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To employ Li-based batteries to their full potential in a wide range of energy-storage applications, their capacity and performance stability must be improved. Si is a viable anode material for Li-based batteries in electric vehicles due to its high theoretical capacity and good economic feasibility. However, it suffers from physical and chemical degradation, leading to unstable electrochemical performance and preventing its incorporation in new Li-based battery systems. Herein, we applied a poly(vinyl alcohol)-PO4 protective coating for Si-graphite anodes and confirmed an improvement in the electrochemical performance. The experimental results revealed that the polymer acts as a binder to alleviate the pulverization of the electrode. Furthermore, the oxide coating reduces the loss of Li2O, which has high ionic conductivity, during operation, resulting in the formation of a stable solid electrolyte interphase. Our findings suggest that a stable and ion-conducting anode/interphase can be developed by apply...

The use of forward osmosis (FO) process for seawater desalination has attracted tremendous interest in recent years. Besides the manufacture of suitable membranes, the major technical challenge in the efficient deployment of the FO technology lies in the development of a suitable "draw solute". Owing to its inherent advantages, poly(aspartic acid) has arisen to be an attractive candidate for this purpose. However, an investigation of its molecular level properties has not been studied in detail. In this paper, the dynamics of poly(aspartic acid) and its sodium salt in the dilute concentration regime have been reported. The quantification of the polymer conformational properties, its solvation behavior, and the counterion dynamics are studied. The neutral polymer shows a preferentially coiled structure whereas the fully ionized polymer has an extended structure. Upon comparing with poly(acrylic acid) polymer, another polymer which has been used as a draw solute, poly(aspartic acid) forms more number of hydrogen bonds as well as fewer ion pairs.

Acetylated cellulose ethers (ACEs), a new family of cellulosic polymers, were synthesized via the esterification of hydroxyl alkyl cellulose (HAC). The average molecular weight of the ACEs was in the range 220–280 kDa, much higher by an order of magnitude than that of cellulosic polymers commonly used for membrane materials, thereby giving rise to better physical and chemical properties than conventional cellulosic polymers. Dense ACE membranes were first prepared to study fundamental transport behaviors in terms of the permeability, the apparent diffusion coefficient and the solubility coefficients of water and salt (e.g., NaCl). The water permeability and salt passage in ACE membranes were comparable with other cellulosic polymers such as cellulose acetate (CA) and cellulose triacetate (CTA), based on the trade-off relation between water permeability and water/salt selectivity. Novel ACEs showed good solubility in common organic solvents such as dimethylformamide (DMF), dimethylacetamide (DMAC), and N-methyl-2-pyrrolidone (NMP), leading to easy membrane fabrications in various membrane structures, e.g., ACE thin-film composite (TFC) membranes (as a selective thin layer), and microporous asymmetric ACE membranes (as a microporous supporting layer). In this study, such various membrane structures were investigated by using novel cellulosic polymers, ACEs, and then they were evaluated for potential desalination applications such as reverse osmosis (RO) and forward osmosis (FO).

Amphiphilic organic/inorganic hybrid star-shaped polymers (SPP) were prepared by atom transfer radical polymerization (ATRP) using poly(ethylene glycol) methyl ether methacrylate (PEGMA) and 3-(3,5,7,9,11,13,15-heptacyclohexyl-pentacyclo[9.5.1.1³,⁹.1⁵,¹⁵.1⁷,¹³]-octasiloxane-1-yl)propyl methacrylate (MA-POSS) as monomers and octakis(2-bromo-2-methylpropionoxypropyldimethylsiloxy)-octasilsesquioxane (OBPS) as an initiator. Star-shaped polymers (SPM) having PEGMA and methyl methacrylate (MMA) moieties were also prepared for comparative purposes. Polysulfone (PSf) ultrafiltration membranes coated with the SPP showed higher bio- and oil-fouling resistance and flux-recovery ability than the bare PSf membrane. Moreover, the SPP-coated membranes exhibited better antifouling properties than the SPM-coated membrane when they were used for oil/water emulsion filtration. The dual effective antifouling properties of the SPP were ascribed to the simultaneous enrichment of hydrophilic PEG and hydrophobic POSS moieties on the membrane surfaces resulting in the decrease in interactions with proteins and the increase in repellence to oils.

Due to its simple process and low energy consumption, forward osmosis (FO) has gained significant attention in the fields of portable hydration bags, desalination, landfill leachate treatment, and brine concentration. However, current state-of-the-art reverse osmosis (RO) membranes show relatively low water fluxes in FO processes due to high internal concentration polarization (ICP) and high mass transfer resistance in commercially available microporous support membranes. In this study, carboxylated polysulfones (CPSFs) were synthesized via direct polysulfone (PSF) functionalization and considered as hydrophilic, mechanically stable microporous support membranes. The incorporation of hydrophilic groups into hydrophobic polymer backbones often reduces mechanical strength due to excessive water swelling. However, the mechanical properties of CPSFs (degree of substitution, DS=0.49–0.85) were similar to those of pristine PSF, and they retained their hydrophilic nature. Microporous CPSF membranes were prepared in various conditions, and FO water fluxes and salt passages of polyamide thin-film/CPSF composite membranes were measured and compared with each other. CPSF-based FO membranes showed significantly higher water fluxes (water flux in FO mode: 18 L/m 2 h, salt passage: 2.2 g/m 2 h under 1 M MgCl 2 as a draw solution, active layer facing DI water) than PSF-based FO membranes (10.5 L/m 2 h, 1.5 g/m 2 h at the same conditions), which might be due to enhanced hydrophilicity and reduced ICP.

DOI: 10.1002/adma.201305862 However, strong van der Waals interactions and subsequent irreversible aggregation of the nanomaterials makes it unlikely for the assembled system to exhibit unidirectional alignment. This limitation can be overcome by employing “intelligent” (i.e., responsive) and fl exible one-dimensionally structured biomaterials. [ 11,12 ] The self-assembled structures of M13 viruses are an example; their mechanical stiffness and structural characteristics are readily controlled by manipulating the environmental pH or the type of bonding with the underlying substrate. [ 13,14 ]

A series of star-shaped block (SBC) and random (SRC) copolymers containing poly(ethylene glycol) methyl ether methacrylate (PEGMA) and methyl methacrylate (MMA) moieties were prepared by atom transfer radical polymerization (ATRP), and used as membrane coating materials to investigate the effects of polymer structure and monomer content on the antifouling properties of the membranes. Polysulfone (PSf) ultrafiltration membranes coated with SBCs showed noticeably higher bio- and oil-fouling resistance than the bare PSf membrane. In addition, the SBC-coated membranes exhibited better antifouling properties than the SRC-coated membrane during both BSA solution and oil/water emulsion filtrations. The enhanced antifouling properties of the SBC-coated membrane compared to the SRC-coated one were ascribed to the larger content of denser PEG segments on the membrane surface, resulting in decreased interactions with proteins and oils.

Star-shaped polymers were prepared by atom transfer radical polymerization (ATRP) using poly(ethylene glycol) methyl ether methacrylate (PEGMA) and methyl methacrylate (MMA) as monomers and polyhedral oligomeric silsesquioxane (POSS) as a core material. Linear copolymers from PEGMA and MMA were also prepared for comparison purposes. Polysulfone (PSf) ultrafiltration membranes coated with the star-shaped polymer showed larger fouling resistance and flux recovery than those coated with the linear-shaped polymer. The improved antifouling properties of the star-shaped polymer compared with those of the linear polymer were ascribed to its larger oxygen to carbon ratio and smaller interactive forces with proteins.