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Superabsorbent polymers (SAPs) are crosslinked hydrophilic polymers that are capable of absorbing large amounts of water. Commercial SAPs are mostly produced with acrylic acid that cannot be easily biodegraded. Therefore, in this study, polysaccharide-based SAPs using carboxymethyl cellulose as a major component were prepared. Starch aldehydes and citric acid were selected due to their environment-friendly, non-toxic, and biodegradable properties compared to conventional crosslinking agents. Starch aldehydes were prepared by periodate oxidation, which forms aldehyde groups by taking the places of C–OH groups at C-2 and C-3. Furthermore, starch aldehydes were analyzed through the change in FT-IR spectra, the aldehyde quantitation, and the morphology in FE-SEM images. In the crosslinking of polysaccharide-based SAPs, the acetal bridges from starch aldehydes led to a large amount of water entering the network structure of the SAPs. However, the ester bridges from citric acid interfered with the water penetration. In addition, the swelling behavior of the SAPs was analyzed by the Fickian diffusion model and the Schott’s pseudo second order kinetics model. The relationship between swelling behavior and morphology of the SAPs was analyzed by FE-SEM images. In conclusion, polysaccharide-based SAPs were well prepared and the highest equilibrium swelling ratio was 87.0 g/g.

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This study aimed to develop a highly efficient nanofilter for capturing fine particles using electrostatic forces. Poly(vinyl alcohol) (PVA), a water-soluble synthetic polymer, was selected as the main component of the filter because it can be easily fabricated by electrospinning. Titanium dioxide (TiO 2 ) nanopowder with an anatase structure was applied to the nanofilters as it has the highest photocatalytic activity among the existing photocatalysts. PVA nanofilters fabricated by electrospinning could still be dissolved in water by hydrolysis. Therefore, heat treatment was performed to make the nanofilters stable, thereby forming CO bonds by keto−enol tautomerization. Structural changes in the PVA nanofilter before and after heat treatment were investigated by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) analysis. As the TiO 2 concentration increased, the fiber diameter of the PVA nanofilter decreased and a homogeneous fiber was obtained. The filtration efficiency and pressure drop also improved significantly, compared to those of the PVA-only nanofilter. Moreover, we observed eco-friendly decomposition of the PVA/TiO 2 nanofilter into water and carbon dioxide by a photocatalytic reaction under UV irradiation.

Liquid crystalline polymer (LCP) coatings offer avenues for the fabrication of devices with smart surfaces incorporating responsive topography, reflectivity, or polarization from their unique anisotropic optical and mechanical properties. LCPs have most commonly been made by photopolymerization of reactive mesogens within confined cells. Here, an alternative method of preparing LCP coatings using initiated chemical vapor deposition (iCVD) is described. LCP‐iCVD copolymer coatings comprised of an acrylic cyanobiphenyl mesogenic monomer copolymerized with vinyl ether crosslinkers are prepared. Systematic experiments examine the relationship between the monomer properties, reactor conditions, and polymer deposition rate. The alignment of the mesogenic phase in the as‐synthesized coatings is also demonstrated to be controlled by the surface energy of the underlying substrate. Interestingly, the surface properties of LCP coatings measured by atomic force microscopy are shown to depend on the director orientation. The data presented in this work introduce mesogenic monomers into the library of vapor‐deposited polymer coatings.