystallinity. Also, using the synthesized polymers as hole transport materials for silver bismuth sulfide (AgBiS 2) nanocrystal solar cells showed high power conversion efficiencies of 5.75 % and 4.09 % for the optimized and control polymers, respectively. This study will provide new insight into improving the crystallinity of random polymers for high-performance solution-processable electronic devices. [Display omitted] • Polythiophenes were synthesized by partially substituting with furan unit. • Furan substitution enhanced the molecular ordering of polymers. • An enhanced mobility of 4.1 cm2 V−1 s−1 in OFETs was achieved. • An improved efficiency of 5.7 % in AgBiS 2 solar cells was achieved. [ABSTRACT FROM AUTHOR]

Polymeric material draws a great attraction in the development of insulation for High Votage Direct Current (HVDC) applications. Insulation material is the deciding key factor to increase the operating voltage and to transmit the bulk power with minimized power loss. Premature breakdown, high withstanding temperature, and impacts of space charge accumulation are all issues faced by the insulation material. Material qualities such as dielectric, electrical, structural, and mechanical properties are directly affected by the issues. Therefore, this paper provides an overview of the dielectric properties of polymeric materials and their composites under various stress conditions. The stress includes AC, DC, superimpose and combined (AC and DC) stress under which the dielectric constant, dielectric losses, electrical strength, and space charge distribution of polymeric insulating materials such as low‐density polyethylene, high‐density polyethylene, cross‐linked polyethylene, polypropylene, and random copolymer (RCP), as well as their composites, are explored. Polypropylene and RCP outperform all other polymers in terms of breakdown strength and space charge suppression under various stress conditions. RCP is a developing material that also has the potential to be an effective thermoplastic insulation material in the future. [ABSTRACT FROM AUTHOR]

In this contribution, we reported the investigation of styrene–butadiene rubber (SBR) reinforced by kaolin-graft-polyisoprene (Mkaol). First, poly(isoprene-maleic anhydride) random copolymers (PIPMA) which was used as macromolecular surface modifiers were synthesized via reversible addition-fragmentation chain transfer polymerization (RAFT). Second, the PIPMA was sprayed onto the surface of kaolin to obtain MKaol. FTIR spectroscopy indicated that the surface of MKaol was covered with a layer of PIPMA. MKaol and kaolin were simultaneously incorporated into SBR. The storage modulus (G′) of SBR/kaolin compounds at low strains was much lower than the G′ of SBR/MKaol. The curing properties showed that the vulcanization rate of the SBR/MKaol compounds was much lower than that of the SBR/kaolin. The cross-link density of SBR/kaolin was slightly higher than those of SBR/MKaol. The SEM images revealed that kaolin microdomains in the SBR/MKaol vulcanizates were much better distributed and dispersed than in the SBR/kaolin composites. Compared to filler dispersion and filler–rubber interaction of the SBR/kaolin composites, the mechanical properties (tensile strength, elongation at break, and tear strength) of the SBR/MKaol composites were significantly improved. Poly(isoprene-maleic anhydride) random copolymers (PIPMA) which was used as macromolecular surface modifiers were synthesized via reversible addition-fragmentation chain transfer polymerization (RAFT). PIPMA was sprayed onto the surface of kaolin to obtain MKaol. The storage modulus (G′) of SBR/kaolin compounds at low strains was much lower than the G′ of SBR/MKaol compounds. The curing properties showed that the vulcanization rate of the SBR/MKaol compounds was much lower than that of the SBR/kaolin compounds. Kaolin microdomains in the SBR/MKaol vulcanizates were much better to disperse and distribute than in the SBR/kaolin composites. Compared to the SBR/kaolin composites, the mechanical properties of SBR/MKaol composites were greatly improved. [ABSTRACT FROM AUTHOR]

The design of donor-acceptor (D-A)-based random copolymers-type hole transporting materials (HTMs) are important for achieving superior performance of perovskite solar cells (PSCs) with high durability. In this work, a 2-alkylthienyl-substituted benzodithiophene (BDTT)-based random copolymer (denoted as RCP-BDTTPD), containing 2-ethylhexylthiophene-substituted benzo[1,2-b:4,5-b′]dithiophene (BDTT as an electron-donor; M1) and two different side-chain functionalized thieno[3,4-c]-pyrrole-4,6‑dione as the electron-acceptors (M2 and M3), is prepared and applied as an efficient interfacial HTM for PSCs. The optical, electrochemical, and electronic properties of RCP-BDTTPD are shown to be structurally and energetically viable to serve as HTM for PSCs. The RCP-BDTTPD has deeper highest occupied molecular orbitals (HOMO; −5.53 eV) and lowest unoccupied molecular orbitals (LUMO; −3.57 eV) energy levels. This is shown to be energetically suitable for realizing better compatibility with Cs-containing formamidinium/methylammonium (FAMA) mixed-cation perovskite as light absorber having HOMO energy level (−5.85 eV). The RCP-BDTTPD possessing gradient band alignment with perovskite, which is shown to be highly significant for the extraction of charge carriers, resulting in higher hole mobility of PSCs. RCP-BDTTPD delivered a reasonably good V oc of 1.10 V and higher J sc of 19.01 mAcm−2 and, champion power conversion efficiency (PCE) up to 15.30 % with hole mobility (1.34×10−3 cm2V−1s−1) and high durability (Encapsulated cell retention of its PCE about 98 % over 16 h under harsh environment: Temp. ∼85 °C, RH∼85 %). This work demonstrating a potential application of RCP-BDTTPD based HTMs for the fabrication of high-performance PSCs with high durability as well as low cost. [Display omitted] [ABSTRACT FROM AUTHOR]

Amphiphilic copolymer self-assembly is a straightforward approach to obtain responsive micelles, nanoparticles, and vesicles that are particularly attractive for biomedicine, i.e., for the delivery of functional molecules. Here, amphiphilic copolymers of hydrophobic polysiloxane methacrylate and hydrophilic oligo (ethylene glycol) methyl ether methacrylate with different lengths of oxyethylenic side chains were synthesized via controlled RAFT radical polymerization and characterized both thermally and in solution. In particular, the thermoresponsive and self-assembling behavior of the water-soluble copolymers in water was investigated via complementary techniques such as light transmittance, dynamic light scattering (DLS), and small-angle X-ray scattering (SAXS) measurements. All the copolymers synthesized were thermoresponsive, displaying a cloud point temperature (Tcp) strongly dependent on macromolecular parameters such as the length of the oligo(ethylene glycol) side chains and the content of the SiMA counits, as well as the concentration of the copolymer in water, which is consistent with a lower critical solution temperature (LCST)-type behavior. SAXS analysis revealed that the copolymers formed nanostructures in water below Tcp, whose dimension and shape depended on the content of the hydrophobic components in the copolymer. The hydrodynamic diameter (Dh) determined by DLS increased with the amount of SiMA and the associated morphology at higher SiMA contents was found to be pearl-necklace-micelle-like, composed of connected hydrophobic cores. These novel amphiphilic copolymers were able to modulate thermoresponsiveness in water in a wide range of temperatures, including the physiological temperature, as well as the dimension and shape of their nanostructured assemblies, simply by varying their chemical composition and the length of the hydrophilic side chains.

Co-crystallization of different monomeric units fundamentally contributes to the versatile and tunable performance of random copolymers. At present, the crystallization manners of random binary copolymers have been divided into three categories: isomorphism, isodimorphism and comonomer exclusion. Each category, however, has its own advantages and disadvantages. Therefore, it is challenging to design and prepare random copolymer sharing the advantages of isomorphism and isodimorphism through a new co-crystallization manner beyond the ones already exist. On the basis of previous study on poly(alkylene succinate-ran-alkylene fumarate) whose co-crystallization can be extensively and finely regulated by simply varying the chemical structure of alkylene, random copolymers of poly(propylene succinate-ran-propylene fumarate) (PPSF) are synthesized using 1,3-propanediol as the diol source. The thermal properties and crystal structure of PPSF are investigated, and, intriguingly, it is proved that PPSF is an isodimorphism system while displays similar composition-dependent thermal properties and crystallinity as isomorphism. That is, PPSF exhibits a novel co-crystallization behavior that has rarely been discovered, which would combine the advantages of both isomorphism and isodimorphism. Consequently, PPSF could be termed as a new-type, special composition-dependent polymorphism. Besides, the altering of PPS-like to PPF-like crystal structure of PPSF when changing chain composition has been proved to originate from the shift of dominant inter-segment interaction from van der Waals forces to strong hydrogen-bonding interaction. This work enriches the co-crystallization manner of random copolymers, leading to more diverse performance design of polymer materials. [ABSTRACT FROM AUTHOR]

Degradable vinyl polymers by radical ring‐opening polymerization are promising solutions to the challenges caused by non‐degradable vinyl plastics. However, achieving even distributions of labile functional groups in the backbone of degradable vinyl polymers remains challenging. Herein, we report a photocatalytic approach to degradable vinyl random copolymers via radical ring‐opening cascade copolymerization (rROCCP). The rROCCP of macrocyclic allylic sulfones and acrylates or acrylamides mediated by visible light at ambient temperature achieved near‐unity comonomer reactivity ratios over the entire range of the feed compositions. Experimental and computational evidence revealed an unusual reversible inhibition of chain propagation by in situ generated sulfur dioxide (SO2), which was successfully overcome by reducing the solubility of SO2. This study provides a powerful approach to degradable vinyl random copolymers with comparable material properties to non‐degradable vinyl polymers. [ABSTRACT FROM AUTHOR]

The aim of this work is to investigate the preparation, the optical properties, and the stability over time of a colloidal organic-inorganic hybrid perovskite (CH3NH3PbBr3)/random copolymer P(MMA-co-DMAEMA) system. Different ratios of perovskite to copolymer were used to study its effect on stability and properties. The optical properties were investigated by UV-Vis and fluorescence spectroscopy. Dynamic light scattering was used to determine the size, and the size polydispersity of the colloidal hybrid particles; while morphology was investigated by transmission electron microscopy. Photoluminescence decay studies revealed the interaction of the random copolymer with the perovskite. Finally, thin-films were prepared, to investigate the optical properties of the samples in the absence of the solvent. High temporal stability of the optical properties of thin hybrid films was observed under certain conditions. [ABSTRACT FROM AUTHOR]

Molecular and structural properties of random copolymer thin films were studied by Monte Carlo simulation of coarse-grained copolymer model on the high coordination lattice. Random copolymer thin films with 50% comonomer fraction with varied interaction strength between comonomer units were studied. Intramolecular interaction was represented by Flory's rotational isomeric state (RIS) model of polyethylene (PE). The non-bonded interactions were treated by Lennard–Jones potential with different parameter sets for comonomer units. When the interaction strength of comonomer is increased, the density of thin films is higher in the inner region and significantly dropped near the free surface along the normal direction of the film. Higher bulk densities and narrower interfacial thicknesses are observed for random copolymer with stronger bead interaction. End beads were segregated at the free surface region and tend to orient perpendicularly to the surface. Copolymer size and shape were significantly changed as a function of bead interaction. For orientation of the whole chain, the largest molecular axis tends to orient along the film surface, but changed toward random orientation for weaker bead interaction. The intra-chain energies were decreased at the surface region while the non-bonded energies were increased. The stronger the comonomer bead attraction, the more change in energetics across the thin film. [ABSTRACT FROM AUTHOR]

A series of amphiphilic block and random copolymers based on phenylboronic acid pinacol ester were synthesized via reversible addition–fragmentation chain transfer polymerization. The obtained copolymers can self-assemble in aqueous solution into stable block copolymer nanoparticles and random nanoparticles with sizes of 116.1–158.6 and 126.3–187.0 nm, respectively. All nanoparticles showed hydrogen peroxide (H2O2) sensitivity, and the random copolymer nanoparticles presented faster responsiveness to H2O2 than did those derived from block copolymers. Berberine (BBR) can be effectively encapsulated into block and random copolymer nanoparticles with loading capacity of 7.6%–9.1% and 7.3%–8.9%, respectively. The BBR release can be controlled in an H2O2 medium. For the random copolymer nanoparticles, the release rate of BBR was faster and the cumulative release amounts in response to H2O2 were higher over 48 h. The BBR cumulative release amount in the H2O2 medium for the block and random copolymer nanoparticles was 62.2%–70.2% and 68.6%–80.4%, respectively. Moreover, good biocompatibility was observed for the BBR-loaded block and random copolymer nanoparticles. BBR and BBR-loaded nanoparticles can improve Glut4 translocation to the cell membrane and promote glucose transport into cells. BBR-loaded nanoparticles can decrease the blood glucose levels in diabetic rats over 15 days. These results imply that the different chain formulation of block and random copolymers affects the H2O2 responsiveness and that the two kinds of nanoparticles exhibit potential application as novel vehicles for BBR delivery to regulate blood glucose levels. [ABSTRACT FROM AUTHOR]

Octamethylcyclotetrasiloxane and 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane were ring opening polymerized to prepare vinyl terminated poly(dimethyl-co-methylvinyl)siloxane and the effect of the reaction conditions on the molecular weight, the reaction yield, the structure, and the composition of the copolymer was studied. When excess end capping agents are added and the reaction is carried out under a condition where its reaction is favorable, ring opening occurs rapidly and high reaction yield and low molecular weight products can be obtained. When the reaction temperature is set far from the activation temperature of the end capping agent, relatively high molecular weights can be obtained, however, the time required for ring opening increases and the reaction yield decreases significantly. At 120 °C where the ring opening occurs relatively stably, minimizing the amount of end capping agent increased the molecular weight and the reaction yield simultaneously. Due to the lower reactivity of octamethyl-cyclotetrasiloxane relative to 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, at lower copolymerization temperatures the content of dimethyl siloxane block in the copolymer is lower than the feed composition and the product is mainly random copolymers. [ABSTRACT FROM AUTHOR]

At selective liquid–liquid interface, amphiphilic homopolymers, having groups with different affinity for the liquids in each monomer unit, would demonstrate higher occupation of the interfacial layer than copolymers with various distributions of groups and be advantageous as interface stabilizers. By means of Langevin dynamics computer simulation, conformations of multiple chains of amphiphilic macromolecules adsorbed at the liquid–liquid interface were studied. Monomer units having different affinity for the liquids were distributed variously along the polymer chains. Homopolymers, amphiphilic at the level of an individual monomer unit, and copolymers with random, altermating and multiblock distribution of groups were considered. The surface coverage, structure of the layer, and spatial distribution of monomer units were investigated depending on the polymer concentration. Compared to copolymers with random, alternating and multiblock distributions of the groups, the interfacial layer concentration of amphiphilic homopolymer is about 1.5 times higher, the adsorbed layer is remarkably thinner, has membrane-like structure and is asymmetric with respect to interface boundary. Also, the adsorbed amphiphilic homopolymers form fewer loops and tails, most located on one side of the interface. This combination of properties is promising for practical application in modern self-assembling molecular devices. [ABSTRACT FROM AUTHOR]

This study developed a simple and efficient strategy to stabilize inorganic halide perovskite CsPbX3 at high relative humidity by embedding it into the matrix with elastic and self-healing features. The polymer matrix has a naturally hydrophobic characteristic of n-butyl acrylate segment (n-BA) and cross-linkable and healable moiety from N-(hydroxymethyl) acrylamide segment (NMA). It was chosen due to the provisions of both a surrounding protective layer for inorganic perovskite and elastic, as well as healing ability to the whole organic-inorganic composite. This fabricated CsPbBr3/PBA-co-PNMA composite was demonstrated to stably persist against the suffering from hydrolysis of perovskites when exposed to a high moisture environment. The PL intensity of the composite after crosslinking was found to be relatively stable after 30 days of exposure to air. Upon water immersion, the PL intensity of composite only showed a decrease of 32% after the first 6 h, then remained stable for 6 h afterward. Furthermore, this fabricated composite was not only flexible and relatively transparent but also exhibited excellent self-healing capability in ambient conditions (T = 25°C), in which the self-healing efficiency after 24 h was above 40%. The tensile strength and stretching ability of 5 wt% perovskite content in the random copolymer were observed to be 3.8 MPa and 553.5% respectively. Overall, flexible and self-healing properties combining with high luminescence characteristics are very promising materials for next-generation soft optical devices.

Donor–acceptor (D–A) random copolymers containing thienoisoindigo (TIG), diketopyrrolopyrrole (DPP), and benzothiadiazole (BT) acceptor units (Pa1-5 with TIG/DPP acceptor units, and Pb1-5 with TIG/BT acceptor units) have been developed. The typical Stille cross-coupling polymerization afforded D–A random copolymers with various acceptor compositions by adjusting monomer feed ratios. The obtained polymers exhibited the excellent light absorption by utilizing intramolecular charge transfer between donor and acceptor units. In particular, one of random copolymers with TIG/BT acceptor units (Pb2) accomplished the wide-range absorption in the range of 300–1400 nm in the thin film state. In the cyclic voltammetry analysis, the HOMO levels of polymers were successfully tunable in the wide range of − 4.86 to − 5.25 eV. The obtained results demonstrated that the D–A random copolymer could be a promising design for tailored and wide tuning of polymer properties, leading to the development of conjugated polymeric materials and their optoelectrical applications. [ABSTRACT FROM AUTHOR]

Synthesized a random copolymer here, namely P(zNDT-TPDBT), consisting of an electron-rich unit 'zig-zag' 4,9-bis-(2-ethylhexyloxy)naphtho[1,2-b:5,6-b']dithiophene (zNDT) and different ratio of two-electron acceptor units of thieno[3,4-c]pyrrole-4,6-dione (TPD) and benzodiathiazole (BT) via Stille coupling polymerization. The photophysical, electrochemical, and photovoltaic properties of P(zNDT-TPDBT) were investigated. The differences in the photophysical property of P(zNDT-TPDBT) indicate (i) red-shifted and broadening absorption spectrum located at 509 nm in thin-film as compared to solution (λmax = 492 nm) (ii) the fluorescence spectrum shows dual emission bands at 545 nm and 608 nm in the longer wavelength in solution, however, relatively complete quenching fluorescence property was observed in blended film with PC71BM. The copolymer exhibited an optical bandgap of 2.03 eV, with a highest occupied molecular orbital (HOMO) level of −5.87 eV. The optimized structure for the copolymer was also determined through DFT calculation. The bulk-heterojunction (BHJ) polymer solar cell (PSC) with a device structure of ITO/PEDOT:PSS/P(zNDT-TPDBT):PC71BM/Al exhibited a promising efficiency of 2.4% with the short circuit current density (Jsc) of 5.7 mA cm−2, open-circuit voltage (Voc) of 0.91 V, and fill factor (FF) of 47%, without processing addictive. The clear correlations between film morphology and device efficiency were observed through atomic force microscopy technique. [ABSTRACT FROM AUTHOR]

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In combination with methyllithium, a 2,6-bis(amino)phenol zinc complex 1 was used in the ring-opening polymerization of δ-valerolactone in the absence or presence of benzyl alcohol and showed high efficiency, mainly producing cyclic and linear polyvalerolactones, respectively. On the basis of homopolymerization, the ring-opening copolymerization of ε-caprolactone and δ-valerolactone was investigated. The P(CL-co-VL) random copolymers, PCL-b-PVL and PVL-b-PCL diblock copolymers, were prepared by varying the feeding strategy (premixing or sequential feeding). The copolymer composition was adjusted by varying the feeding ratio of two monomers. The structure and thermal properties of obtained polymers were characterized by GPC, 1H-NMR, 13C-NMR, MALDI-TOF mass spectroscopy, and DSC, respectively. [ABSTRACT FROM AUTHOR]

Fibrinogen adsorption behavior on the blood-compatible polymer, poly(2-methoxyethyl acrylate) (PMEA), non-blood-compatible polymer, poly(n-butyl acrylate) (PBA), and random copolymers of both were examined. Adsorption and denaturation of fibrinogen on the polymers increased as the ratio of PBA increased. The incremental change corresponded to the amount of intermediate water included in the hydrated polymers. The composition of PBA altered the features of the phase-separated structures observed on the polymer/phosphate-buffered saline interfaces. Microscopically, the denaturation of fibrinogen was observed as the formation of fibrous networks on the interfaces by atomic force microscopy. Fibrinogen adsorption and denaturation were enhanced on the water-rich domains in the phase-separated structures on the non-blood-compatible polymers. This suggested that the excellent blood compatibility of PMEA is caused by the constrained adsorption and denaturation of fibrinogen in water-rich domains, possibly due to the high content of intermediate water in this region. This work provides essential scientific foundations for the design and fabrication of highly functional biomaterials. [ABSTRACT FROM AUTHOR]

Lipid/polymer nanoparticles are among the most promising hybrid nanoplatforms for pharmaceutical applications, and their many advantages are well established. Despite the efforts, the design parameters that influence their performance have not been deciphered in total yet. In this study, thermodynamic evaluation of lipid and lipid/copolymer bilayers was conducted via differential scanning calorimetry (DSC). Based on their biophysical behavior and by modulating different design parameters for each system, selected lipid/copolymer nanostructures were prepared by the thin film hydration method. The biomaterials of choice were 1,2-dioctadecanoyl-sn-glycero-3-phosphocholine (DSPC), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), and a linear statistical (random) copolymer comprised of oligo (ethylene glycol) methyl ether methacrylate (OEGMA) and lauryl methacrylate (LMA). Their features were examined by light scattering techniques, fluorescence spectroscopy, and MTS assay. For the first time DSPC:DOPC:P(OEGMA-co-LMA) hybrid systems were successfully formulated and the most prominent factors influencing their thermodynamic, physicochemical, and toxicological properties were investigated. Our results indicate that self-assembly is pivotal for hybrid systems performance and is mediated via random topology of copolymer, lipid composition, hydrophilic to hydrophobic balance, and lipid to polymer ratio. Having in mind fast clinical translation, we hope this work to contribute to a design road map for efficient lipid/copolymer nanostructure development. [Display omitted] [ABSTRACT FROM AUTHOR]

The bowl‐shaped aluminum alkoxide complexes bearing N2O2 bis(phenolate)‐amine ligands having different side arms as pyridine (1), dimethyl amine (2), and diethyl amine (3) were shown to be highly efficient and well behaved in the homopolymerization and copolymerization of l‐lactide (LA) and ε‐caprolactone (ε‐CL) at 100 °C. The rates of copolymerization are similar for Complexes 1–3 where nearly full conversions were achieved in 60 h for [LA]:[CL]:[Al] ratio of 50:50:1. The minor adjustment of the side arms of the Catalysts 1–3 gave profound differences in the LA/ε‐CL copolymer sequences where tapered, gradient, and highly random structures were obtained in one system, respectively. The chelation of LA to Al metal after ring‐opening process and suitable steric hindrance of the side arms were believed to participate and saturate the aluminum metal centers giving different copolymer structures. The random LA/ε‐CL copolymer structure was confirmed by nuclear magnetic resonance and differential scanning calorimetry analysis. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1635–1644 [ABSTRACT FROM AUTHOR]

Metal oxide nanoparticle-mediated solution polymerization of aniline (ANI) with alizarin red (AR) and methyl red (MR) was carried out under different experimental conditions in the presence of FeCl3 as an oxidizing agent at 0–5 °C under nitrogen purging for 2 h. Thus, the synthesized random copolymer was characterized by FTIR, UV–visible, fluorescence emission spectroscopy, FESEM and conductivity measurement. The order of reaction was calculated for monomer and metal oxide nanoparticles variations. The FTIR spectrum showed a peak at 1462 cm−1 corresponding to the N=N stretching of MR dye in the copolymer structure. The metal oxides-mediated copolymerization of ANI with MR led to the decrease in absorbance and fluorescence emission spectroscopy due to the degradation of MR structure. The copolymerization of dyes with ANI was confirmed by GPC. The solubility test declared that the prepared copolymers are freely soluble in water. The CuO nanoparticle-mediated random copolymer showed an increase in electrical conductivity value. A plausible reaction mechanism was proposed in order to explain the experimental results obtained. [ABSTRACT FROM AUTHOR]

A novel high refractive index hybrid film was produced by hybridization of carbazole phenoxy based copolymers and titania. The random copolymer was prepared first by copolymerization of carbazole phenoxy based methacrylate(CPBM) and 3-(trimethoxysilyl)propyl methacrylate, and then a titania precursor, Ti(OBu)4 was reacted with the copolymer to form a high-refraction film through in-situ sol-gel process. The 1H NMR and FT-IR results confirmed that CPBM and the CPBM copolymer/titania hybrid materials were successfully prepared. The hybrid film made from CPBM had a high refractive index in the range 1.68 ∼ 1.77, proportional to the content of the titania precursor in the hybrid, which was higher than the film from MMA. The CPBM based hybrid solution produced a much smooth film by spin coating compared to the hybrid from MMA, which could be attributed to a low glass transition temperature of CPBM. The TGA results of the hybrid materials revealed good thermal stability. [ABSTRACT FROM AUTHOR]

Conditions were found for controlled reversible addition-fragmentation chain-transfer radical polymerization to obtain narrow-dispersity gradient methacrylic acid-methyl acrylate copolymer (Mn = 1.59 × 104). A copolymer of similar composition and molecular mass (Mn = 1.81 × 104) with random distribution of units was obtained by radical copolymerization in the presence of dodecyl mercaptan. The behavior of the gradient and random copolymers, each containing ∼14 mol % methacrylic acid units, was studied in solutions, Langmuir monolayers, and Langmuir-Blodgett films. Several ranges of the existence of associates and micelles, preserved upon transfer in a Langmuir-Blodgett film, were revealed for the narrow-dispersity copolymer at the water-air interface depending on pH of the subphase. Associates in the form of ribbon structures and molecular ensembles of nanometric size (network structure with loop-like fragments) are observed in the AFM images of Langmuir-Blodgett films of the gradient and random copolymers, respectively. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Various PMMA-ran-PTFEMA with different monomer ratios were prepared by free radical polymerization. • The surface and optical properties of PMMA could be precisely controlled through the copolymer system. • -CF 3 moiety exhibited a strong effect on diversifying the surface and optical properties by their content. Abstract Poly(methyl methacrylate) (PMMA) is a widely used polymer, but its surface properties are often not ideal for coating applications. Here, a wide range of surface and optical properties of PMMA were achieved by controlling the copolymer type, poly(trifluoroethyl methacrylate) (PTFEMA)-X, where X is the feed ratio (mol %) of trifluoroethyl methacrylate (TFEMA), where TFEMA includes hydrophobic –CF 3 moiety. Four different PTFEMA-X samples (i.e. PTFEMA-5, -10, -20, and -40) were prepared by changing the monomer ratio between MMA and TFEMA. The surface energies, surface compositions, transmittances, and refractive indices of the samples were compared to those of PMMA and PTFEMA. The results showed a linear relationship between these properties and TFEMA content, demonstrating a potential method for controlling the surface and optical properties of PMMA. This is interesting as the only difference between MMA and TFEMA is that TFEMA has –CF 3 moiety. [ABSTRACT FROM AUTHOR]

The development of polymer-based electrochromic devices (ECDs) with high stability and fast response time is of utmost importance for their effective utilization in ECD displays. In this study, we took inspiration from the random copolymer design strategy and successfully synthesized three solution-processable polymers, namely PTQ1, PTQ2, and PTQ3. These polymers were created using propylenedioxythiophene (ProDOT) as the donor unit and 5,8-dibromo-2-((2-ethylhexyl) oxy) quinoxaline (QX) as the acceptor unit, with varying feed ratios of ProDOT to QX (1:1, 2:1, and 3:1, respectively). Remarkably, all three polymers exhibited remarkably low oxidative initiation potentials and effective overpotentials, resulting in their respective ECDs displaying impressively fast response times of 1.8 s for PTQ1, and 0.9 s for both PTQ2 and PTQ3. Furthermore, these electrochromic polymers demonstrated exceptional stability, as indicated by their ability to maintain nearly 90% optical contrast even after 100,000 reversible switching cycles. This finding underscores the high stability of PTQ2 and PTQ3 when integrated into devices, highlighting their suitability for incorporation into future applications. Notably, owing to their fast response time and excellent reversibility, we were able to successfully fabricate two types of ECDs based on PTQ3: an inkjet-printed patterned ECD, as well as a larger 10 × 10 cm2 ECD. These achievements demonstrate the immense potential of the random copolymer strategy not only in the field of display technology but also in the development of smart windows. In conclusion, our research has successfully synthesized and characterized three solution-processable polymers for use in polymer-based ECDs. By employing the random copolymer design strategy, we have achieved impressive stability, fast response times, and high reversibility. These findings pave the way for the implementation of these electrochromic polymers in a wide range of applications, including displays and smart windows. [Display omitted] • Three solution-processable D-A copolymers were synthesized with different D:A ratios. • Increasing the ratio of D unit can effectively elevate the HOMO energy level and lower the oxidative initiation potentials. • The optical contrast still maintains over 90% after 100,000 reversible switching cycles. • An inkjet-printed large-area ECD was fabricated with vibrant electrochromic performance. [ABSTRACT FROM AUTHOR]

Broadband dielectric spectroscopy (BDS) is a powerful technique for studying the dielectric and ion-conductive behavior of solid polymer electrolytes (SPE). In this study a random copolymer of ethylene carbonate (EC) and ethylene oxide (EO), P(EC/EO), was used as a polymer host for SPE, and the correlation between dielectric relaxation and ionic conduction in P(EC/EO)-LiFSI electrolytes was studied. BDS measurements revealed that the DC conductivity for P(EC/EO) electrolytes is higher than for the PEC system at all salt concentrations. This is due to the much higher a-relaxation frequency, indicating that the randomly introduced EO units can provide fast segmental motion with no formation of any stable coordination structures with Li ions. FT-IR analysis indicated that the peak fraction of C = O interacting with Li ions was small, less than 10% in the 10 mol% electrolyte, but in concentrations above 40 mol% the proportion was nearly saturated at around 60–70%. A small C O-C peak interacting with Li ions appears at 1080 cm−1, but no change in peak intensity is observed, implying no formation of stable coordination structures that reduce the glass transition temperature. [ABSTRACT FROM AUTHOR]

This study describes a simple yet efficient approach for the preparation of an ionic gel that is also elastomeric in its solid-state bulk form. A series of poly(2-(diethylamino)ethyl methacrylate-co-lauryl methacrylate) P(DMAEMA-co-LMA) copolymers were synthesized first by radical polymerization. Quaternization of the PDMAEMA component in tetrahydrofuran enables the formation of supramolecular network, giving rise to an ion gel. An elastomer with an elongation at break of over 600% was obtained from the gel. The elastomer, connected by supramolecular ionic cross-links, is solvoplastic in certain solvents. The simple yet efficient approach of the formation of ion-gel and the dried elastomer allows fast preparation of both gel-like and solid-state elastic materials for various applications where recyclability is required.