The antifogging properties of mosquito compound eyes (see figure) result from their elaborate superhydrophobic surface structure, which consists of hexagonally non-close-packed nipples at the nanoscale and hexagonally close-packed hemispheres at the microscale. A soft-lithography approach is adopted to fabricate artificial compound eyes for exploring the effects of the hierarchical micro- and nanostructure on surface hydrophobicity.

We describe a flexible method for preparing monodisperse silica-polystyrene core-shell microspheres. In this method, silica nanoparticles grafted with 3-(trimethoxysilyl)propyl methacrylate (MPS) were employed as seeds in an emulsion polymerization. The thickness of the shells could be changed through varying the amount of the monomer. The monodispersity and diameters of the core-shell microspheres were found to depend on the size of the grafted silica nanoparticles and the concentration of emulsifier. In addition, we investigated the formation mechanism of the core-shell microspheres.

Hybrid optical films of TiO₂-triethoxysilane-capped polythiourethane (TCPTU) with high refractive indices have been prepared via an in situ sol-gel method. The high refractive index triethoxysilane-capped polythiourethane (TCPTU) was synthesized by polyaddition of the triethoxysilane-modified trimercaptothioethylamine (TMTEA) and 2,2′-dimercaptoethylsulfide (MES) with 2,4-tolylene diisocyanate (TDI). The titania content in the hybrid films can be adjusted from 0 to 80 wt.-% by the feed ratio of titania precursor [Ti(OBu)₄] to polymer (TCPTU). Both FTIR and DSC analyses indicate that there is chemical bonding between the titania domain and the polymer chain. TGA results suggest that the titania of high content was successfully incorporated into polymer matrices and this series of hybrid films have good thermal properties. AFM measurements indicate that in the hybrid films the titania domains are of nanosize scale and the domain size averagely decreases from 60–80 nm to 5–20 nm with increasing content of titania, and the variation of surface roughness for the hybrid films has the same trend. These may be relative to the content of TCPTU and the interaction between titania and polymer (TCPTU). The refractive indices of the hybrid films at 632.8 nm increased from 1 632 to 1 879 as the titania content varied from 0 to 80 wt.-%.

A series of novel high refractive index episulfide-type optical resins were prepared by ring-opening copolymerization of bis(β-epithiopropylthioethyl) sulfide (BEPTES) with episulfide derivative of diglydicyl ether of bisphenol A (ESDGEBA) and 2,4-tolylene diisocyanate (TDI), respectively, in the presence of triethylamine as a curing catalyst. The episulfide monomers, BEPTES and ESDGEBA, were synthesized from their corresponding epoxy compounds, respectively. The cured transparent resins exhibit high refractive index (n_d > 1.63) and relatively low dispersion. The refractive index (n_d) and Abbe's number (ν_d) of the BEPTES/ESDGEBA curing system increased linearly with the weight content of BEPTES monomer in the range from 1.633 and 34.0 for the copolymer with 10 wt % of BEPTES to 1.697 and 38.1 for the homopolymer of pure BEPTES. For the BEPTES/TDI curing system, the refractive index and Abbe's number varied linearly with the molar ratio of BEPTES to TDI from 1.652 and 28.7 to 1.669 and 34.6. High glass-transition temperatures (T_g > 130°C) of the cured BEPTES/TDI resins were observed, which indicate that the cured BEPTES/TDI resins possess a good heat resistance. The optical, physical, and thermal properties of the episulfide-type cured optical resins were also discussed in this study. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2426–2430, 2003