Glycol Methyl Ether Acrylate Research Articles

Constructing the high-efficiency “celluveyor conveyor” transport systems in membranes by IL@ZIF-8 for efficient CO2/CH4 separation

Inspired by the high-efficiency transport systems combined the “conveyor” transport pathways with the “celluveyor” transport pathways, the ionic liquid imide modified ZIF-8 (IL@ZIF-8) was prepared as a filler and incorporated into the self-polymerization-confined Pebax/polyethylene glycol methyl ether acrylate matrix (SPM) to prepare mixed matrix membranes (MMMs) for efficient CO2/CH4 separation. The incorporated IL@ZIF-8 can construct the high-efficiency “celluveyor conveyor” transport systems that consisted of the “celluveyor” transport pathways and the “conveyor” transport pathways, and it played important roles in MMMs. Therein, the “celluveyor” transport pathways can be constructed with the help of CO2 carriers (Zn2+) in oriented and ordered pore channels of IL@ZIF-8, contributing to promoting rapid CO2 transport in multiple direction. IL was uniformly distributed on ZIF-8, and it acted as “binder” between adjacent ZIF-8 in IL@ZIF-8. IL in IL@ZIF-8 can adsorb CO2 molecules as a consequence of its strong chemical affinity for CO2, and the “conveyor” transport pathways can be constructed with the help of CO2 carriers ([Tf2N]-) in IL for rapid CO2 transport between the adjacent ZIF-8, improving CO2 separation performance of MMMs. Consequently, it was possible to enhance the performance of CO2 separation by constructing the high-efficiency “celluveyor conveyor” transport systems in SPM/IL@ZIF-8 MMMs. Therefore, SPM/IL@ZIF-8 MMMs were endowed with the excellent CO2 separation performance. It showed an enhanced permeability for CO2, which increased by 96.9 %, and a better CO2/CH4 selectivity, which improved by 56.6 %, when compared to the performance of the pure SPM membrane. It implied that the constructed high-efficiency “celluveyor conveyor” transport systems in MMMs were a promising strategy for efficient CO2 separation.

FFF/FDM 3D-Printed Solid Polymer Electrolytes Based on Acrylonitrile Copolymers for Lithium-Ion Batteries.

Lithium-ion batteries (LIBs) are essential in modern electronics, particularly in portable devices and electric vehicles. However, the limited design flexibility of current battery shapes constrains the development of custom-sized power sources for advanced applications like wearable electronics and medical devices. Additive manufacturing (AM), specifically Fused Filament Fabrication (FFF), presents a promising solution by enabling the creation of batteries with customized shapes. This study explores the use of novel poly(acrylonitrile-co-polyethylene glycol methyl ether acrylate) (poly(AN-co-PEGMEA)) copolymers as solid polymer electrolytes for lithium-ion batteries, optimized for 3D printing using FFF. The copolymers were synthesized with varying AN:PEGMEA ratios, and their physical, thermal, and electrochemical properties were systematically characterized. The study found that a poly(AN-co-PEGMEA) 6:1 copolymer ratio offers an optimal balance between printability and ionic conductivity. The successful extrusion of filaments and subsequent 3D printing of complex shapes demonstrate the potential of these materials for next-generation battery designs. The addition of succinonitrile (SCN) as a plasticizer significantly improved ionic conductivity and lithium cation transference numbers, making these copolymers viable for practical applications. This work highlights the potential of combining polymer chemistry with additive manufacturing to provide new opportunities in lithium-ion battery design and function.

Cross-Linked Composite Solid Polymer Electrolyte Doped with Li6.4La3Zr1.4Ta0.6O12 for High Voltage Lithium Metal Batteries.

Composite solid polymer electrolytes (CSPEs) are safer alternatives to liquid electrolytes and excellent candidates for high-voltage solid-state batteries. However, interfacial instabilities between the electrodes and CSPEs are one of the bottlenecks in pursuing these systems. In this study, a cross-linked CSPE was synthesized based on polypropylene carbonate, polyethylene glycol methyl ether acrylate, polyethylene glycol diacrylate with additives including lithium bis(trifluoromethane)sulfonimide salt, and tantalum-doped lithium lanthanum zirconium oxide (LLZTO). Mass fractions of 10, 20, and 40% LLZTO were added to the CSPE matrix. In a symmetric cell, lithium plating and stripping revealed that the interface between the lithium metal anode and CSPE with 10% of the LLZTO (CSPE-10LLZTO) shows the most stable interface. The CSPE-10LLZTO sample demonstrated high flexibility and showed no degradation over 800 h of cycling at varying current densities. The ionic conductivity for the CSPE-10LLZTO sample at 40 °C was 6.4 × 10-4 S/cm. An all-solid-state full cell was fabricated with LiNi0.5Mn0.3Co0.2O2 as the cathode, CSPE-10LLZTO as the electrolyte and separator, and Li metal as the anode, delivering approximately 140 mAh/g of capacity. Differential scanning calorimetry measurements on CSPE-xLLZTO showed high miscibility and the elimination of crystallinity. Raman spectroscopy revealed uniformity in the structure. These findings demonstrate the capability of the CSPEs to develop high-voltage solid-state lithium metal batteries.

Synthesis and Mechanistic Investigation of an Amphiphilic Polymer in Enhancing Extra-Heavy Oil Recovery via Viscosity Reduction.

When applied to extra-heavy oil, conventional polymer surfactants exhibit poor efficacy in reducing viscosity and have limited adaptability. In this work, a novel amphiphilic polymer named PAADB was prepared by incorporating 2-acryloylamino-2-methyl-1-propanesulfonic acid (AMPS), benzyldimethyl [2-[(1-oxoallyl) zoxy] propyl] ammonium chloride (DML), and poly(ethylene glycol) methyl ether acrylate (BEM) into the main chain of acrylamide through free radical polymerization. PAADB exhibited outstanding interfacial activity, water-phase thickening ability, and emulsifying performance. The critical micelle concentration of PAADB was approximately 2500 mg/L, with a viscosity of 84.69 mPa·s at 50 °C. Additionally, interfacial tension experienced a notable decrease from 46.53 to 14.56 mN/m. At an optimal concentration of 4000 mg/L, PAADB reduced the viscosity of extra-heavy oil by over 92% across various temperatures and by more than 93% for different types of extra-heavy oil. PAADB demonstrated excellent emulsification ability and emulsion stability, effectively dispersing crude oil to create water-in-oil droplets measuring 35.33 μm in size. Meanwhile, molecular dynamics simulations further unveiled the viscosity reduction mechanism of PAADB. The hydrophilic groups within PAADB molecules are regularly distributed on the water interface, while the hydrophobic groups infiltrate the oil molecules to form a stable interfacial film. PAADB and asphaltene spontaneously form a sandwich structure, reducing intermolecular forces and disrupting the interlayer structure of asphaltene molecules. In general, this novel amphiphilic polymer demonstrates broad applicability and potential in extra-heavy oil recovery, providing valuable insights for the development of new heavy oil viscosity reducers (HOVRs).

A General Approach for Photo-Oxidative Degradation of Various Polymers.

The escalating demand for plastics has resulted in a surge of plastic waste worldwide, posing a monumental environmental challenge. To address this issue, a versatile photo-oxidative degradation method applicable to seven distinct polymer families is proposed, comprising poly(isobutyl vinyl ether) (PIBVE), poly(2,3-dihydrofuran) (PDHF), poly(vinyl acetate) (PVAc), poly(n-butyl acrylate) (PBA), poly(methyl acrylate) (PMA), poly(vinyl chloride) (PVC), poly(dimethyl acrylamide) (PDMA), poly(ethylene oxide) (PEO), poly(oligo(ethylene glycol) methyl ether acrylate) (PEGMEA), and even poly(methyl methacrylate) (PMMA). This method employs photo-mediated hydrogen atom transfer (HAT) followed by oxidation to promote polymer degradation. This reaction is carried out under aerobic condition in the presence of iron trichloride (FeCl3) as a photocatalyst in combination with low-intensity purple light irradiation. The process can degrade up to 97% of the polymer in less than 3 h. This degradation process can be easily controlled by switching the light off, which allows for precise modulation of the degradation rate, enhancing the effectiveness of the method. Overall, this method provides a sustainable method for degrading various polymer types with low energy input.

Influence of Polymer Side Chain Size and Backbone Length on the Self-Assembly of Supramolecular Polymer Bottlebrushes.

Hydrogen bonds are a versatile tool for creating fibrous, bottlebrush-like assemblies of polymeric building blocks. However, a delicate balance of forces exists between the steric repulsion of the polymer chains and these directed supramolecular forces. In this work we have systematically investigated the influence of structural parameters of the attached polymers on the assembly behaviour of benzene trisurea (BTU) and benzene tris(phenylalanine) (BTP) conjugates in water. Polymers with increasing main chain lengths and different side chain sizes were prepared by reversible addition-fragmentation chain-transfer (RAFT) polymerization of hydroxyethyl acrylate (HEA), tri(ethylene glycol) methyl ether acrylate (TEGA) and oligo(ethylene glycol) methyl ether acrylate (OEGA). The resulting structures were analyzed using small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Both BTU and BTP formed fibres with PHEA attached, but a transition to spherical morphologies was observed at degrees of polymerisation (DP) of 70 and above. Overall, the main chain length appeared to be a dominating factor in inducing morphology transitions. Increasing the side chain size generally had a similar effect but mainly impeded any aggregation as is the case of POEGA. Interestingly, BTP conjugates still formed fibres, suggesting that the stronger intermolecular interactions can compensate partially for the steric repulsion.

Gem-bisphosphonic acid-based double hydrophilic block copolymers: RAFT synthesis and comparative assembly with gadolinium ions for the formation of MRI contrast agents

The synthesis of double hydrophilic block copolymers (DHBCs) with one block containing bisphosphonic acid groups was performed by aqueous RAFT polymerization with two approaches, either starting from a PEO-based macro-chain transfer agent (macro-CTA) or by chain extension of a RAFT-capped bisphosphonic acrylate homopolymer with oligo(ethylene glycol) methyl ether acrylate (OEGA). By complexation with gadolinium and europium ions, these polymers are prone to form hybrid polyionic complexes (HPICs) as evidenced by mono- and multi-angle DLS, TEM and luminescence measurements. The obtained HPICs showed better chemical stability at low pH values compared to previously reported counterparts based on carboxylic and monophosphonic acid groups (i.e., PEO-b-PAA and PEO-b-PVPA respectively). Due to their high relaxivity values, the proposed HPICs show potential as contrast agents for magnetic resonance imaging (MRI).

An orthogonal approach for the synthesis of graft copolymers: Visible light induced free radical polymerization and iniferter processes

Graft copolymers with polystyrene main and poly(ethylene glycol) methyl ether acrylate side chains are synthesized via an orthogonal approach combining visible light induced free radical polymerization and iniferter processes. The method relies on a deliberately designed, double functional monomer, 2,2,2-(triphenylethyl)styrene (TPES), containing both polymerizable and iniferter units.

Efficient self healable blended cationic and anionic poly(ionic liquids) under ambient conditions

AbstractPoly(ionic liquid)‐based self‐healable electrolytes are getting tremendous attention owing to their quick self‐healing ability at ambient conditions without external stimulus, prominent safety, high mechanical strength, appreciably good conductivity, and no electrolyte leakage. Ionic interactions are much stronger and more dynamic, capable of imparting faster healing ability to the electrolyte. To exploit ionic interactions and non‐covalent hydrogen bonding simultaneously for faster self‐healing at ambient conditions. In the present work, free radical promoted copolymerization of 3‐methyl‐1‐vinylimidazolium iodide and sodium 4‐vinyl benzenesulfonate (VMeImI/SS) with poly(ethylene glycol) methyl ether acrylate and ureidopyrimidinone methacrylate to obtain cationic poly (PEG‐UPy‐Im) and anionic poly (PEG‐UPy‐SS) poly ionic liquid (PIL), respectively, as polymer electrolytes (PEs) have been achieved. The complete structural analysis of the copolymers by FTIR, 1H NMR, 13C NMR, DOSY‐NMR, and GPC was done. The ionic conductivity and self‐healing properties of the synthesized PEs, poly (PEG‐UPy‐Im) and poly (PEG‐UPy‐SS) were investigated, which gave encouraging results. For further enhancement of hydrogen bonding and ionic interactions, poly (PEG‐UPy‐Im) and poly (PEG‐UPy‐SS) were blended in the ratio of 1:1, referred to as poly (Im‐SS), a binary blend, as a self‐healable oppositely charged polyelectrolyte. Poly(Im‐SS) exhibited self‐healing behavior in 15 min and 5 min at 25 and 60°C, respectively, without any external stimulus. Poly(Im‐SS) also exhibited exceptionally high ionic conductivity of 2.04 × 10−5 and 11.48 × 10−5 Scm−1 at 30 and 80°C, respectively. This unique approach of blending two oppositely charged PEs to create a binary blend has improved ionic conductivity and self‐healing capabilities. Because a poly‐ionic network forms in poly(Im‐SS) as a binary blend, the physical and chemical properties in terms of mechanical and thermal stability as well as water contact angle point to a synergistic effect of ion–ion, ion–dipole, and quadruple Hbonding. Thus, the designed copolymer electrolytes and their blend, present a new perspective to develop innovative and rapid self‐healable polyelectrolytes with significant ionic conductivity for advanced electrochemical devices such as fuel cells, batteries, and supercapacitors.

PH-Responsive Amphiphilic Triblock Fluoropolymers as Assemble Oxygen Nanoshuttles for Enhancing PDT against Hypoxic Tumor.

Photodynamic therapy (PDT) is a cancer treatment strategy that utilizes photosensitizers to convert oxygen within tumors into reactive singlet oxygen (1O2) to lyse tumor cells. Nevertheless, pre-existing tumor hypoxia and oxygen consumption during PDT can lead to an insufficient oxygen supply, potentially reducing the photodynamic efficacy. In response to this issue, we have devised a pH-responsive amphiphilic triblock fluorinated polymer (PDP) using copper-mediated RDRP. This polymer, composed of poly(ethylene glycol) methyl ether acrylate, 2-(diethylamino)ethyl methacrylate, and (perfluorooctyl)ethyl acrylate, self-assembles in an aqueous environment. Oxygen, chlorine e6 (Ce6), and doxorubicin (DOX) can be codelivered efficiently by PDP. The incorporation of perfluorocarbon into the formulation enhances the oxygen-carrying capacity of PDP, consequently extending the lifetime of 1O2. This increased lifetime, in turn, amplifies the PDT effect and escalates the cellular cytotoxicity. Compared with PDT alone, PDP@Ce6-DOX-O2 NPs demonstrated significant inhibition of tumor growth. This study proposes a novel strategy for enhancing the efficacy of PDT.

Poly(ethylene glycol) Methyl Ether Acrylate-Grafted Chitosan-Based Micro- and Nanoparticles as a Drug Delivery System for Antibiotics.

Nanotechnology is the science of creating materials at the nanoscale by using various devices, structures, and systems that are often inspired by nature. Micro- and nanoparticles (MPs, NPs) are examples of such materials that have unique properties and can be used as carriers for delivering drugs for different biomedical applications. Chitosan (CS) is a natural polysaccharide that has been widely studied, but it has a problem with low water solubility at neutral or basic pH, which limits its processability. The goal of this work was to use a chemically modified CS with poly(ethylene glycol) methyl ether acrylate (PEGA) to prepare CS micronic and submicronic particles (MPs/NPs) that can deliver different types of antibiotics, respectively, levofloxacin (LEV) and Ciprofloxacin (CIP). The particle preparation procedure employed a double crosslinking method, ionic followed by a covalent, in a water/oil emulsion. The studied process parameters were the precursor concentration, stirring speeds, and amount of ionic crosslinking agent. MPs/NPs were characterized by FT-IR, SEM, light scattering granulometry, and Zeta potential. MPs/NPs were also tested for their water uptake capacity in acidic and neutral pH conditions, and the results showed that they had a pH-dependent behavior. The MPs/NPs were then used to encapsulate two separate drugs, LEV and CIP, and they showed excellent drug loading and release capacity. The MPs/NPs were also found to be safe for cells and blood, which demonstrated their potential as suitable drug delivery systems for biomedical applications.

Effects of stirring rate on morphology of aqueous RAFT emulsion PISA-derived block copolymer nanoparticles

The influence of stirring rate on nanoparticle morphology in aqueous RAFT emulsion PISA has been investigated.

Preparation and characterization of magnetic microgels with linear thermosensitivity over a wide temperature range

Abstract Hybrid nanogels that are both thermosensitive and superparamagnetic, and have good biocompatibility are expected to have applications in the biomedical field. In this article, a linearly thermosensitive magnetic microgel was prepared by a radical copolymerization reaction in aqueous dispersion. In this reaction, poly(ethylene glycol) diacrylate was used as a crosslinker, polyvinylpyrrolidone was used as a stabilizer, and 2-methoxyethyl acrylate, poly(ethylene glycol)methyl ether acrylate, and 2-(methacryloyloxy)ethyl acetoacetate were used as copolymer monomers. The thermosensitive magnetic microgel displays a linear volume phase transition in water upon heating over a wide range of temperatures. Transmission electron microscopy, scanning electron microscopy, and dynamic light scattering were used to characterize the morphology and dimensions of the thermosensitive magnetic microgel. This material is expected to be used in magnetically targeted drug delivery systems that require linear drug release.

Ultra-thin and high-voltage-stable Bi-phasic solid polymer electrolytes for high-energy-density Li metal batteries

Solid-state electrolytes (SSEs) are essential materials in all-solid-state lithium-metal batteries. However, a comprehensive SSE possessing high ionic conductivity, broad electrochemical window, and high thermal stability remains elusive. In this work, a novel bi-phase SSE featuring a shape memory effect is developed by in-situ thermal cross-linking of 2-ethyl cyanoacrylate (CA), polyethylene glycol methyl ether acrylate (PEGMEA), succinonitrile (SN), and fluoroethylene carbonate (FEC) additives. Due to the phase separation phenomenon and interfacial Li-ion conduction, the bi-phase SSE exhibits a room-temperature ionic conductivity of 1.9 mS cm−1. Meanwhile, the bi-phase SSE exhibits a high oxidation potential of 4.9 V (vs Li/Li+), and a lithium-ion transference number (tLi+) of 0.56. Coupling with LiNi0.8Co0.1Mn0.1O2 (NCM 811) cathode and 11 µm bi-phase SSE, solid-state lithium metal batteries (SSLMBs) demonstrate long-term cycling stability (capacity retention > 92% after 250 cycles), excellent rate performance (126 mA h g−1 at 2 C, and high-voltage stability (208 mA h g−1 at 4.5 V). This investigation demonstrates the potential of bi-phase SSEs as a promising material for the development of high-performance SSLMBs.

Preparation of PFPE-Based Polymeric Nanoparticles via Polymerization-Induced Self-Assembly as Contrast Agents for 19F MRI.

Fluorine-19 magnetic resonance imaging (19F MRI) probes have received considerable research interest as imaging contrast agents (CAs), but they remain neglected and underutilized due to the limited fluorine content or poor performance of fluorinated tracers. Here, we present polymeric nanoparticles (NPs) as 19F MRI CAs with a simple synthesis method and promising imaging performance. First, hydrophilic random copolymers were synthesized from oligo(ethylene glycol) methyl ether acrylate and perfluoropolyether methacrylate by reversible addition-fragmentation chain transfer (RAFT) polymerization. The optimal fluorine content, polymer concentration, and cytotoxicity as 19F MRI CAs were investigated in detail. Then, the optimal copolymer was selected as the macromolecular chain transfer agent, and the chain extension was performed with 2-(perfluorooctyl ethyl methacrylate). Subsequently, the NPs with different morphologies, such as ellipsoidal, spherical nanoparticles and vesicles, were prepared in situ by the RAFT-mediated polymerization-induced self-assembly method. In addition, the 19F MRI signal and cytotoxicity studies further confirmed that these polymeric NPs are nontoxic and have great potential as promising 19F MRI CAs for biological applications.

Polymer film synthesis from an aqueous latex of polymerization-induced self-assembly (PISA) derived nanofibers

Polymerization-induced self-assembly (PISA) derived spheres and worms (fibers) comprising poly(n-butyl acrylate) as core-forming block (Tg ≈ −49 °C) were synthesized using a poly(acrylic acid-stat-poly(ethylene glycol) methyl ether acrylate) macroRAFT agent. The nanoparticle morphology varied depending on the pH of the system, i.e. spheres at natural pH (≈ 2.5) and worms at pH 5. The core-sections of the particles (both spheres and worms) were crosslinked using ethylene glycol diacrylate. Films were prepared from the synthesized aqueous latexes via simple drop casting in the absence of volatile organic compounds. The influence of the original nanoparticle morphology on the mechanical properties of the films was subsequently explored – “worm film” displayed 1670 % higher tensile strength and 1290 % higher strain at break compared to “sphere film”. These results demonstrate that film properties can be significantly influenced by the original nanoparticle morphology, despite the nanoparticles comprising very similar polymer chains in terms of composition and molecular weight distribution.

Active Learning as a Tool for Optimizing “Plug‐n‐Play” Electrochemical Atom Transfer Radical Polymerization

AbstractA recently reported “plug‐n‐play” approach to simplified electrochemical atom transfer radical polymerization (seATRP) is investigated using machine learning. It is shown that Bayesian optimization via an active learning (AL) algorithm accelerates optimization of the polymerization of oligo(ethylene glycol methyl ether acrylate)480 (OEGA480) in water. Molecular weight distribution (Mw/Mn; dispersity; Ɖm) is the output selected for optimization targeting poly(oligo[ethylene glycol methyl ether acrylate]) (POEGA480) with low dispersity (Ɖm < 1.30). Input variables included applied potential (Eapp), [M] and [M]/[I], which led to a potential space of 275 possible reaction conditions. From a training data set of seven reactions, selected to yield uncontrolled POEGA480 with higher dispersities (Ɖm > 1.5), ten iteration loops are performed. During each iteration the algorithm suggests the next reaction conditions. The reactions are then performed and the conversion, number average molecular weight (Mn) and Ɖm values are recorded and the Ɖm values fed back into the algorithm. Overall, 80% of the experiments yield POEGA with Ɖm < 1.30. Conversely, only 30% of experiments performed using reaction conditions selected at random from the possible reaction space yield POEGA with Ɖm < 1.30. This study suggests that adopting AL methods can improve the efficiency of optimizing a given seATRP reaction.

Nitroxide-containing amphiphilic polymers prepared by simplified electrochemically mediated ATRP as candidates for therapeutic antioxidants

Nitroxide-containing amphiphilic polymers for therapeutic use were prepared in two-step procedure. Firstly, amphiphilic copolymers composed of hydrophobic poly(n-butyl acrylate) (PnBA) and hydrophilic poly[oligo(ethylene glycol) methyl ether acrylate] (POEGA) or poly(2-hydroxyethyl acrylate) (PHEA) were synthesized by simplified electrochemically mediated atom transfer radical polymerization (seATRP). Due to the precisely-controlled structure of each polymer block proved by narrow dispersity (Mw/Mn < 1.19), chain-end halide functionality of macromolecules was preserved. Therefore, it was possible to efficiently convert the halide atom at the end of the chain to stable radicals via the amination of the polymer with 4-amino-2,2,6,6-tetrametylopiperydynyloksyl (4-amino-TEMPO, 4-AT). The prepared polymers are able to self-assemble in an aqueous solution into micelles with a hydrodynamic diameter of approximately 31 nm measured by dynamic light scattering (DLS) analysis. The susceptibility of the prepared micelles for biomedical applications was studied by evaluation of the effect on erythrocytes and fibroblasts and their antioxidant properties by testing of inhibition of oxidation reactions – oxidation of dihydrorhodamine 123 (DHR 123), induced by biologically relevant oxidants. The antioxidant effects of polymeric micelles were compared with those of free 4-AT. Prepared TEMPO-containing micelles exhibited biocompatibility in interaction with human erythrocytes and fibroblasts and exerted antioxidant effects. Therefore, the micelles are potentially good candidates for in vivo applications.

Improved Solid Electrolyte Conductivity via Macromolecular Self-Assembly: From Linear to Star Comb-like P(S-co-BzMA)-b-POEGA Block Copolymers.

Star block copolymer electrolytes with a lithium-ion conducting phase are investigated in the present work to assess the influence of this complex architecture compared to that of the linear one, on both, bulk morphology and ionic conductivity. For that purpose, the controlled synthesis of a series of poly(styrene-co-benzyl methacrylate)-b-poly[oligo(ethylene glycol) methyl ether acrylate] [P(S-co-BzMA)-b-POEGA] block copolymers (BCPs) by reversible addition-fragmentation transfer polymerization was performed from either a monofunctional or a tetrafunctional chain transfer agent containing trithiocarbonate groups. We emphasized how a small amount of styrene (6 mol %) drastically improved the control of the RAFT polymerization of benzyl methacrylate mediated by the tetrafunctional chain transfer agent. Transmission electron microscopy and small-angle X-ray scattering demonstrated a clear segregation of the BCPs in the presence of lithium salt. Interestingly, the star BCPs gave rise to highly ordered lamellar structures as compared to that of the linear analogues. Consequently, the reduced lamellae tortuosity of self-assembled star BCPs improved the lithium conductivity by more than 8 times at 30 °C for ∼30 wt % of the POEGA conductive phase.

Characterizing the Molecular Architecture of Hydrogels and Crosslinked Polymer Networks beyond Flory-Rehner. II: Experiments.

We previously [Borges, F. T. P. Biomacromolecules 2020, 21(12), 5104-5118] introduced a novel methodology for the characterization of the dimensions and architecture of hydrogel networks that provides more detailed information than the classical Flory-Rehner theory [Canal, T.; Peppas, N. A. J. Biomed. Mater. Res. 1989, 23, 1183-1193]. In this article, we illustrate our methodology by applying it to the phototerpolymerization of N-vinyl-2-pyrrolidone (NVP), ethylene glycol methyl ether acrylate (EGA), and poly(ethylene glycol) diacrylate (PEGDA). The experimental design includes 120 formulations using different fractions of the three monomers. Experimental measurements determined the mass swelling ratio and were coupled with theory to compute the internal dimensions of the network. Results demonstrate how the use of a macromeric crosslinker leads to unique network architectures not predicted by classical F-R theory, e.g., the figure shows that the mass between crosslinks predicted by F-R is actually distributed between branches and the backbone. The methodology presented offers a path toward optimizing/customizing hydrogel properties to suit the size and shape of the specific therapeutic targeted for drug delivery.