The Study of Detergency Observed by the Quartz Microbalance Method (QCM)

We have been studying the detergency processes of various soils mainly by using quartz microbalancemethod. The method uses The 9mhz quartz crystal oscillator in water to measure a minute weight改变μg order model soils attached on the gold electrode of the oscillator. Absorption of atrace amount of a substance in the soil decreases the frequency by 1hz /ing. Removal of the soilincreases the frequency to the same extent. Thus，我们可以measure the detergency process as swelling and the following removal of the soil with time.我们研究模型protein soils by surfactants，oxidizing agents and proteases before studying the removal of lipid soils. With model lipidswe have reported the mechanism of the removal by adding alkali and surfactants.This study extendslipid detergency study to the effects of adding lipase and oxidizing agent. the processes ofremoval of model lipid soils, tripalmitin, trimiristin and lard in the presence of a lipase，Lipex and ani…onic and non-ionic surfactants, DBS and APE, respectively，were studied in a solution of pH 7 at 30 - C. Synergies of the lipase and the surfactants wereobserved. The removal was enhanced in The presence of The lipase and DBS at The concentrations farbelow the cmc，但它suppressed above the cmc of DBS. On the other hand，removal was enhanced in the presence of the lipase and APE at the concentrations above the cmc.The reasons for these synergies discussed. In terms of The negative charges endowed to Thelipid layer and the lipase by DBS micellboth become repulsirve. In terms of the drophobicity endowed to the lipid layer and the lipase byAPE micell, both become attractive.As for oxidizing agent，the addition resulted in the enhanced swelling of the model soils. Afterward，the lipid soils become faster to be removed. This means that oxidizing agent attacks the lipideffectively to oxidize，resulting in the enhanced swelling of the lipid layer by increasing the hydrophilicity. Less

We have been studying the detergency processes of various soils mainly by using quartz microbalance method. The method uses the 9 MHz quartz crystal oscillator in water to measure a minute weight changes of μg order model soils attached on the gold electrode of the oscillator. Absorption of a trace amount of a substance in the soil decreases the frequency by 1Hz/ing. Removal of the soil increases the frequency to the same extent. Thus, we can measure the detergency process as swelling and the following removal of the soil with time. We had studied the removal of model protein soils by surfactants, oxidizing agents and proteases before studying the removal of lipid soils. With model lipids, we have reported the mechanism of the removal by adding alkali and surfactants.This study extends the lipid detergency study to the effects of adding lipase and oxidizing agent. The processes of removal of model lipid soils, tripalmitin, trimiristin and lard in the presence of a lipase, Lipex and ani … More onic and non-ionic surfactants, DBS and APE, respectively, were studied in a solution of pH 7 at 30゜C. Synergies of the lipase and the surfactants were observed. The removal was enhanced in the presence of the lipase and DBS at the concentrations far below the cmc, but it was suppressed above the cmc of DBS. On the other hand, the removal was enhanced in the presence of the lipase and APE at the concentrations above the cmc. The reasons for these synergies were discussed. In terms of the negative charges endowed to the lipid layer and the lipase by DBS micell, both become repulsirve. In terms of the hydrophobicity endowed to the lipid layer and the lipase by APE micell, both become attractive.As for oxidizing agent, the addition resulted in the enhanced swelling of the model soils. Afterward, the lipid soils become faster to be removed. This means that oxidizing agent attacks the lipid effectively to oxidize, resulting in the enhanced swelling of the lipid layer by increasing the hydrophilicity. Less