We summarize the latest electrorheological (ER) materials along with their rheological understanding, and also provide a forward-looking summary of the potential applications of ER technology.

Water-soluble polymers with high molecular weights are known to decrease the frictional drag in turbulent flow very effectively at concentrations of tens or hundreds of ppm. This drag reduction efficiency of water-soluble polymers is well known to be closely associated with the flow conditions and rheological, physical, and/or chemical characteristics of the polymers added. Among the many promising polymers introduced in the past several decades, this review focuses on recent progress in the drag reduction capability of various water-soluble macromolecules in turbulent flow including both synthetic and natural polymers such as poly(ethylene oxide), poly(acrylic acid), polyacrylamide, poly(N-vinyl formamide), gums, and DNA. The polymeric species, experimental parameters, and numerical analysis of these water-soluble polymers in turbulent drag reduction are highlighted, along with several existing and potential applications. The proposed drag reduction mechanisms are also discussed based on recent experimental and numerical researches. This article will be helpful to the readers to understand better the complex behaviors of a turbulent flow with various water-soluble polymeric additives regarding experimental conditions, drag reduction mechanisms, and related applications.

To verify the influence of the functional elements particular size for the radiation attenuation coefficients and mechanical properties radiation shielding material based on epoxy resin, we prepare two WO3/E44 samples with different particular sizes of WO3 by a solidified forming approach. The linear attenuation coefficients of these samples are measured for γ-ray photo energies of 59.6, 121.8, and 344.1 keV, etc. using narrow beam transmission geometry. It is found that the linear attenuation coefficients would increase with the decreasing particle size of the WO3 in the epoxy resin based radiation shielding material. The theoretical values of the linear attenuation coefficients and mass attenuation are calculated using WinXcom, and good agreements between the experimental data and the theoretical values are observed. From the studies of the obtained results, it is reported that from the shielding point of view the nano-WO3 is more effective than micro-WO3 in the epoxy resin based radiation shielding material.

A functional raspberry-like core–shell composite particle consisting of a conducting polyaniline (PANI) core and magnetic zinc ferrite shell is synthesized by Pickering emulsion polymerization. The morphology and chemical structure of the PANI/zinc-ferrite composite are evaluated by scanning electron microscopy, transmission electron microscopy, and Fourier-transform infrared spectroscopy. An electrorheological/magnetorheological fluid consisting of the PANI/zinc-ferrite composite dispersed in silicone oil with a particle concentration of 5 vol % is fabricated. Its rheological characteristics under external electric and magnetic fields are investigated by using a rotational rheometer. Under the electric or magnetic field, the PANI/zinc-ferrite particles form chain-like structures, demonstrating a solid-like state.