【作者】 翟春阳；

【导师】 杜玉扣；

【作者基本信息】 苏州大学 ， 物理化学， 2009， 硕士

【摘要】 (1)合成了不同代数的PAMAM树状大分子,作为制备贵金属纳米粒子的保护剂,高代数的PAMAM大分子比低代数的PAMAM保护效果好,制得的纳米粒子颗粒更均匀,粒径也更小。改变PAMAM的代数,或者改变其与纳米粒子的摩尔比,均可以在水溶液中制得不同粒径的Au、Ag和Pt贵金属纳米粒子。（2）用1,8-萘二甲酸酐修饰1.0G PAMAM,得到了化合物1GN。以1GN做保护剂,制备了稳定的Au、Ag纳米粒子;与1.0G PAMAM相比,1GN作保护剂制备的纳米粒子分散性更好,粒子也更均匀;Au、Ag纳米粒子的存在对1GN的荧光有淬灭的作用。（3）合成了易溶于水且具有很强荧光特性的4GN树状大分子。pH的变化对4GN荧光强度影响很大;Cu²⁺的存在会导致4GN荧光淬灭,而Ce³⁺的存在会导致4GN荧光增强。4GN同样可以用来制备稳定的Ag纳米粒子,Ag纳米粒子也会引起4GN荧光强度改变。（4）以PAMAM树状大分子为保护剂,在水溶液中制备了不同粒径的CdS纳米粒子。分别考察了PAMAM的代数以及保护剂与CdS物质的量比对CdS纳米粒子大小及荧光性能的影响。（5）用溶胶-凝胶法制备了易于固液分离的TiO₂-Fe₃O₄/AC磁性光催化剂。通过在紫外光照射下降解亚甲基蓝评价其光催化降解能力。结果表明:负载22% Fe3O4的光催化剂（含20 % TiO₂和58 % AC）的光催化活性最强（120 min时亚甲基蓝的降解率达到87 %,是纯TiO₂的2.7倍）;磁性光催化剂通过磁分离回收具有较高的循环使用效率。更多还原

【Abstract】 (1) Different generations of PAMAM were firstly synthesized and employed to stabilize noble mental nonaparticles （Au、Ag and Pt） in an aqueous-solution. The sizes of nonaparticles were effected by the generations of PAMAM dendrimers and the molar ratio of PAMAM to noble mental nonaparticles.（2） 1,8-naphthalimide-labelled polyamidoamine dendrimer （1GN） was synthesized and employed to stabilize Au and Ag nanoparticles. Compared with the first generations polyamidoamine dendrimer （1.0G PAMAM）, Au and Ag nanoparticles protected by 1GN had smaller size and distributed more evenly. Owing to the chromophore of 1, 8-naphthalimide, Au and Ag nanoparticles were marked via fluorescence.（3） 1,8-naphthalimide-labelled polyamidoamine dendrimer （4GN） whose has good solubility in water and fluorescence character was synthesized and employed to stabilize Ag nanoparticles and design for ionic detection. The results have shown clearly that Ag nanoparticles could be effect the fluoresence intensity. Its ability to detect ions has been evaluated in an aqueous-solution by monitoring the quenching and enhancement of different metal ions have been tested: Cu²⁺ and Ce³⁺. In addition, it has been shown that for 4GN in an aqueous-solution, the fluoresence intensity is pH dependant, hence could find application as a detector of harmful pH changes in the environment.（4） CdS nanoparticles capped with PAMAM dendrimer have been prepared in an aqueous-solution. The sizes and fluorescence properties of CdS nanoparticles were effected by the generations of PAMAM dendrimers and the molar ratio of PAMAM to CdS.（5） Active carbon（AC） loaded magnetic photocatalyst, TiO₂-Fe₃O₄/AC, were prepared by sol-gel method. The photocatalytic activity was evaluated by degradation of methylene blue in aqueous solution under the irradiation of UV light. The results indicated that the magnetic photocatalyst（loading 20 % TiO₂ and 58 % AC）loading 22% Fe3O4 in mass ratio showed the highest photocatalytic activity （ The photo-degradation yield upon methylene blue after 2 h reached 87 %, being 2.7 times higher than that of pure TiO₂ ）. The magnetic photocatalyst can be separated from the system and cycled utilization by applying magnetic field.更多还原