Green and High Effective Scale Inhibitor Based on Ring-Opening Graft Modification of Polyaspartic Acid

Polyaspartic acid (PASP)-based green scale inhibitor has great potential application in water treatment. Here, we first synthesized PASP in ionic liquid. Then, an effective PASP-based green scale inhibitor was synthesized by ring-opening graft modification of PASP with both aspartic acid (ASP) and monoethanolamine (MEA). Its chemical composition was characterized by gel chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), and 1H nuclear magnetic resonance (1H NMR). Scale inhibition efficiency was measured by static scale inhibition tests. The results showed that the new PASP-based scale inhibitor has high scale inhibition to both CaCO3 and Ca3(PO4)2. When the concentration was increased to 2 mg/l, the inhibition efficiency of the new PASP-based scale inhibitor was 99% for CaCO3, while when the concentration was raised to only 4 mg/l, its inhibition efficiency increased to 100% for Ca3(PO4)2. Scanning electronic microscopy (SEM) and X-ray diffraction (XRD) were used to analyze the changes of crystal structure for CaCO3 and Ca3(PO4)2 after adding the new PASP-based scale inhibitor. The crystal size of CaCO3 and Ca3(PO4)2 became smaller and the crystal form became amorphous after adding the modified PASPs compared with adding pure PASP. Moreover, the modified PASP showed good biodegradation performance.

Preparation of Carbon Fiber-Polyacrylamide Composite Hydrogel Based on Surface Electric-Initiated Polymerization

Conductive hydrogels have shown excellent application prospects in the fields of bioelectronics, tissue engineering, wearable devices, etc. However, its poor compatibility at the organic-inorganic interface affects its mechanical strength and limits its wide application. We prepared carbon fiber-polyacrylamide organic-inorganic composite material by electrochemical polymerization using N,N-methylenebisacrylamide as the crosslinking agent, acrylamide as the monomer, and carbon fiber as the conductive filler. It forms a conductive hydrogel after absorbing water. The effects of monomer concentration, reaction time, and current on the composite material were investigated in this article. The experimental results show that a large number of irregular bumps are produced on the surface of carbon fiber, and various characterization tests show that it is polyacrylamide (PAM) that successfully attached to carbon fiber. Under the same electrochemical polymerization time, the current density and monomer concentration have little effect on the molecular weight which mainly concentrated around 6.2 × 105. The graft modification of PAM reduces the defects on the surface of the carbon fiber, and the composite effect is good.

Graft modification in bamboo cellulose nanofibrils: An effective option to improve compatibility and tunable surface energy

In this work, from an endemic and non-significant value-added bamboo argentine, nanofibrils (CNFs) of 20 nm in width were obtained. These nanofibrils were chemical modified in surface with three simple steps using a noncommercial low molecular weight polylactic acid. The success of modification was confirmed by FTIR, TGA, DSC and XRD analysis. The modified nanofibrils were taken up for changing surface properties in films based on commercial PLA. The results show that dispersive (γ D/S) component of films increase of 34.7 mN/m to 36.1 mN/m after the addition of modified nanofibrils from 2 to 5% in formulation of the films, comparing with a physical blend. Interesting others result in physical, mechanical, and thermal properties of the nanocomposites, were reported.

Study on the graft modification mechanism of macroporous silica gel surface based on silane coupling agent vinyl triethoxysilane

Study on the mechanism of the alkylation reaction on the surface of porous silica gel.