As a new member of the 2D material family, MXene integrates high metallic conductivity and hydrophilic property simultaneously. It shows tremendous potential in fields of energy storage, sensing, electromagnetic shielding, and so forth. Due to the abundant surface functional groups, the physical and chemical properties of MXene can be tuned by the formation of MXene-polymer composites. The introduction of polymers can expand the interlayer spacing, reduce the distance of ion/electron transport, improve the surface hydrophilicity, and thus guide the assembly of MXene-polymer structures. Herein, the preparation strategies of MXene-polymer composites including physical mixing, surface modification, such as anchoring through Ti-N and Ti-O-C bonds, bonding through esterification, grafting functional groups through Ti-O-Si/Ti-O-P bonds, photograft reaction, as well as in situ polymerization are highlighted. In addition, the possible mechanisms for each strategy are explained. Furthermore, the applications of MXene-polymer composites obtained by different preparation strategies are summarized. Finally, perspectives and challenges are presented for the designs of MXene-polymer composites.
ABSTRACT:In a low emulsifier system, the MMA-BA-MAA copolymer emulsions were prepared as seed latices and the seeded emulsion polymerization of MMA-MAA-DVB was consequently carried out to prepare carboxylated core particles. The hydrophobic shell was then synthesized onto the core using styrene, acrylonitrile, and divinylbenzene as comonomers. The hollow latex particles were obtained by alkalization treatment of the core-shell latex particles. The effects of the feeding rate of monomer mixture, contents of emulsifier SDBS and crosslinking agent DVB, and ratio of the monomers during the core stage and shell stage on the morphology and volume expansion of the latex particles were investigated. The results show that the monodispersed hollow latex particles with large size can be obtained when the feeding rate is 0.1 g/min, SDBS content is 0.15 and 0.2 wt % during the core stage and shell stage, respectively, DVB contents are 1% during the preparation of shell copolymers, and the monomer ratio of the core particle to shell layer is 1 : 8.
Waterborne polyurethane/polyacrylate (PUA) emulsions were prepared by dispersing polyurethane (PU) prepolymer in polyacrylate (PA) emulsion; therefore, the PU particles formed in the presence of PA nanoparticles. The particle size and its distribution of the composite PUA emulsion were determined by dynamic light scattering. The result shows that the average particle size increases initially and then decreases with increasing PA content, which is confirmed by transmission electron microscope characterization. The surface properties of PUA films were analyzed by water contact angle and atomic force microscope topography. It indicates that the water contact angle and the average roughness of the composite PUA films are larger than those of the PU film. Meanwhile, mechanical properties test, scanning electron microscopy, and thermogravimetric analyses disclose that the PUA films are characterized by enhanced tensile strength, rough fractured surface, and good thermal stability. The preparation method proposed in this article is an effective and convenient way to manufacture composite PUA emulsion. The composite PUA emulsion can be potentially used in coatings.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.