Polymer Size Research Articles

Synthesis and characterization of size-tunable core-shell structural polyacrylate-graft-poly(acrylonitrile-ran-styrene) (ASA) by pre-emulsion semi-continuous polymerization

The core-shell polymeric polyacrylate-graft-poly(acrylonitrile-ran-styrene)(ASA) has been explored for the polymer industry due to its excellent properties. However, it has been a longstanding challenge to synthesize large size-tunable particles by the conventional batch polymerization. In this paper, an accurate method, i.e. pre-emulsion semi-continuous polymerization, is applied to prepare ASA polymeric particles, which makes a series ofdifferent particle sizes (100–450 nm) of the crosslinked poly(butyl acrylate) (PBA) inner core coated with a hard shell using the poly(acrylonitrile-ran-styrene) (AS) copolymer. Specifically, the feed modes and proportion of seedare investigated to tune the particle size.The results show that the PBA seed microsphere in pre-emulsion semi-continuous polymerization is enlarged by accurate feed rate, but not in batch polymerization. A possible mechanism for the growth of the PBA core is proposed that secondary particles from homogeneous nucleation in semi-continuous feed mode is less than that of batch mode, which attenuate the impact on the growth of core particle. The size and morphology of resulting particles are characterized using various analytical techniques including the transmission electron microscopy (TEM), the scanning electron microscopy (SEM) and the dynamic light scattering (DLS). Core-shell separates phase corresponding to different glass transition temperatures is evaluated using differential scanning calorimeter (DSC) analyses indirectly. Moreover, the mechanical properties including impacts and tensile strengths are also analyzed. This study thus highlights a detailed strategy to tune polymeric particles related to different properties and the nucleating mechanism of seed emulsion polymerization that governs structure, particle size and distribution of ASA polymer with a bespoke structure for various application.

High strength PLGA/Hydroxyapatite composites with tunable surface structure using PLGA direct grafting method for orthopedic implants

Poly (Lactic-co-Glycolic Acid) (PLGA) based bio-composites for orthopedic implants are becoming more important as surgical techniques develop. Enhancers such as hydroxyapatite (HA) are used to enhance the biocompatibility and bone formation. Studies on HA surface treatment have been proposed to enhance the bonding force between particles HA and PLGA. Conventional monomer-based grafting techniques have limitations in copolymer grafting and improving mechanical strength of composites. In this study, PLGA can be directly grafted to HA surface in polymer state using melt grafting with transesterification. With this method, the grafting efficiency of PLGA is improved compared to previous studies. The grafting efficiency of PLGA was analyzed and the structure at the surface was confirmed. It was confirmed that a polymer having a large molecular weight can be grafted on the HA surface when PLGA is in an abundant state by indirectly analyzing the size of the grafting polymer through molecular weight evaluation. A composite materials using PLGA-g-HA prepared under optimized conditions have tensile strengths increased by more than doubled compared with a n-HA blended composite. The direct grafting technique of polymer was found to be effective in forming the anchoring structure between HA particles and PLGA.

Effect of Polymer Chemistry on Chain Conformations in Hairy Nanoparticle Assemblies.

Matrix-free, polymer-grafted nanoparticles, called hairy nanoparticle assemblies (aHNPs), have proven advantageous over traditional nanocomposites, as good dispersion and structural order can be achieved. Recent studies have shown that conformational changes in the polymer structure can lead to significant enhancements in the mechanical properties of aHNPs. To quantify how polymer chemistry affects the chain conformations in aHNPs, here we present a comparative analysis based on coarse-grained molecular dynamics simulations. Specifically, we compare the chain conformations in an anisotropic cellulose nanoparticle grafted to four common polymers with distinct chemical groups, fragility, and segmental structures, that is, poly(methyl methacrylate) (PMMA), polystyrene (PS), polycarbonate (PC), and polybutadiene (PB). We observe that semiflexible glassy polymers such as PMMA and PS have a higher critical chain length (Ncr), the transition point where the polymer conformation changes from concentrated to semidilute brush regime. Flexible rubbery polymers (PB) can overcome the Ncr barrier at relatively lower molecular weights. We have used theoretical scaling laws based on Daoud-Cotton theory to uncover a direct correlation between empirical constants and physical parameters, such as persistence length and monomer excluded volume. Furthermore, we carried out a systematic study to understand the role of backbone rigidity and side-group size of polymer, and it revealed that the backbone rigidity significantly affects Ncr but the side-group size doesn't seem to have an appreciable effect on Ncr. We find that normalization of the monomer radial distribution curves using Ncr and other key molecular parameters collapses the curves for 110 distinct model aHNP systems studied. Our work paves the way for systematic quantification of these molecular design parameters to accelerate the design of polymer-grafted nanoparticle assemblies in combination with universal scaling relationships.

Synthesis and characterization of thermally stable bio-based poly(ester amide)s from sustainable feedstock

Aromatic poly(ester amide)s comprising of α-amino acids and lignin-derived building blocks were synthesized and their thermal properties assessed. The polymers, which were prepared by melt polycondensation with p-toluenesulfonic acid as the catalyst, all possessed high thermal stability in N2; the onsets of thermal degradation (Td onset) were >320 °C, the percent char yields ranged from 40 to 65% at 800 °C, and the glass transition temperatures (Tg) ranged from 136 °C–238 °C. Remarkably, the polymers were also thermally stable in air, with the Td onsets >330 °C and Td 50% >520 °C. Interestingly, the size of the R-group on the amino acids greatly affected the Tg, but only minimally affected the Td; perhaps due to the variation in polymer size. Wide angle x-ray diffraction measurements (WAXS) revealed semi-crystalline polymers, with similar diffraction patterns for all the polymers. The polymers mostly maintain their thermal stability after being subjected to various pH media for 6 days at 50 °C. Altogether, these characteristics make our bio-based PEAs worthwhile candidates for continued investigation as alternatives to petrochemical-derived thermoplastics for high performance materials.

Microplastic particles reduce reproduction in the terrestrial worm Enchytraeus crypticus in a soil exposure

Terrestrial environments are subject to extensive pollution by plastics and, based on the slow degradation of plastics, are likely to act as long term sinks for microplastic debris. Currently the hazards of microplastics in soil and the potential impacts on soil organisms is poorly understood. Particularly the role of particle characteristics, such a size or polymer type, in dose-response relationships for microplastics is not known. The aim of this study was to assess the ingestion and toxicity of nylon (polyamide) particles, in three different size ranges, to Enchytraeus crypticus in a soil exposure. Effects were also compared with those of polyvinyl chloride (PVC) particles, in a single size range. Nylon particle ingestion was confirmed using fluorescence microscopy, with greatest ingestion for particles in the smallest size range (13–18 μm). To investigate how particle size affected survival and reproduction, E. crypticus were exposed to nylon particles in two well-defined size ranges (13–18 and 90–150 μm) and concentrations of 20, 50, 90 and 120 g/kg (2–12% w/w). An intermediate nylon size range (63–90 μm) and a larger sized PVC particle (106–150 μm), both at 90 g/kg, were also tested. Survival was not affected by either of the polymer types or sizes. Reproduction was significantly reduced, in a dose-dependent manner, by the nylon particles at high exposure concentrations (>90 g/kg). Smaller size ranges (13–18 μm) had a greater effect compared to larger size ranges (>63 μm), with a calculated EC50 for the 13–18 μm size range of 108 ± 8.5 g/kg. This greater hazard could be qualitatively linked with the ingestion of a greater number of smaller particles. This study highlights the potential for toxic effects of plastics in small size ranges to soil organisms at high exposure concentrations, providing understanding of the hazards microplastics may pose in the terrestrial environment.

Hard-wall entropic effect accelerates detachment of adsorbed polymer chains.

Many previous studies of unbinding kinetics have focused on a two-state model, with fully bonded and free states, which may not extend to more complicated biopolymer dynamics involving other reactions. Here we address the kinetic rate of this process at the segment level, as it is influenced by a growing dangling end of the chain. We use the mean first-passage time approach and treat the polymer as a chain attached to a wall through a succession of spring potentials, with two distinct regions of bonded and free segments. The interaction between the wall and free-moving chain end adds an entropic repulsion to this process. We estimate the average monomer detachment rate K as a function of the free dangling length L. For a flexible polymer, we find an acceleration factor in the average detachment rate depending on L and the details of the spring bond; when L is long, this factor is a simple ratio of its breaking distance to the natural bond length. For a semiflexible filament, we examine the regime where L is shorter than persistence length L_{p}, as the limit opposite to that of the flexible chain. An enhancing factor also appears, speeding up the filament unbinding when the free length grows; for a long rigid rod, this factor becomes two, independently of the bond details. We also examine the total unbinding time of an irreversible detaching process by integrating (1/K) over polymer length and discover that its power-law scaling with chain length is smaller than one, over the commonly seen range of polymer size.

Added-value porous materials for controlled thymol release obtained by supercritical CO2 impregnation process

This study explores utilization of biodegradable and biocompatible polymers for controlled release of natural bioactive substance. For that purpose, poly(ε-caprolactone) (PCL) beads, cellulose acetate (CA) film, and poly lactic- co-glycolic acid (PLGA) flakes were impregnated with thymol by employing environmentally friendly process of supercritical carbon dioxide (scCO2) impregnation. At selected pressure and temperature, prolongation of operating time increased thymol loading. Pure scCO2 did not affect CA film with average pore diameter of approximately 3 µm, while it enabled change of PCL beads and PLGA flakes into foams with average pore diameter approximately 175 µm and 87 µm, respectively. Additionally to scCO2, thymol acted as a plasticizer increasing pore size of polymers up to three times. Kinetic of thymol release from selected samples was tested using phosphate buffer saline at 37°C and successfully described with Korsmeyer–Peppas, zero-order, first-order, and Higuchi models. The suggested method of PCL, CA, and PLGA supercritical impregnation led to development of porous, solvent free, added-value materials that release thymol in a controlled manner from 5 h to several days.

Purification of monoclonal antibodies in a stirred cell with polyethyleneimine‐modified polyethersulfone ultrafiltration membrane

AbstractBACKGROUNDCharged ultrafiltration membranes combined with optimal operating conditions can be used to enable monoclonal antibody purification. Positively charged ligands bound to the membrane surface can significantly contribute to the adsorption of negatively charged proteins and enhance the purification process.RESULTSIn this work, commercially available 500 kDa polyethersulfone ultrafiltration membranes were modified by sulfonation, followed by deposition of polyethyleneimine (PEI) and crosslinking with butanedioldiglycidylether. Polymer molecules of 2 and 10 kDa were used to evaluate how polymer size influences the fractionation of a harvested Chinese hamster ovary cell culture fluid containing a monoclonal antibody by ultrafiltration at different operational pH values. The precursor and modified membranes were analyzed by X‐ray photoelectron spectroscopy, which confirmed the successful modification of membranes. Nitrogen analysis showed the presence of amine groups, clearly confirming immobilization of PEI onto the membrane surface. When 10 kDa PEI is chosen for membrane modification, the intensity of this signal increases, as predicted for a higher‐molecular‐weight polymer. Ultrafiltration performance indicators (fluxes, transmissions, yields) were determined and compared for the modified and precursor membranes, with the PEI‐derived membranes showing ability for pH modulation of selectivity.CONCLUSIONHigh purities were consistently observed at pH 9 owing to a simultaneous decrease in the transmission of soluble protein and increase in both IgG transmission and adsorptive capacity of the membranes. A single‐step process at pH 9 renders a permeate with an antibody purity of 96%, using a non‐crosslinked membrane modified with 10 kDa PEI. © 2019 Society of Chemical Industry

Increased Polymer Diffusivity in Thin-Film Confinement

The behavior of polymer melts under planar confinement was investigated using molecular dynamics simulations. Polymers with a range of lengths, from unentangled to highly entangled (N = 25–400), were confined between two discrete-bead parallel walls to create thin films with thicknesses (h = 3.5–40σ, where σ is the unit length) ranging from much larger to much smaller than the polymer size. These simulations were used to measure polymer-chain conformations, entanglement densities, and center-of-mass diffusion, and the results were compared with previous simulations of polymer melts under cylindrical confinement. Changes to the entanglement density and radius of gyration in thin films follow the same behavior as in cylindrical confinement: decreased entanglements per chain, decreased Rg perpendicular to the confining wall, and increased Rg parallel to the confining wall, though the deviations from bulklike conformations are smaller. Despite similarities in conformation and entanglement behavior between thin-film and cylindrical confinements, the diffusion behavior differs. Under planar confinement, the diffusion coefficient increases monotonically up to 6 times the bulk diffusivity with decreasing film thickness, while it behaves nonmonotonically in cylinders. This is due to the increased degrees of freedom afforded to the polymer chains in a thin film compared to those in a cylinder, allowing chains to diffuse around one another rather than through, as found in cylindrical confinement. Normalized diffusion coefficients, Dnorm, can be well described by a master curve with an exponential dependence on confinement after scaling Dnorm by a thickness-dependent term.

The relaxation times of unentangled polymer melts with different molecular architectures

Monte Carlo algorithm is adopted to simulate linear, ring, H-shaped and three-arm star polymer melts, and the dependence of relaxation times defined by different methods on polymer size is investigated. Statistical and dynamic properties of several unentangled polymer melts are also revealed for comparison. It is obviously that the numerical difference is small when relaxation times defined by the ratio of maximum mean-square end-to-end distance of several polymers as a function of corresponding mean-square radius of gyration, and data for different architectures collapse onto a universal curve in unentangled regime. The relaxation times for several polymer exhibits weak dependence on architecture. However, the special relationship cannot be found through the relaxation times defined by the position of the intersection of g2 and g3, end-to-end correlation function and mean-square radius of gyration, with stronger architecture dependence. The correctness of the relationship is also reflected by mean-square monomer displacement. The result provides a new understanding of the correlation between relaxation time and polymer size.

How are the thermal properties of polypropylene/graphene nanoplatelet composites affected by polymer chain configuration and size of nanofiller?

The leading purpose of this work was to broaden the current knowledge about the impacts of various chain configurations of polypropylene (PP), i.e., linear and branched form, on the thermal properties (thermal stability, thermal conductivity, crystallinity, thermal mechanical properties) of PP nanocomposites reinforced by graphene nanoplatelet (GnP) particles. The utilization of GnP with different particle size gave us good information about the impacts of filler's dimension on the thermal properties as well. Regardless of the PP type, EC1500-filled (small size GnP) composites showed higher storage modulus in the dynamic mechanical analysis. With respect to DSC results, incorporation of GnP, particularly GnP with smaller particles, led to a striking increment in crystallization temperature and crystallinity, and nucleating efficiency of GnP in linear PP-based composites was higher. The employment of GnP brought about an improvement in degradation temperature and thermal stability of nanocomposites, and smaller GnP was more effective in this context. However, due to its higher aspect ratio, EC100 GnP (large size GnP) could enhance thermal conductivity more satisfactory, specifically in linear PP-based samples.

Engineering the Pore Size of Pillared-Layer Coordination Polymers Enables Highly Efficient Adsorption Separation of Acetylene from Ethylene.

The pore size of adsorbents plays a vital role in determining the overall separation performance of gas separation and purification by adsorption. In this work, the pore apertures of the coordination pillared layer (CPL) was systematically controlled by adjusting the length of pillared ligands. We used pyrazine, 4,4'-bipyridine, and 1,2-di(4-pyridyl)-ethylene with increased length to synthesize CPL-1 (L = pyrazine), CPL-2 (L = 4,4'-bipyridine), and CPL-5 [L = 1,2-di(4-pyridyl)-ethylene], respectively. The aperture size of these CPLs varies from 4 to 11 Å: CPL-1 (4 × 6 Å2), CPL-2 (9 × 6 Å2), and CPL-5 (11 × 6 Å2). Among the three frameworks, CPL-2 exhibits the highest C2H2 uptake at ambient conditions as it has moderate pore size and porosity. However, CPL-1 has the best separation performance in the breakthrough experiments with binary gas mixture of C2H2/C2H4, thanks to the optimal pore size nearly excluding C2H4, which is only observed in the state-of-the-art UTSA-300a so far. The DFT calculations were carried out to elucidate the specific adsorption sites for both acetylene and ethylene among these frameworks. The modeling results suggest that binding strength is highly related to aperture size and that CPL-1 shows the highest adsorption selectivity owing to the optimal pore size. This work demonstrates that engineering pore size enables us to fabricate the highly efficient metal-organic framework (MOF)-based adsorbents for specific gas separation on the basis of the isoreticular chemistry.

Morphology and thermodynamics of polymers with monofunctional hydrogen bonding ends in dilute and semidilute concentration.

Rheological properties of supramolecular polymers (SMPs) depend on their equilibrium structure including the size, the number, and the topology of aggregates. A polymer with a hydrogen bonding (H-bonding) motif at both ends is one widely used precursor to build SMPs. Due to the complex interplay between chain stiffness, H-bonding interaction, polarity along a chain, and polymer conformational entropy, it is difficult to theoretically predict the structure of SMPs. In this work we investigate thermodynamics of SMPs with H-bonding ends in a wide range of densities. A replica exchange stochastic approximation Monte Carlo method with coarse-grained models for polyethylene and polybuthylene glycols is used. Our simulation shows that SMPs have two morphological transition lines with increasing temperature, a ring-linear transition, and a linear-free chain transition. The latter is a thermodynamic transition and turns out to be continuous. Comparing the two different spacers, we find that ring-linear transition temperatures differ from each other at the constant volume fraction due to different looping probabilities, which can be calculated from the average polymer size by mean field. However, the linear-free chain transition temperatures are similar because the entropic penalty to form a hydrogen bond mainly depends on the probability of finding H-bonding groups in a system, which is the same for both systems at a given volume fraction.

Enhancement of electroconductivity and percolation threshold by the morphology of dielectric network in segregated polymer/nanocarbon composites

Conductivity and percolation threshold of segregated polymer composites were investigated for different spatial configurations of polymer networks and types of nanocarbon fillers. It was concluded, that the influence of morphology of fillers becomes insignificant compared with the influence of morphology of polymer network on the transport properties of segregated composites. Ordered spatial distribution of polymer grains causes lower percolation threshold than their random distribution due to the preventing of a formation of random filler puddles, excluded from the conductive network. If polymer network distributes disorderly, the best way to eliminate these puddles is careful control of the ratio between sizes of polymer and filler particles. Due to the high cost and difficulties in the dispersion of expensive high aspect ratio fillers, it is much more favorable to regulate transport properties of segregated composites by the morphology of polymer network instead of filler one. Our numerical results were carefully compared with available experimental data.

Controllable Preparation and Application of Quercetin Molecularly Imprinted Polymer

The quercetin molecularly imprinted polymer microspheres were prepared by reversible addition-fragmentation chain transfer free radical polymerization combined with precipitation method (RAFTPP) with the dibenzyl trithiocarbonate (DBTTC) as RAFT reagent and quercetin as template molecule. The effects of solvents and cross-linking agent on the morphology and size of polymers were investigated, and the polymers were preliminarily screened by scanning electron microscope. The adsorption experiment and adsorption model analysis were carried out on the molecularly imprinted polymers (R-MIP) prepared under optimal condition and on the molecularly imprinted polymers prepared with a traditional precipitation polymerization (T-MIP). Consequently it was determined that, QR-MIP max was 37.71 mg g−1 and QT-MIP max was 29.61 mg g−1. The results showed that the R-MIP had a good adsorptive property and was obviously superior to T-MIP. R-MIP was used as solid-phase extraction filler in combination with the HPLC method to conduct enrichment, separation and measurement of the quercetin in honeysuckle and clove leaves, which effectively removed the matrix interference and the recovery rate of this method was 93.8–102.9%.

Influence of NaCl on the polymerization of vinyl monomers by the suspension process

The production of artificial polymers is, today, one of themost important activities of the chemical industry, polymersare widely used in everyday life, as, there are different types of polymers, they can be used for different uses. These polymeric materials have unique mechanical, physical and chemical properties, which most other materials do not possess, not to mention that its cost is lower than the other materials. The present research work focuses on the determination of optimal operating conditions for the polymerization of styrene and methyl methacrylate in a Batch reactor, as well as the influence of inorganic salt in this case NaCl in the performance of reaction and in the size of the material polymer, through the process of suspension using a synthetic route of polymerization by radical free conventional (FRP), where viscometry to the polymeric material testing was performed for this way characterize it, and to determine factors of interest such as the molecular weight, etc.

Cross-linker mediated compaction and local morphologies in a model chromosome

Chromatin and associated proteins constitute the highly folded structure of chromosomes. We consider a self-avoiding polymer model of the chromatin, segments of which may get cross-linked via protein binders that repel each other. The binders cluster together via the polymer mediated attraction, in turn, folding the polymer. Using molecular dynamics simulations, and a mean field description, we explicitly demonstrate the continuous nature of the folding transition, characterized by unimodal distributions of the polymer size across the transition. At the transition point the chromatin size and cross-linker clusters display large fluctuations, and a maximum in their negative cross-correlation, apart from a critical slowing down. Along the transition, we distinguish the local chain morphologies in terms of topological loops, inter-loop gaps, and zippering. The topologies are dominated by simply connected loops at the criticality, and by zippering in the folded phase.

Modified properties of alternan polymers arising from deletion of SH3-like motifs in Leuconostoc citreum ABK-1 alternansucrase

Alternansucrase (ALT, EC 2.4.1.140) catalyses the formation of an alternating 〈-1, 3/1, 6-linked glucan, with periodic branch points, from sucrose substrate. Beyond the catalytic domain, this enzyme harbours seven additional C-terminal SH3-like repeats. We herein generated two truncated alternansucrases, possessing deletions of three and seven adjacent SH3 motifs, giving Δ3SHALT and Δ7SHALT. Δ3SHALT and Δ7SHALT exhibited kcat/Km for transglycosylation activity 2.3- and 1.5-fold lower than wild-type ALT (WTALT), while hydrolysis was detected only in the truncated ALTs, oligosaccharide patterns and polymer glycosidic linkage were similar to that of WTALT. The viscosities of ALT polymers increase by ˜100-fold at 15% (w/v), with gel-like states formed at 12.5, 15.0, and 20.0% (w/v) produced by polymer from WTALT, Δ3SHALT, and Δ7SHALT, respectively. The average nanoparticle sizes of Δ3SHALT and Δ7SHALT polymers were 80 nm, compared to 90 nm from WTALT. In conclusion, even relatively subtle differences in the structure of ALT-produced alternan give rise to profound impact on the glucan polymer physicochemical properties.

Dissecting the Dual Nature of Hyaluronan in the Tumor Microenvironment.

Hyaluronan (HA) is a glycosaminoglycan with a simple structure but diverse and often opposing functions. The biological activities of this polysaccharide depend on its molecular weight and the identity of interacting receptors. HA is initially synthesized as high molecular-weight (HMW) polymers, which maintain homeostasis and restrain cell proliferation and migration in normal tissues. These HMW-HA functions are mediated by constitutively expressed receptors including CD44, LYVE-1, and STABILIN2. During normal processes such as tissue remodeling and wound healing, HMW-HA is fragmented into low molecular weight polymers (LMW-HA) by hyaluronidases and free radicals, which promote inflammation, immune cell recruitment and the epithelial cell migration. These functions are mediated by RHAMM and TLR2,4, which coordinate signaling with CD44 and other HA receptors. Tumor cells hijack the normally tightly regulated HA production/fragmentation associated with wound repair/remodeling, and these HA functions participate in driving and maintaining malignant progression. However, elevated HMW-HA production in the absence of fragmentation is linked to cancer resistance. The controlled production of HA polymer sizes and their functions are predicted to be key to dissecting the role of microenvironment in permitting or restraining the oncogenic potential of tissues. This review focuses on the dual nature of HA in cancer initiation vs. resistance, and the therapeutic potential of HA for chemo-prevention and as a target for cancer management.

Self-Assembly of Polymer-Encased Lipid Nanodiscs and Membrane Protein Reconstitution.

The absence of detergent and curvature makes nanodiscs excellent membrane mimetics. The lack of structural and mechanistic model of polymer-encapsulated lipid nanodiscs limits their use in the study of the structure, dynamics, and functions of membrane proteins. In this study, we parameterized and optimized the coarse-graining (CG) bead mapping for two differently charged and functionalized copolymers, containing styrene-maleic acid (SMAEA) and polymethacrylate (PMAQA), for the Martini force-field framework and showed nanodisc formation (<8 nm diameter) on a time scale of tens of microseconds using molecular dynamics (MD) simulations. Structural models of ∼2.0 or 4.8 kDa PMAQA and ∼2.2 kDa SMAEA polymer-based lipid nanodiscs highlight the importance of the polymer chemical structure, size, and polymer-lipid ratio in the optimization of the nanodisc structure. The ideal spatial arrangement of polymers in nanodiscs, nanodisc size, and thermal stability obtained from our MD simulation correlates well with the experimental observations. The polymer-nanodiscs were tested for the reconstitution of single-pass or multipass transmembrane proteins. We expect this study to be useful in the development of novel polymer-based lipid nanodiscs and for the structural studies of membrane proteins.