Poly(ethylene Glycol) Methyl Ether Acrylate Research Articles

Li6.28La3Zr2Al0.24O12-reinforced Single-ion Conducting Composite Polymer Electrolyte for Room-Temperature Li-Metal Batteries

Composite polymer electrolytes composed of inorganic fillers and organic polymers are promising electrolyte candidates for Li metal batteries, with benefits of improved safety and suppressed lithium dendrite growth. However, a severe concentration polarization effect often occurs when using conventional dual-ion electrolytes, and the increase in internal impedance during cycling results in decreased lifespan of the battery. To address this challenge, a plasticized single-ion conducting composite polymer electrolyte (SICE) was designed and fabricated by polymerizing the monomers of lithium (4-styrenesulfonyl) (trifluoromethanesulfonyl) imide (LiSTFSI) and poly(ethylene glycol) methyl ether acrylate (PEGMEA), crosslinker poly(ethylene glycol) diacrylate (PEGDA), silane-modified Li6.28La3Al0.24Zr2O12 nanofibers (s@LLAZO NFs), along with a PEG-based plasticizer tetraethylene glycol dimethyl ether (TEGDME), by heat-initiation. The anions were restrained and delocalized so that only Li cation migration occurred during the charging/discharging process, leading to a superior lithium-ion transference number. The s@LLAZO NFs enabled direct monomer grafting with the polymer matrix, resulting in controlled formation of an organic-inorganic network with increased filler content and improved filler distribution in the SICE system. The SICE membrane exhibited high ionic conductivity at room temperature, reduced activation energy and excellent oxidation stability. Most importantly, the all-solid-state Li-metal batteries assembled with the fabricated SICE demonstrated stable long-term cycling performance and remarkable rate capability at room temperature.

CO2-Philic Nanocomposite Polymer Matrix Incorporated with MXene Nanosheets for Ultraefficient CO2 Capture.

The incorporation of two-dimensional (2D) functional nanosheets in polymeric membranes is a promising material strategy to overcome their inherent performance trade-off behavior. Herein, we report a novel nanocomposite membrane design by incorporating MXene, a 2D sheet-like nanoarchitecture known for its advantageous lamellar morphology and surface functionalities, into a cross-linked polyether block amide (Pebax)/poly(ethylene glycol) methyl ether acrylate (PEGMEA) blend matrix, which delivered exceptional CO2/N2 and CO2/H2 separation performances that are critical to industrial CO2 capture applications. The finely dispersed Ti3C2Tx nanosheets in the blend polymer matrix led to an expansion of the free volume within the resultant mixed matrix membrane (MMM), giving rise to a substantially enhanced CO2 permeability of up to 1264.6 barrer, which is 102% higher than that of the pristine polymer. Moreover, these MXene-incorporated MMMs exhibited preferential sorption for CO2 over light gases, which contributed to an exceptional CO2/N2 and CO2/H2 selectivity (64.3 and 19.2, respectively) even at a small loading of only 1 wt %, allowing the overall performance to not only surpass the latest upper bounds but also exceed many previously reported high-performance nanosheet-based nanocomposite membranes. Long-term performance tests have also demonstrated the good stability of these membranes. This composite membrane design strategy reveals the remarkable potential of combining a blend copolymer matrix with ultrathin MXene nanosheets to achieve superior gas separation performance for environmentally important gas separations.

Fabrication and evaluation of novel amphiphilic star block copolymers for increasing free water content in lignite to make coal water slurries

In order to reduce the apparent viscosity of lignite coal water slurries (CWSs) and improve its static stability, a series of three-arm amphiphilic block copolymers have been prepared through RAFT polymerization by using poly(ethylene glycol) methyl ether acrylate (PEGMA) and sodium 4-vinylbenzenesulfonate (SSNa) as hydrophilic monomers and styrene (St) as hydrophobic monomer. The chemical structure of the copolymers has been investigated, and the impact of relative molecular weight, hydrophilic/hydrophobic ratio, and ionic group content on the pulping performance of three-arm amphiphilic block copolymers has been examined. The lignite coal water slurries (CWSs) prepared from the block copolymer tri-P(St50-s-SSNa50)10K-b-PPEGMA10K exhibit a remarkably low apparent viscosity of 395 mPa·s and excellent static stability when the coal content is at 55 wt% and dispersant content is at 0.5 wt%. Moreover, these CWSs can achieve a maximum pulping concentration of up to 59 wt%. Additionally, the thermogravimetric test reveals insights into the water occurrence in CWSs, indicating that higher levels of free water content correspond to lower apparent viscosities. Suitable hydrophobicity facilitates the removal of internal water from lignite by dispersants, disrupting its flocculation structure and promoting CWSs formation. Meanwhile, the presence of ionic groups enhances the static stability of the resulting CWSs. Furthermore, the adsorption behavior of the three-arm amphiphilic block copolymer dispersant in lignite has been analyzed through XPS testing to elucidate its dispersion mechanism. The use of three-arm amphiphilic block copolymers in preparing lignite CWSs results in lower apparent viscosity and improved static stability, attributed to the amphiphilic and steric hindrance effects of dispersants. This not only expands the application range of lignite CWSs but also highlights the significant potential of this type of dispersant.

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.

Eutectic-Based Polymer Electrolyte with the Enhanced Lithium Salt Dissociation for High-Performance Lithium Metal Batteries.

The deployment of lithium metal anode in solid-state batteries with polymer electrolytes has been recognized as a promising approach to achieving high-energy-density technologies. However, the practical application of the polymer electrolytes is currently constrained by various challenges, including low ionic conductivity, inadequate electrochemical window, and poor interface stability. To address these issues, a novel eutectic-based polymer electrolyte consisting of succinonitrile (SN) and poly (ethylene glycol) methyl ether acrylate (PEGMEA) is developed. The research results demonstrate that the interactions between SN and PEGMEA promote the dissociation of the lithium difluoro(oxalato) borate (LiDFOB) salt and increase the concentration of free Li+ . The well-designed eutectic-based PAN1.2 -SPE (PEGMEA: SN=1: 1.2 mass ratio) exhibits high ionic conductivity of 1.30 mS cm-1 at 30 °C and superior interface stability with Li anode. The Li/Li symmetric cell based on PAN1.2 -SPE enables long-term plating/stripping at 0.3 and 0.5 mA cm-2 , and the Li/LiFePO4 cell achieves superior long-term cycling stability (capacity retention of 80.3 % after 1500 cycles). Moreover, Li/LiFePO4 and Li/LiNi0.6 Co0.2 Mn0.2 O2 pouch cells employing PAN1.2 -SPE demonstrate excellent cycling and safety characteristics. This study presents a new pathway for designing high-performance polymer electrolytes and promotes the practical application of high-stable lithium metal batteries.

Eutectic‐Based Polymer Electrolyte with the Enhanced Lithium Salt Dissociation for High‐Performance Lithium Metal Batteries

AbstractThe deployment of lithium metal anode in solid‐state batteries with polymer electrolytes has been recognized as a promising approach to achieving high‐energy‐density technologies. However, the practical application of the polymer electrolytes is currently constrained by various challenges, including low ionic conductivity, inadequate electrochemical window, and poor interface stability. To address these issues, a novel eutectic‐based polymer electrolyte consisting of succinonitrile (SN) and poly (ethylene glycol) methyl ether acrylate (PEGMEA) is developed. The research results demonstrate that the interactions between SN and PEGMEA promote the dissociation of the lithium difluoro(oxalato) borate (LiDFOB) salt and increase the concentration of free Li+. The well‐designed eutectic‐based PAN1.2‐SPE (PEGMEA: SN=1: 1.2 mass ratio) exhibits high ionic conductivity of 1.30 mS cm−1 at 30 °C and superior interface stability with Li anode. The Li/Li symmetric cell based on PAN1.2‐SPE enables long‐term plating/stripping at 0.3 and 0.5 mA cm−2, and the Li/LiFePO4 cell achieves superior long‐term cycling stability (capacity retention of 80.3 % after 1500 cycles). Moreover, Li/LiFePO4 and Li/LiNi0.6Co0.2Mn0.2O2 pouch cells employing PAN1.2‐SPE demonstrate excellent cycling and safety characteristics. This study presents a new pathway for designing high‐performance polymer electrolytes and promotes the practical application of high‐stable lithium metal batteries.

Blood compatible, fog-, frost- and bacterial-resistant dopamine-enabled zwitterionic glass interfaces

BackgroundHydration is at the core of the mechanisms rationalizing the ability of hydrophilic interfaces to resist fogging, frosting and biofouling, and to be hemocompatible. Although essential, very few biomedical interfaces and devices possess this set of properties. MethodsThis study sheds light on this combination of properties imparted to glass by a dopamine-enabled grafting of poly(sulfobetaine methacrylate) moieties. Water contact angle (WCA), fogging, frost resistance antifouling and blood compatibility tests were then conducted. Significant FindingsThe very low WCA measured on the glass surface (8.4°) permitted to inhibit condensation and maintain optical transparency, whereas other hydrophilic graftings prepared using hydroxyethylmethacyrlate (HEMA) or poly(ethylene glycol) methyl ether acrylate (PEGMA) lost 15% of their optical transparency. The strong hydration layer provided by the zwitterionic grafting almost entirely inhibited frost formation. While the virgin glass suffered from severe biofouling by various types of cells found in the medical field including Pseudomonas aeruginosa and whole blood, the grafted glass materials resisted biofouling efficiently (90% and 99% decrease using bacteria and whole blood, respectively). Hemocompatibility was supported by negligible haemolyis activity, and activated partial thromboplastin time (APTT, 32.1 s) and prothrombin time (PT, 10.4 s) comparable to those measured with whole blood. Stability was also proven by carrying out antifouling tests after 1 month-immersion in an ultrasonic bath. Thus, these zwitterionic glass materials have potential for application in the biomedical field.

Enhancing Performance of LiFePO4 Battery by Using a Novel Gel Composite Polymer Electrolyte

Composite polymer electrolyte (CPE) is expected to have great prospects in solid-state batteries. However, their application is impeded due to the poor interfacial compatibility between CPE and electrodes that result in sluggish ionic transformation, especially at low temperatures. Here, on the basis of Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) polymer electrolyte, gel composite polymer electrolyte (GCPE) with fast Li+ transport channel is prepared by in-situ polymerization with poly (ethylene glycol) methyl ether acrylate (PEGMEA) monomer and FEC as additive. Compared with CPE, GCPE increases the ionic conductivity by 10 times. It also achieves more uniform lithium precipitation and significantly inhibits the growth of lithium dendrites. The LFP/GCPE/Li battery has a capacity retention of over 99% at both room temperature and 0 °C after 100 cycles. In addition, the coulombic efficiency is above 99% during cycling. Our work provides a new technology to prepare GCPE with high ionic conductivity at both room temperature and low temperatures that has great potential in the application of solid-state lithium batteries.

From monomer to micelle: a facile approach to the multi-step synthesis of block copolymers via inline purification.

A one-pass continuous flow strategy to form block copolymer nanoaggregates directly from monomers is presented. A key development towards such a sophisticated continuous flow setup is a significant improvement in continuous flow dialysis. Often impurities or solvent residues from polymerizations must be removed before block extensions or nanoaggregate formation can be carried out, typically disrupting the workflow. Hence, inline purification systems are required for fully continuous operation and eventual high throughput operation. An inline dialysis purification system is developed and exemplified for amphiphilic block copolymer synthesis from thermal and photoiniferter reversible addition fragmentation chain transfer (RAFT) polymerization. The inline dialysis system is found to be significantly faster than conventional batch dialysis and the kinetics are found to be very predictable with a diffusion velocity coefficient of 4.1 × 10-4 s-1. This is at least 4-5 times faster than conventional dialysis. Moreover, the newly developed setup uses only 57 mL of solvent for purification per gram of polymer, again reducing the required amount by almost an order of magnitude compared to conventional methods. Methyl methacrylate (MMA) or butyl acrylate (BA) was polymerized in a traditional flow reactor as the first block via RAFT polymerization, followed by a 'dialysis loop', which contains a custom-built inline dialysis device. Clearance of residual monomers is monitored via in-line NMR. The purified reaction mixture can then be chain extended in a second reactor stage to obtain block copolymers using poly(ethylene glycol) methyl ether acrylate (PEGMEA) as the second monomer. In the last step, nano-objects are created, again from flow processes. The process is highly tuneable, showing for the chosen model system a variation in nanoaggregate size from 34 nm to 188 nm.

A Quasi‐Solid Electrolyte by In Situ Polymerization of Selective Solvent for Lithium‐Metal Batteries

AbstractLithium (Li) metal is a competitive anode material for rechargeable high energy density batteries due to its high specific capacity and low reduction potential. However, great challenges remain in addressing uncontrollable Li dendrite growth and unstable interface. Herein, we report a quasi‐solid electrolyte enabled by in situ polymerization of polyethylene glycol methyl ether acrylate. Meanwhile, a LiF‐enriched solid electrolyte interphase (SEI) is built on Li‐metal surface by function of the fluoroethylene carbonate additive. The SEI with a good mechanical stability prompts the dense and uniform Li deposition behavior. The in situ polymerized gel polymer electrolyte exhibits an ionic conductivity of 1.71×10−4 S cm−1 at 30 °C, and a considerable oxidative stability up to 4.5 V (vs. Li/Li+). The Li||Li symmetric cells delivers a long‐term cycle life over 1400 h and a low voltage hysteresis at 0.5 mA cm−2, 1 mAh cm−2. To be paired with a LiFePO4 positive electrode, the cell shows a high discharge capacity of 135.6 mAh g−1 and capacity retention of 92.7 % after 300 cycles. This work provides a reference for the practical development of quasi‐solid electrolyte for lithium‐metal battery.

Reversible lithium deposition/dissolution reaction with low polarization through a cross-linked polymer: Geometrical structure effects of the polymer protective layer on lithium metal anodes

A lithium metal anode was coated with a cross-linked PEO-based polymer composed of poly(ethylene glycol) diacrylate (PEGDA) as a cross-linker and poly(ethylene glycol) methyl ether acrylate (PEGMA) as a base polymer to suppress electrolyte decomposition and lithium dendrite formation, thereby improving its electrochemical performance. The ca. 10 μm thick polymer membranes with flat and pore-free surface were successfully fabricated on the lithium metal electrode. Physicochemical characteristics of the synthesized polymer membrane such as elastic modulus, electrolyte uptake and mesh size indicate that polymer structure is changed from a linear structure to a bridged network one and increased in its crosslinking density by mixing PEGDA. The PEGDA increased the connectivity of the nanosized cross-linked domains, which led to improvement of the lithium ion transport number in membrane, and polarization and reversibility of deposition/dissolution reaction of lithium. Additionally, no dendrite formation was observed during lithium deposition/dissolution reaction through the bridged network structured polymer membrane. The structure of the PEO-based coating polymer is one of the important factors in the stabilization of the deposition/dissolution reactions of lithium metal anodes, and a bridged-network structure with preferential ion transport capability is more effective to improve these reactions than a straight-chain structure.

GeFSIX‐1‐Cu based semi‐interpenetrating network mixed matrix membranes for efficient CO2 separation

AbstractIn order to increase CO2 separation efficiency, semi‐interpenetrating network mixed matrix membranes (SIPN‐MMMs) were loaded with GeFSIX‐1‐Cu (Cu(4,4′‐bipyridine)2(GeF6)) and poly ethylene glycol dimethyl ether (PEGDME). Two long‐chain polymers poly ethylene glycol diacrylate (PEGDA) and poly ethylene glycol methyl ether acrylate (PEGMEA) jointly constituted a crosslinked PEO backbone, and CO2‐philic short‐chain polymer PEGDME and anion‐pillared hybrid porous materials GeFSIX‐1‐Cu were embedded into the backbone to introduce strong CO2 adsorption sites and provide extra pore channels. Increasing GeFSIX‐1‐Cu loading in SIPN‐MMMs initially improved CO2 permeability and CO2/N2, CO2/CH4, and CO2/H2 selectivity, because the porous structure of GeFSIX‐1‐Cu provides additional pore channels for gas transport. In addition, the strong binding affinity between GeF62− and CO2 leads to improved membrane selectivity. When GeFSIX‐1‐Cu loading increased above 3 wt%, both CO2 permeability and CO2/N2, CO2/CH4, and CO2/H2 selectivity decreased, due to agglomeration of excess GeFSIX‐1‐Cu loading in SIPN‐MMMs. The highest CO2 permeability of 786 Barrer and CO2/N2 ideal selectivity of 43 (at GeFSIX‐1‐Cu loading of 3 wt%) were 36% and 38% higher than those of pure SIPN membrane, respectively, resolving the trade‐off between permeability and selectivity, and surpassing the Robeson upper bound (2008).

Novel porphyrin-containing hydrogels obtained by frontal polymerization: Synthesis, characterization and optical properties

Frontal polymerization was successfully used to prepare two series of copolymers from a tetraphenylporphyrin-containing monomer (TPP-TEG-MA) and poly(ethylene glycol) methyl ether acrylate (PEGMA) or di(ethylene glycol) methyl ether methacrylate (DEGMA). Tricaprylmethylammonium (Aliquat) persulfate (APSO) was used as radical initiator to obtain highly fluorescent hydrogels with different chromophore contents. The obtained hydrogels, PEGTPP and DEGTPP series, were characterized by FT-IR spectroscopy, and the successful incorporation of TPP-TEG-MA monomer into the polymer backbone was observed. Their thermal properties were determined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The swelling behavior of the obtained hydrogels was measured at 25 °C and pH = 7. The swelling ratio increased until equilibrium was reached after 24 h. Furthermore, the pH and temperature responses of the obtained hydrogels were measured. The optical properties of these materials were studied by absorption and fluorescence spectroscopies. They exhibited an absorption band at 418 nm (Soret band) and an emission band at 653 nm, which are typical of the porphyrin moiety.

Tailor-made microstructures lead to high-performance robust PEO membrane for CO2 capture via green fabrication technique

Emerging excessive greenhouse gas emissions pose great threats to the ecosystem, which thus requires efficient CO2 capture to mitigate the disastrous issue. In this report, large molecular size bisphenol A ethoxylate diacrylate (BPA) was employed to crosslink poly (ethylene glycol) methyl ether acrylate (PEGMEA) via the green and rapid UV polymerization strategy. The microstructure of such-prepared membrane could be conveniently tailored by tuning the ratio of the two prepolymers, aiming at obtaining the optimized microstructures with suitable mesh size and PEO sol content, which was approved by a novel low-field nuclear magnetic resonance technique. The optimum membrane overcomes the trade-off challenge: dense microstructures lower the gas permeability while loose microstructures lower high-pressure-resistance capacity, realizing a high CO2 permeability of 1711 Barrer and 100-h long-term running stability under 15 atm. The proposed membrane fabrication approach, hence, opens a novel gate for developing high-performance robust membranes for CO2 capture.

Thin-film composite membranes based on hyperbranched poly(ethylene oxide) for CO2/N2 separation

Cross-linked amorphous poly(ethylene oxide) (XLPEO) is one of the leading membrane materials for post-combustion CO 2 capture. For example, XLPEO prepared from poly(ethylene glycol) methyl ether acrylate (PEGMEA) exhibited CO 2 permeability of 570 Barrer and CO 2 /N 2 selectivity of 41 at 35 °C. However, these XLPEOs cannot be dissolved in coating solutions, making it impossible to be fabricated into thin-film composite (TFC) membranes using state-of-the-art manufacturing processes. In this study, we synthesized high molecular weight yet soluble HPEO via atom transfer radical polymerization (ATRP). These polymers were thoroughly characterized and compared with XLPEO, including thermal transitions, free volumes, and pure-gas sorption and permeation properties. A polymer with the best combination of CO 2 permeability (540 Barrer) and CO 2 /N 2 selectivity (43) was fabricated into defect-free TFC membranes with a thickness as thin as 506 ± 44 nm. When challenged with simulated flue gas containing water vapor at 35 °C for over 100 h, the membrane shows stable CO 2 permeance of 850 GPU and CO 2 /N 2 selectivity of 37, comparable to the leading commercial membranes for carbon capture. • Hyperbranched PEO (HPEO) was synthesized by atom transfer radical polymerization. • HPEO 2 shows gas transport properties similar to those prepared by photopolymerization. • HPEO 2 can be fabricated into thin film composite membranes of 500 nm. • HPEO 2 membranes show one of the best CO 2 /N 2 separation properties reported. • Membranes demonstrate robust carbon capture performance with model flue gas.

Scale-up processing of a safe quasi-solid-state lithium battery by cathode-supported solid electrolyte coating

A solid-state lithium metal battery has been considered as a promising next-generation energy storage system for its high safety. Great challenges remain for the scale-up fabrication of solid-state Li batteries with the current manufacturing facility used for liquid Li-ion batteries. In this work, a scale-up route is employed to fabricate quasi-solid-state Li batteries by cathode-supported coating of a solid electrolyte combined with in-situ polymerization for interfacial modification. A Li1.3Al0.3Ti1.7(PO4)3 (LATP) layer with a polyvinylidene fluoride (PVDF) binder is coated on the LiCoO2 cathode as the solid electrolyte. A iquid electrolyte containing a poly(ethylene glycol) methyl ether acrylate (PEGMEA) monomer is injected during the battery fabrication process followed by in-situ polymerization. The in-situ formed gel electrolyte acts as a soft interface to enhance the contact between the electrode and the solid electrolyte. A coin-type quasi-solid-state Li||LiCoO2 battery delivers a high capacity of 122 mAh g−1 and retains 81% of its initial capacity after 100 cycles at 0.5 C and 60 °C. A pouch-type Li||LiCoO2 battery is also fabricated using a commercial LiCoO2 electrode and shows a satisfactory safety performance and stable cycling at 0.5 C.

Fabrication of polymer electrolyte via lithium salt-induced surface-initiated radical polymerization for lithium metal batteries

The fabrication of flexible polymer electrolytes (PEs) which possess simultaneously high thermal stability, robust mechanical strength, and high ionic conductivity is very challenging for lithium (Li) batteries. Herein, cellulose-based PE is fabricated via a Li salt-induced surface-initiated radical polymerization of polyethylene glycol methyl ether acrylate (PEGA). The polymerization of PEGA is catalyzed by various Li salts, such as Li perchlorate (LiClO4), bis(trifluoromethane)sulfonimide Li (LiTFSI), Li difluoro(oxalato)borate (LiDFOB), and LiClO4/LiDFOB, which also serve as charge transfer carriers in PEs. The Li salt can be used as the catalyst to promote the cleavage of C–Br bond on the surface of Br-modified cellulose, and then initiate the polymerization of PEGA. The PE obtained from the dual salt (LiClO4/LiDFOB)-induced radical polymerization system exhibits high ionic conductivity of 3.5 × 10−5 S cm−1 at 30 °C, good thermal stability (up to 240 °C), and wide electrochemical stability window (5.0 V vs. Li/Li+). Moreover, Li/PE/Li symmetric cells show good interfacial stability between PE and Li foil and the assembled Li/PE/LiFePO4 cells possess 150 mA h g−1 at 0.1C. Li salt-induced surface-initiated polymerization provides a simple and efficient method for fabricating PE for high-performance Li metal batteries (LMBs).

Controlling the Chain Folding for the Synthesis of Single-Chain Polymer Nanoparticles Using Thermoresponsive Polymers

Synthetic polymer single-chain nanoparticles (SCNPs) are an emerging new class of nanomaterials that possess similar folded structures as natural proteins. However, most SCNPs reported so far are p...

Mechanoelectrical Transduction of Polymer Electrolyte Membranes: Effect of Branched Networks.

The role of side-chain branching in flexoelectric properties of a flexible, ionic solid polymer electrolyte membrane (PEM) has been investigated subjected to mechanical bending. These PEMs were synthesized via photopolymerization of the bifunctional poly(ethylene glycol) diacrylate (PEGDA) network attached with monofunctional poly(ethylene glycol) methyl ether acrylate (PEGMEA) branches in their ternary mixtures with lithium bis(tri-fluoromethane sulfonyl) imide (LiTFSI) salt. Both the PEGDA polymer precursor and PEGDMA side branches are capable of ionizing the lithium salt, but the dissociated lithium cations can also form the complexation with ether oxygen of PEGDA. With increasing PEGMEA content, not only the glass transition temperature is lowered, but also the ionic conductivity increases with temperature, which may be attributed to plasticization by dangling PEGMEA side chains. The flexoelectric responses of PEMs were investigated under various intermittent and oscillatory cantilever bending modes as a function of PEM composition and frequency. Last but not the least, the mechanoelectrical energy conversion was evaluated for various PEGDA/PEGMEA compositions and discussed its potential applications in energy harvesting from natural resources such as wind and wave motions.

Brush-shaped RAFT polymer micelles as nanocarriers for a ruthenium (II) complex photodynamic anticancer drug

Amphiphilic polymers containing brush-shaped poly(polyethylene glycol methyl ether acrylate) (PEGA) as a hydrophilic segment may form a stable hydrophilic shell for a polymeric micelle due to a strong interaction among the brush shaped molecules. In this paper, polymeric micelles with brush-shaped poly(PEGA) as hydrophilic shell were designed and formulated as nanocarriers for a new ruthenium (II) complex anticancer drug to address its poor water solubility. Well defined brush-shaped poly(PEGA)-containing amphiphilic block polymers were synthesised by reversible addition-fragmentation chain transfer (RAFT) polymerisation. The as-prepared amphiphilic polymers formed stable polymeric micelle nanocarriers for the hydrophobic ruthenium (II) complex, resulting in greatly increased solubility of the drug by inhibiting its aggregation in aqueous environment. Cytotoxicity studies demonstrated that the use of polymeric micelle nanocarriers increased the drug’s toxicity to human liver cancer cells (SK-HEP-1) by 3 fold under dark and 12 fold under light conditions. However, both bare drug and encapsulated drug showed no toxicity to the normal cells, demonstrating the drug’s potential targeting capacity to cancer cells.