Preparation Of Nanomether Calcium Lactate Via Chemical Precipitation Method And Lamellar Liquid Crystal Method

The purpose of the present work is to investigate the preparation methods of nanoparticles of calcium lactate, and the prepared samples of calcium lactate meet the specification stipulated in the standard on food grade in order to improve the application efficiency and additional value of calcium lactate.On the basis of comprehensive analysis on the factors to control the formation of calcium lactate nanopowder, the process flowsheets of manufacturing nanopowder were put forward using chemical precipitation method and lamellar liquid crystal method. Lactic acid and calcium hydroxide were selected as raw materials in the two different methods. So far as the chemical precipitation method, the effect of factors such as the ration of calcium hydroxide to lactic acid, operating temperature and stirring speed on the mean size of calcium lactate particle was examined by means of single factor test method, and the appropriate process conditions were determined by multi-factor orthogonal test procedure. With respect to lamellar liquid crystal method, taking the system of Triton X-100/n-C10H21OH/H2O as the templates for lamellar liquid crystal, the preparation of the nanopowder of calcium lactate was carried out, with water within single phase region for the lamellar liquid crystal replaced by aqueous solution of calcium lactate. The composition and apparent solubility of calcium lactate in lamellar liquid crystal were determined, and the appropriate process conditions were determined by single factor test method.The performance of prepared samples were detected according to corresponding standard with food grade stipulated in China, and the particle size and particle size distribution were measured by multi-angle sub-micro particle size analyzer and spectrophotometer, the purity and crystal morphology were characterized by XRD and TEM.The experimental results show that when the nanoparticles are prepared in terms of chemical precipitation method, it is necessary to make calcium lactate solution close to supersaturation solution with the aim of inhibiting the secondary nucleate, to filtrate unreacted calcium hydroxide from the mother liquor, and then to add the proper quantity of ethanol into the filtration liquor so as to increase the nucleation rate and control the crystal growth, thus increasing dispersivity of nanopowder. The agglomeration of nanopowder was inhibited by adjusting pHs of reaction system and washing the powder by washing liquid with different pHs. Nanoparticles of calcium lactate can be obtained by taking the Triton X-100/n-C10H21OH/H2O system as the templates of the lamellar liquid crystal. Using the chemical precipitation and lamellar liquid crystal method, the particle size of calcium lactate can reach 52.3 and 32.5nm, respectively, with the narrow crystal size distribution. The specification for the samples obtained by two methods meet the requirements stipulated in the standard of calcium lactate with food grade.