Atomic Force Microscopy Measurement in the Lignosulfonate/Inorganic Silica System:From Dispersion Mechanism Study to Product Design  

作　　者：Jingyu Wang Yong Qian Yijie Zhou Dongjie Yang Xueqing Qiu 

机构地区：[1]School of Chemistry and Chemical Engineering,South China University of Technology,Guangzhou 510641,China [2]State Key Laboratory of Pulp and Paper Engineering,South China University of Technology,Guangzhou 510640,China

出　　处：《Engineering》2021年第8期1140-1148,共9页工程（英文）

基　　金：We gratefully acknowledge the financial support from the National Natural Science Foundation of China(21606089,21878113,and 21878114);the Guangdong Province Science and Technology Research Project of China(2017B090903003);the Guangzhou Science and Technology Research Project of China(201704030126 and 201806010139).

摘　　要：Designing and preparing high-performance lignin-based dispersants are crucial steps in realizing the value-added utilization of lignin on an industrial scale.Such process depends heavily on an understanding of the dispersion mechanism of lignin-based dispersants.Here,atomic force microscopy(AFM)is employed to quantitatively investigate the dispersion mechanism of a lignosulfonate/silica(LS/SiO_(2))system under different pH conditions.The results show that the repulsive force between SiO_(2)particles in LS solution is stronger than it is in water,resulting in better dispersion stability.The Derjaguin–Landau–Verwey–Overbeek(DLVO)formula as well as the DLVO formula combined with steric repulsion is utilized for the fitting of the AFM force/distance(F/D)curves between the SiO_(2)probe and substrate in water and in LS solution.Based on these fitting results,electrostatic and steric repulsive forces are respectively calculated,yielding further evidence that LS provides strong steric repulsion between SiO_(2)particles.Further studies indicate that the adsorbance of LS on SiO_(2)(Q),the normalized interaction constant(A),and the characteristic length(L)are the three critical factors affecting steric repulsion in the LS/SiO_(2)system.Based on the above conclusions,a novel quaternized grafted-sulfonation lignin(QAGSL)dispersant is designed and prepared.The QAGSL dispersant exhibits good dispersing performance for SiO_(2)and real cement particles.This work provides a fundamental and quantitative understanding of the dispersion mechanism in the LS/inorganic particle system and provides important guidance for the development of high-performance lignin-based dispersants.

关 键 词：LIGNIN SILICA Atomic force microscopy Dispersion mechanism Product design 

分 类 号：O636.2[理学—高分子化学] TQ172.46[理学—化学]