Janus fabrics with superamphiphilicity were fabricated via electrospinning of polyacrylonitrile (PAN). PAN nanofibrous mats were formed on an aluminum foil substrate and then thermally treated to cause hydrolysis. An identical PAN solution was subsequently electrospun onto the hydrolyzed PAN layer, followed by peeling off of the bicomposite film from the collector substrate to produce a free-standing Janus fabric. On one side, the electrospun PAN mat exhibited superhydrophobic properties, with a water contact angle of 151.2°, whereas the initially superhydrophobic PAN sheet on the opposite side of the fabric was converted to a superhydrophilic surface (water contact angle of 0°) through hydrolysis of the surface functional groups induced by the thermal treatment. The resulting Janus fabrics exhibited both superhydrophobicity, repelling water on the one side, and superhydrophilicity, absorbing water on the other side. The organic solvent resistance of the PAN nanofibrous sheets was remarkably improved by incorporation of a tetraethyl orthosilicate. This facile and simple technique introduces a new route for the design and development of functional smart, robust fabrics from an inexpensive, commercially available polymer.

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Purpose -The purpose of this paper is to develop environmentally stable near-infrared (NIR)-absorbing windows by blending an NIR-absorbing dye and a thermally-crosslinkable polymer. Design/methodology/approach -To enhance the environmental stability of the NIR-absorbing window, a poly(vinyl phenol-co-methyl methacrylate) (poly(VP-co-MMA)) prepolymer and a poly(melamine-co-formaldehyde) (PMF) cross-linking agent were mixed, and thermal crosslinking was performed under mild conditions (1008C). Findings -The resistance of the crosslinked hybrid films to heat, humidity, and ultraviolet radiation damage improved dramatically relative to the pristine NIR-absorbing dye. The improved environmental stability of the crosslinked NIR hybrid film resulted from the reduced free volume and restrictions in the molecular thermal dynamic motions of the polymer due to the presence of the crosslinked network surrounding the NIR-absorbing dye molecules. Originality/value -The methods provided a novel, simple, and practical solution to improving environmentally stability of NIR-absorbing window.