Effect of Ca ion concentration on adsorption of poly(carboxylate ether)-based (PCE) superplasticizer on mica.

Hypothesis: Poly(carboxylate ether)-based (PCE) superplasticizers consist of a carboxylic acid backbone and grafted poly(ethylene glycol) (PEG) side chains. Ca ion bridging mechanism is commonly purported to control PCE's adsorption on negatively charged cement particle surfaces in cement suspension, thus PCE was expected to adsorb on negatively charged surfaces in synthetic pore solutions via Ca/COO interactions.

Experiments: Adsorption behaviors of a commercial PCE on negatively charged mica were studied in aqueous electrolyte solutions by a surface forces apparatus.

The development of cement and concrete additive: based on xylonic acid derived via bioconversion of xylose.

The present work attempted to utilize xylose by converting it to an aldonic acid. In the present study, xylose was converted to xylonic acid by using commercial glucose oxidase enzyme, palladium catalysis, and microbial bioconversion. The enzyme conversion was successfully done using a commercial glucose oxidase.