Effect of catalyst on formation of poly(methyl methacrylate) brushes by surface initiated atom transfer radical polymerization

Poly （methyl methacrylate） （PMMA） brushes were synthesized from silicon wafers via surface initiated atom transfer radical polymerization （SI-ATRP）. Energy disperse spectroscopy （EDS） and atomic force microscopy （AFM） confirmed that PMMA brushes were successfully prepared on the silicon wafers, and the surface became more hydrophobic according to the contact angle of 69~. It is found that CuCI/1, 1, 4, 7, 10, 10-hexamethyl triethylenetetramine （HMTETA） system is more suitable than CuBr/N, N, N′, N″, N′″-pentamethyl diethylenetriamine （PMDETA） system to control the free radical polymerization of MMA in solution. Nevertheless, better control on the thickness of PMMA brushes was achieved in CuBr/PMDETA than in CuC1/HMTETA due to higher activity and better reversibility of the former system.

酸增殖剂及其应用

基于自催化酸解反应的酸增殖是新的提高成像灵敏度的方法。目前发现有实用价值的酸增殖剂绝大多数为磺酸酯类化合物。本文详细介绍了酸增殖机理和酸增殖剂的种类,比较了2-甲基-2-(对甲苯磺酰氧甲基)-3-酮-丁酸叔丁酯、环己二醇二甲苯磺酸酯、三聚羟基丙醛三对甲苯磺酸酯在化学增幅抗蚀剂体系中的应用性能,认为环己二醇二碳酸酯的灵敏度高,更具有实用价值。

PDLLA/HA/NGF神经导管体内外降解研究

制备一种复合型PDLLA/HA/NGF神经导管,通过体内外降解实验,研究分析材料在体外降解过程中介质pH值、质量损耗、NGF释放等规律,以及体内降解材料微观形貌变化等,对材料的降解性能进行评价。结果表明,该复合型神经导管具有降低PDLLA的酸自催化降解速度,NGF含量也会影响材料降解性能和释放性能。从而为优化材料组成及调控降解性能提供依据。