Enhanced Electrorheological Response of Cellulose: A Double Effect of Modification by Urea-Terminated Silane

Abstract

Abstract:As a natural polymer with abundant sources, cellulose was one of the earliest applied electrorheological (ER) materials. However, cellulose-based ER materials have not attracted much attention because of their relatively low ER effect and sensitivity to water. In this study, cellulose rods were decorated with a urea-terminated silane, 1-(3-(trimethoxysilyl) propyl) urea, after being swelled in sodium hydroxide solution. The morphologies and structures of the cellulose particles were investigated using scanning electron microscopy, Fourier-transform infrared spectroscopy and X-ray diffraction, confirming the dramatic differences of the treated cellulose particles from the pristine cellulose. Rheological behaviors of the pristine and modified cellulose particles in silicone oil were observed using a rotational rheometer. It was found that the silane-modified cellulose showed higher ER effect and higher dielectric properties than the pristine cellulose particles, which was not only related to the grafted polar molecules but may also be associated with the porous morphologies of the treated cellulose particles.

Preparation of Cellulose/Laponite Composite Particles and Their Enhanced Electrorheological Responses

“…The composite particles of cellulose/Laponite are formed via the regeneration of cellulose in alkali solution. Because of the fast precipitation and vigorous stirring, the regenerated cellulose particles easily form porous structures with rough surfaces which has been observed in previous study [ 37 ]. Herein, the composite particles of cellulose/Laponite shown in Figure 1 c are flake-like with larger particle size than raw cellulose.…”

“…This may be due to the moisture that is absorbed in the interlayer of Laponite. After compounding, the main peaks of the composite are at 2θ = 12.1°, 19.9° and 21.8°, indicating that, after alkali treatment, cellulose I transforms into the form of cellulose II [ 37 ]. The sharp peak observed in the XRD pattern of Laponite at 2θ = 4.4° disappears, which means the cellulose chains are intercalated into the interlayers of clays.…”

Transformation of Cellulose via Two-Step Carbonization to Conducting Carbonaceous Particles and Their Outstanding Electrorheological Performance

“…Sci. 2022, 23,5477 pristine cellulose is at least 220 °C, and that when the temperature is only (210 °C), almost no transformation occurs and the XRD pattern of such m close to the XRD pattern of pristine cellulose. The XRD pattern of the HTC lose sample exhibited broad diffraction peaks, indicating the amorphous c sample.…”

“…Therefore, the ER fluids based on cellulose derivatives utilized as an anhydrous dispersed phase are prioritized. Liu et al combined cellulose and laponite into composite particles leading to values of yield stress of 150.1 Pa at an electric field of strength 2 kV mm −1 [22], and modified cellulose with urea for even higher yield stresses of over 270 Pa in the same field and a mass fraction of 15 wt% in anhydrous ER fluids [23]. Cellulose can also be prepared in various forms, such as nanocrystals and nanofibers [13], microfibrillated [24], microcrystalline [25], etc.…”

Semi-conducting microspheres formed from glucose for semi-active electric field-responsive electrorheological systems

“…Biopolymers have obtained considerable attention due to their sustainability, biodegradability, non-toxicity, and also their favorable price. 14 The most famous biopolymer found in plant cell wall is unequivocally cellulose composed of glucose units linked by a glycosidic bond. Glucose, being the cheapest and the most abundant carbohydrate, has been already investigated by many researchers as a carbon-rich product of hydrothermal carbonization, so-called hydrochar.…”