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This paper presents a bio-inspired adaptive micro-lens with electrically tunable focus made of non-ionic high-molecular-weight polyvinyl chloride (PVC) gel. The optical device mimics the design of the crystalline lens and ciliary muscle of the human eye. It consists of a plano-convex PVC gel micro-lens on Indium Tin Oxide (ITO) glass, confined with an annular electrode operating as an artificial ciliary muscle. Upon electrical activation, the electroactive adhesive force of the PVC gel is exerted on the annular anode electrode, which reduces the sagittal height of the plano-convex PVC gel lens, resulting in focal length variation of the micro-lens. The focal length increases from 3.8 mm to 22.3 mm as the applied field is varied from 200 V/mm to 800 V/mm, comparable to that of the human lens. The device combines excellent optical characteristics with structural simplicity, fast response speed, silent operation, and low power consumption. The results show the PVC gel micro-lens is expected to open up new perspectives on practical tunable optics.

Flame retardant polypropylene (PP) composites were prepared by combining random polypropylene with uncoated and surface-treated forms of magnesium hydroxide filler and elastomeric modifiers, with and without maleic anhydride functionalization. Four types of magnesium hydroxide (MDH) with different surface treatments were compounded at amounts up to 60% by weight to PP/polyolefin elastomer (POE) matrix resin to obtain a series of composites. The tensile strength and elongation at break were measured. MDH coated with polymeric material was found to give a high elongation at break value compared with the values obtained with uncoated and vinyl silane and amino silane coated MDH. Two types of POE, i.e., neat and maleic anhydride grafted POE (POEgMA), were used to investigate the stress whitening of composites in bending deformation. POEgMA used composites showed no stress whitening while neat POE used composites showed whitening when bended.

Nanocomposites of polypropylene with organically modified clays were compounded in a twin-screw extruder by a two-step melt compounding of three components, i.e., polypropylene, maleic anhydride grafted polypropylene (PPgMA), and organically modified clay. The effect of PPgMA compatibilizers, including PH-200, Epolene-43, Polybond-3002, and Polybond-3200, with a wide range of maleic anhydride (MA) content and molecular weight was examined. Nanocomposites' morphologies and mechanical properties such as stiffness, strength, and impact resistance were investigated. X-ray diffraction patterns showed that the dispersion morphology of clay particles seemed to be determined in the first compounding step and the further exfoliation of clays didn't occur in the second compounding step. As the ratio of PPgMA to clay increased, the clay particles were dispersed more uniformly in the matrix resin. As the dispersibility of clays was enhanced, the reinforcement effect of the clays increased; however, impact resistance decreased.

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