A new type of electrorheological fluid (ERF) with high ER efficiency, low zero-field viscosity and high uniformity was synthesized by a hydrolysis method, based on modified titanium and succinic acid. The electro-responsive performance of ERF under electric field 0–3 kV mm−1 were studied in detail. In addition to traditional research methods to explore the morphology of the ER particles, we also utilized optical diffraction imaging to study the uniformity of the chain-like structure formed by the ER particles. Due to the relatively uniform size, the particles aggregate into a periodic spatial modulation structure parallel to the electric field direction and similar to a grating on the macroscopic scale, which can further manufacture liquid controllable gratings. The observed diffraction spots, up to six levels, indicate the ERFs have potential applications in the field of optics.
Dandan Men,Fei Zhou,Lifeng Hang,Xinyang Li,Guotao Duan,Weiping Cai,Yue Li
Free-standing 2D Au nanosphere array/hydrogel composite sensing films were prepared by attaching a 2D Au nanosphere array onto a polyacrylic acid (PAAc) hydrogel film, which could be used as visualized sensors. These 2D Au nanosphere array/hydrogel composite films displayed visually diffraction color and much stronger diffraction intensity due to their periodic structures and large scattering cross-section of the Au nanospheres. Their diffraction intensity was increased by more than one order of magnitude (88 times) compared to that of 2D PS sphere array/hydrogel composite films to external stimuli, which is useful for visual observation by the naked eye and further optical characterization. Such 2D Au nanosphere array/hydrogel composite films exhibit ultrahigh diffraction intensity for them to be used for the visual determination of an analyte. The presented strategy could be extended to develop different visualized sensors based on various functional hydrogel films.