Highly dendrite-suppressing gel polymer electrolytes for lithium metal batteries are presented utilizing perfluoropolyether-functionalized 2D boron nitride nanoflakes as a multifunctional additive.

Polyamide reverse osmosis (RO) membranes with carbon nanotubes (CNTs) are prepared by interfacial polymerization using trimesoyl chloride (TMC) solutions in n-hexane and aqueous solutions of m-phenylenediamine (MPD) containing functionalized CNTs. The functionalized CNTs are prepared by the reactions of pristine CNTs with acid mixture (sulfuric acid and nitric acid of 3:1 volume ratio) by varying amounts of acid, reaction temperature, and reaction time. CNTs prepared by an optimized reaction condition are found to be well-dispersed in the polyamide layer, which is confirmed from atomic force microscopy, scanning electron microscopy, and Raman spectroscopy studies. The polyamide RO membranes containing well-dispersed CNTs exhibit larger water flux values than polyamide membrane prepared without any CNTs, although the salt rejection values of these membranes are close. Furthermore, the durability and chemical resistance against NaCl solutions of the membranes containing CNTs are found to be improved compared with those of the membrane without CNTs. The high membrane performance (high water flux and salt rejection) and the improved stability of the polyamide membranes containing CNTs are ascribed to the hydrophobic nanochannels of CNTs and well-dispersed states in the polyamide layers formed through the interactions between CNTs and polyamide in the active layers.

A series of composite polymer electrolytes containing poly(ethylene glycol)-grafted graphene oxide fillers were prepared for all-solid-state lithium-ion battery applications.

Vinyl addition polymers of substituted norbornene (NB) monomers possess very high glass-transition temperatures, making them useful in diverse applications; however, until very recently, the lack of an applicable living polymerization chemistry has precluded the synthesis of such polymers with controlled architecture, or copolymers with controlled sequence distribution. In the present work, block and random copolymers of NB monomers bearing hydroxyhexafluoroisopropyl and n-butyl substituents (HFANB and BuNB) are synthesized via living vinyl addition polymerization, using (η3-allyl)­Pd­(i-Pr3P)Cl activated by [Li­(OEt2)2.5]­B­(C6F5)4 as the initiator. Both series of polymers are cast into the selective skin layers of thin film composite (TFC) membranes, and these organophilic membranes are investigated for the concentration of n-butanol from dilute aqueous solution via pervaporation. The block copolymers show well-defined microphase-separated morphologies, both in bulk and as the selective skin layers on TFC membranes, while the random copolymers are homogeneous. Both block and random vinyl addition copolymers are effective as n-butanol pervaporation membranes, with the block copolymers showing a better flux-selectivity balance; the optimal block copolymer, containing 19 wt % BuNB, showed a process separation factor of 21 and a flux of 4300 g m–2 h–1 with a 1.00 wt % aqueous n-butanol feed, at a selective layer thickness of 1.3 μm. While polyHFANB has much higher permeability and selectivity than polyBuNB, incorporating BuNB units into the polymer (in either a block or random sequence) limits the swelling of the polyHFANB and thereby improves the n-butanol pervaporation selectivity. An analogous block copolymer derived from ring-opening metathesis polymerization, which shows much greater swelling than the vinyl addition polymers, shows a correspondingly higher flux and lower selectivity.

water such as proteins, oils, and microorganisms is one of the major drawbacks in the membrane fi ltration because it can decrease the water permeation fl ux causing a subsequent increase in energy consumption for the fi ltration process. [ 2,3 ] Biofouling layer formed by the microorganisms on the membrane surfaces can clog and/or contaminate the membrane surfaces, thus preventing effective water purifi cation. [ 3h , 4 ] Rejection of heavy metal ions in waste water is another major concern in the membrane fi ltration process.Since membrane surface properties are key factors to the understanding and control of physico-chemical phenomena in the membrane fi ltration process, membrane surface modifi cations using blending, surface coating, and surface grafting methods have been applied to overcome the disadvantages of the process. [ 3a,d , 5 ] For example, a polymer with an ionic/ligand moiety was coated on a membrane surface to impart heavy metal ion removal properties, [ 5b ] and poly(ethylene oxide) (PEO) was incorporated into poly(acrylonitrile) (PAN) membrane by blending to enhance antifouling property against proteins. [ 3e ] Most of the membrane surface modifi cation strategies have focused on resolving one of the deleterious properties of each particular application. However, to our knowledge, any membrane surface modifi cation method to impart all the advantageous properties including the antifouling, antimicrobial, and heavy metal ion removal properties has not yet been reported.Plant-derived polyphenols have attracted signifi cant interests due to their broad chemical versatility, radical scavenging ability, metal ion complex formation, and antimicrobial properties. [ 6 ] They are easily obtained from general plants such as green tea, fruits, and fl owers, and also commercially available with low cost. [ 6a , 7 ] Polyphenol derivatives can be broadly used for surface coating applications because their catechol (1,2-dihydroxyphenyl) and/or gallol (1,2,3-trihydroxyphenyl) groups can easily adhere to the surfaces of substrates, forming covalent and/or noncovalent bonding structures. [ 5a,d , 6d , 8 ] For example, dopamine, a polyphenol derivative having the catechol moiety, has been applied as an antifouling coating material for fi ltration The membrane fi ltration process has received much attention as one of the most promising water purifi cation techniques. However, it still has several disadvantages, such as organic-, oil-, and biofouling, membrane contamination by microorganisms, and the diffi culty in rejecting heavy metal ions, which are closely related to the membrane surface properties. Various approaches have been used to prepare membranes with antifouling, antimicrobial, or heavy metal ion removal properties on their surfaces. However, membranes with all these properties have not yet been reported. It might be possible to prepare membranes with such multifunctional properties by modifying the membrane surfaces with various organic and/or inorganic functional materials using multiple chem...

Nanocomposite membrane containing CNTs and GO exhibits considerably improved performances by the synergistic combinations of CNTs and GO, which can increase the dispersity in a polymeric matrix.

The synthesis and characterization of poly­(phenylene polysulfide) networks (PSNs) with controlled average sulfur ranks, from elemental sulfur (ES) and p-diiodobenzene (DIB), are investigated. The PSN films, prepared via simple hot pressing, are found to possess large extensibility up to around 300% and complete recovery of shape and mechanical properties after deformation, which are attributed to the loosely cross-linked network structures mainly consisting of linear poly­(phenylene polysulfide) chains. The covalent polysulfide linkages in the PSNs also exhibit dynamic behaviors under ultraviolet (UV) or thermal treatment, thus, enabling self-healing and reprocessing of the films when scratched and broken, respectively. Combined with the unique mechanical properties of the PSNs, their high refractive index and excellent infrared (IR) transparency contribute to the preparation of stretchable, healable, and reprocessable IR transmitting materials for potential deformable and stretchable optical applications.

Core-shell silica particles with ion-conducting poly(ethylene glycol) and anion-trapping boron moiety in the shell layer were prepared to be used as fillers for polymer composite electrolytes based on organic/inorganic hybrid branched copolymer as polymer matrix for all-solid-state lithium-ion battery applications. The core-shell silica particles were found to improve mechanical strength and thermal stability of the polymer matrix and poly(ethylene glycol) and boron moiety in the shell layer increase compatibility between filler and polymer matrix. Furthermore, boron moiety in the shell layer increases both ionic conductivity and lithium transference number of the polymer matrix because lithium salt can be more easily dissociated by the anion-trapping boron. Interfacial compatibility with lithium metal anode is also improved because well-dispersed silica particles serve as protective layer against interfacial side reactions. As a result, all-solid-state battery performance was found to be enhanced when the copolymer having core-shell silica particles with the boron moiety was used as solid polymer electrolyte.