Flocculation of reed pulp suspensions by quaternary chitosan-nanoparticle SiO2 retention aid systems
✍ Scribed by Xiaohui Zhang; Wen Juan Gu; Houbin Li; Huang Chi; Lingyun Chen
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 526 KB
- Volume
- 117
- Category
- Article
- ISSN
- 0021-8995
No coin nor oath required. For personal study only.
✦ Synopsis
The microparticle retention aid system has been a focus on the studies of paper-making chemicals. N-(2-Hydroxy-3-trimethylammonio)-propyl chitosan chlorider [quaternary chitosan (QCS)]-nanoparticle SiO 2 dual component system was investigated in this work. The adsorpton kinetic experiments indicated that there was a very fast (<1 min) polymer adsorption under good mixing conditions. Adsorption of QCS onto the fiber surface was followed by a rearrangement to reach an equilibrium conformation. At the same time, QCS chains, existing on the surface of fiber, could permeate into the porous of the fiber, resulting in the reducing of zeta potential of the cellulosic fiber. In addition, the flocculation would be increased with the increasing of SiO 2 when the fiber substrates surfaces was net positively charged by an adsorbed QCS layer. It was also found that ionic strength decreased significantly the flocculation efficiency in pure QCS system, whereas the turbidity of the reed pulp suspension increased slightly with the increasing of NaCl concentration in QCS-SiO 2 systems. The effect of shear force on the flocculation was tested. It was shown shear led to floc breakage and decreased the flocculation. These phenomena were very obvious for one-component system (QCS or C-St), but the microparticle system (QCS-SiO 2 or C-St-SiO 2 ) was shear resistance. Dynamic drainage experiment indicated that the turbidity of white water was decreased with the increasing of dosage of SiO 2 in experimental level. V