| The X-ray, known as Roentgen ray, has been widely used in medicine because of the high energy and penetrability. Besides, it also brought a serious problem that it may hurt the health workers and patients. As such, it’s an urgent issue to develop a kind of X-ray shielding materials with high effectiveness, practicability and cheapness.The microcapsule is a kind of tinny particles with core-wall structure, which makes the core isolated and reduces the mass transfer between environment and microcapsule. In this dissertation, the lead salt was cladded by EC or PVA to prepare microcapsules and then composited with BC to develop an X-ray shielding material which has high shielding efficiency, high security and low cost. The detail researches are as follows:(1) Prepared the Pb(NO3)2/EC microcapsules by W/O/W composite emulsion evaporate method. The optimal condition to prepare Pb(NO3)2/EC microcapsules is as follow:the wall/core ratio (Rw/c) is5:5, the gelatin concentration of external water phase is5wt%, the evaporating temperature (Te) is70℃. The Pb content of microcapsules prepared under the optimal condition is364mg/g. The cumulative release of Pb from microcapsules in90days is about8-12%.(2) Prepared the Pb(NO3)2/PVA microcapsules by W/O reverse microemulsion method. The optimal condition to prepare Pb(NO3)2/PVA microcapsules is as follow:Rw/c=5:2.5, the addition of span80is1ml and the GA is2ml. The Pb content of microcapsules prepared under the optimal condition is449.1mg/g. The cumulative release of Pb from microcapsules, which is influenced by the GA addition, in90days is about0.52%.(3) The microcapsule/BC composite films prepared by pulping and filtering with good flexibility and mechanical strength can meet the application requirements. Besides, the aluminum equivalent (Al) of microcapsule/BC composite films would be greater than1mm which can meet the requirements of GBZT147-2002and GB16757-1997for the X-ray shielding clothes. |
PDF Full Text Request