Wang Cheng-Chien, Chen An-Liu, Chen I-Han
Department of Chemical and Material Engineering, Southern Taiwan University of Technology, Tainan 710, Taiwan.
J Colloid Interface Sci. 2006 Jan 15;293(2):421-9. doi: 10.1016/j.jcis.2005.06.065. Epub 2005 Aug 3.
Chelating poly(acrylates-co-2-methylacrylic acid 3-(bis-carboxymethylamino)-2-hydroxy-propyl ester) microspheres of diameter 250-310 nm were prepared by the soap-free emulsion polymerization method for varying amounts of GMA-IDA. Then CdS/copolymer composite was generated by chemical deposition on the surface of the copolymer microspheres. By XRD analysis it is found that the chelated CdS nanoparticles are a pure cubic zinc blende structure. The CdS/copolymer composite is examined by UV-vis absorbance, photoluminescence, and TEM observation. Average CdS nanoparticle size calculated from Henglein's empirical curve is in the range of 3.0-8.0 nm and varies according to the GMA-IDA molar ratio during polymerization, pH value during chelation, and postchelation annealing temperature. Higher ratio of chelating group, pH value, and annealing temperature produce larger CdS nanoparticles. As GMA-IDA ratio increases, photoluminescence exhibits a red shift from 510 to 520 nm, photoluminescence increases, and bandwidth decreases. Photoluminescence of the CdS nanoparticle becomes negligible when diameter exceeds 5 nm.
通过无皂乳液聚合法制备了直径为250 - 310 nm的螯合型聚（丙烯酸酯 - 共 - 2 - 甲基丙烯酸3 - （双 - 羧甲基氨基） - 2 - 羟丙酯）微球，用于不同量的甲基丙烯酸缩水甘油酯 - 亚氨基二乙酸（GMA - IDA）。然后通过化学沉积在共聚物微球表面生成硫化镉/共聚物复合材料。通过X射线衍射（XRD）分析发现，螯合的硫化镉纳米颗粒为纯立方闪锌矿结构。通过紫外 - 可见吸收光谱、光致发光和透射电子显微镜（TEM）观察对硫化镉/共聚物复合材料进行了研究。根据亨格莱茵经验曲线计算得出的平均硫化镉纳米颗粒尺寸在3.0 - 8.0 nm范围内，并根据聚合过程中的GMA - IDA摩尔比、螯合过程中的pH值以及螯合后退火温度而变化。较高的螯合基团比例、pH值和退火温度会产生更大的硫化镉纳米颗粒。随着GMA - IDA比例的增加，光致发光呈现从510到520 nm的红移，光致发光增强，带宽减小。当直径超过5 nm时，硫化镉纳米颗粒的光致发光变得可以忽略不计。
