Dynamic Light Scattering and Zeta Potential of a Leather Finishing System

摘要

Finishing is one of the significant steps in the process by which the tanning industry transforms leather into an end-product. Therefore, a deep study of the finishing system is necessary to help the control of this step and bring innovation to the finishing process. Based on principles of dynamic light scattering (DLS) and zeta potential, the stability of a leather finishing system was investigated. Polyurethane and acrylic resin were used to prepare a single finishing system and wax emulsion, silicone oil and pigment paste were added to the single finishing system to make three binary finishing systems, then a ternary system was prepared by adding wax emulsion and silicone oil to the single finishing system.The particle size and zeta potential of the single, binary and ternary finishing systems were characterized using the Zetasizer Nano-ZS (Malvern Instruments Ltd., UK). The results showed that the stability of the finishing system was not affected with the addition of wax emulsion and silicone oil, because the zeta potential was always greater than 30mv, however; a significant decrease of zeta potential was observed due to the addition of pigment to the finishing system, which indicates a decrease of the finishing system's stability. The results provide a comprehensive and theoretical understanding of the interactions among materials in a finishing system.