Dendritic polyesters bearing COOH groups at the focal points were grafted onto nanometer silica premodified with 3-aminopropyltriethoxysilane by N,N′-dicyclohexylcarbodiimide mediated amidation. The products were cha...Dendritic polyesters bearing COOH groups at the focal points were grafted onto nanometer silica premodified with 3-aminopropyltriethoxysilane by N,N′-dicyclohexylcarbodiimide mediated amidation. The products were characterized qualitatively by FTIR, TGA and elemental analysis. It was shown that a significant grafting （10%15% net grafting for this reaction） was obtained despite the steric hindrance of the dendrons.展开更多
An ultrathin film with forth generation poly(aminoamine)(PAMAM) dendrimers (methyl quaternary ammonium salt) as polycation and poly(sodium \%p\% styrenesulfonate) (PSS) as polyainon was fabricated \%via\% sequential d...An ultrathin film with forth generation poly(aminoamine)(PAMAM) dendrimers (methyl quaternary ammonium salt) as polycation and poly(sodium \%p\% styrenesulfonate) (PSS) as polyainon was fabricated \%via\% sequential deposition. It shows that the step by step depositions carried out smoothly by monitoring with UV Vis spectrometer. The multilayer film is rather flat with a mean roughness of \{0.39 nm\} determined by AFM. The average thickness of a bilayer is \{5.0 nm\} obtained from XRD, which indicates that the dendrimers molecules were compressed and possess high flattening.展开更多
以乙二胺为核,通过迈克尔加成反应和酯胺解反应这两个重复的步骤,合成了0.5～5.0代PAM-AM树枝状大分子,使用氢核磁共振波谱(1 H NMR)、碳核磁共振波谱(13 C NMR)和质谱(MS)等证明了树枝状大分子的结构。同时对不同代数树枝状大分子的紫...以乙二胺为核,通过迈克尔加成反应和酯胺解反应这两个重复的步骤,合成了0.5～5.0代PAM-AM树枝状大分子,使用氢核磁共振波谱(1 H NMR)、碳核磁共振波谱(13 C NMR)和质谱(MS)等证明了树枝状大分子的结构。同时对不同代数树枝状大分子的紫外及荧光性质进行了研究,发现整代树枝状大分子和半代树枝状大分子由于端基的不同,从而表现出不同的紫外吸收峰位,而紫外吸收强度与树枝状分子的分子骨架有密切的关系。虽然没有传统的荧光发射基团,但PAMAM树枝状分子却表现出特有的荧光现象,本文对PAMAM树枝状分子的荧光性质的影响因素进行了详细的研究。展开更多
文摘Dendritic polyesters bearing COOH groups at the focal points were grafted onto nanometer silica premodified with 3-aminopropyltriethoxysilane by N,N′-dicyclohexylcarbodiimide mediated amidation. The products were characterized qualitatively by FTIR, TGA and elemental analysis. It was shown that a significant grafting （10%15% net grafting for this reaction） was obtained despite the steric hindrance of the dendrons.
文摘An ultrathin film with forth generation poly(aminoamine)(PAMAM) dendrimers (methyl quaternary ammonium salt) as polycation and poly(sodium \%p\% styrenesulfonate) (PSS) as polyainon was fabricated \%via\% sequential deposition. It shows that the step by step depositions carried out smoothly by monitoring with UV Vis spectrometer. The multilayer film is rather flat with a mean roughness of \{0.39 nm\} determined by AFM. The average thickness of a bilayer is \{5.0 nm\} obtained from XRD, which indicates that the dendrimers molecules were compressed and possess high flattening.
文摘以乙二胺为核,通过迈克尔加成反应和酯胺解反应这两个重复的步骤,合成了0.5～5.0代PAM-AM树枝状大分子,使用氢核磁共振波谱(1 H NMR)、碳核磁共振波谱(13 C NMR)和质谱(MS)等证明了树枝状大分子的结构。同时对不同代数树枝状大分子的紫外及荧光性质进行了研究,发现整代树枝状大分子和半代树枝状大分子由于端基的不同,从而表现出不同的紫外吸收峰位,而紫外吸收强度与树枝状分子的分子骨架有密切的关系。虽然没有传统的荧光发射基团,但PAMAM树枝状分子却表现出特有的荧光现象,本文对PAMAM树枝状分子的荧光性质的影响因素进行了详细的研究。
