Asphalt Emulsion

Are Bio-Emulsifiers within REACH ?
-a modified biopolymer additive enabling new asphalt emulsion developments-

Abstract
A new modified biopolymer additive, designated as MAGIC Y, significantly improves the storage stability and workability of asphalt emulsions having a penetration ranging from 10 – 220 mm/10. The stabilizing effect is due to selective adsorption of polymer chains onto the surface of the asphalt droplets. The mechanism for adsorption is largely governed by the dipolar and hydrogen bond interactions between the polar groups of the emulsifier and the polymer chain. It is demonstrated that the breaking index is determined by the amount of cationic emulsifier used, whereas, the MAGIC Y concentration has no effect on the breaking time. Hence, breaking and storage stability of an emulsion can now be controlled more or less independently, which allows the development of new and innovative asphalt emulsion formulations with improved properties. Furthermore, bio-based emulsifier systems, which have chemical structures resembling emulsifiers present in mammals, can be used to substitute less environmentally friendly emulsifier systems. With a choline-fatty acid (stearate) based emulsifier similar properties can be achieved as with a commercially available cationic di-amine emulsifier. These developments indicate that 100% bio-based emulsifier systems are within reach, which enables the asphalt emulsion industry to deal with future and most likely more strict legislation, like the European REACH initiative, with regard to reducing the health, safety and environmental impact of chemicals. ©2008 Asphalt Emulsion Manufacturers Association

Bert Jan Lommerts and Chris Nederpel, Latexfalt b.v., P.O. Box 6, 2396 ZG Koudekerk aan den Rijn, the Netherlands
Doetze Sikkema, MXPolymers, Heimanslaan 6, Wageningen, the Netherlands

Nano-Emulsion

Preparation and Characterization of Silver Citrate Nano-emulsion and Nano-silver Film

Abstract: To prepare the nano-scale silver carboxylate emulsions and investigate their applications in the preparation of nano-scale silver films, the silver citrate emulsion was synthesized through the reaction of silver nitrate with sodium citrate in the presence of polyvinylpyrrolidone (PVP) as a surface modification agent in water. The emulsion was coated onto the surface of the PET substrate to form a thin latex layer of silver citrate. And this was followed by drying at about 100 °C. Then, the silver citrate thin film was deoxidized by aqueous ascorbic acid. Finally, a translucent silver thin film was formed on the surface of the PET substrate. Properties of the silver citrate emulsion and the silver film on the PET were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), laser particle size analysis, scanning electron microscopy (SEM), thermogravimetry(TG) ,UV-visible absorption spectroscopy, atomic force microscopy(AFM) and digital multimeter analysis. It was found that the silver citrate particle surface-modified by PVP has a nano-rod structure and homogeneous size distribution. The nano-rod was about 20 nm in diameter and 200 nm in length. For the UV-visible absorption spectrum of the thin film exhibited an absorption peak at 430 nm, the silver thin film prepared on the surface of the PET substrate was a typical nano-scale sliver film. Measurements of the sliver thin film at room temperature indicated that the silver film was electrically conductive, and the surface resistance was 2.42 k5/cm. ©2008 Trans Tech Publications, Switzerland
Keywords: Silver carboxylate; silver citrate Nano-emulsion; Silver film; Surface resistance

Li-Xin MO, Lu-Hai LI, Ya-Ling LI, Zhong-Xiao LI, Ming Wang
Lab. of Printing & Packaging Material and Technology, Beijing Institute of Graphic Communication, No.25, Xinghua Beilu, Huangcun, Daxing District, Beijing 102600, P.R.China

Applications & Industries