Microscopic protonation equilibria of poly(amidoamine) dendrimers from macroscopic titrations
Microscopic protonation equilibria of poly(amidoamine) dendrimers from macroscopic titrations
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DOI：
10.1021/ma0300241
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发表时间：
2003-06-03
期刊：
影响因子：
5.5
通讯作者：
Borkovec, M
中科院分区：
文献类型：
--
作者：
Cakara, D;Kleimann, J;Borkovec, M
用酸碱电位滴定法研究了G 0、G1、G2、G3、G4和G6代聚酰胺-胺（PAMAM）树枝状大分子。解释的数据与网站结合模型，它提供了可能性，模拟所有代的树枝状聚合物的滴定曲线，并在一个共同的参数集内描述所有的树枝状聚合物。这些参数涉及微观电离常数为每个组在完全去质子化状态和最近邻对相互作用参数。从这个模型我们可以进一步得到所有的微观电离常数以及条件微观态概率。质子化。PAMAM树枝状聚合物的质子化首先涉及在高pH下树枝状聚合物外缘处的伯胺基团的质子化，而树枝状聚合物核心中的叔胺基团在较低pH下质子化。
Poly(amidoamine) (PAMAM) dendrimers of generations G0, G1, G2, G3, G4, and G6 are investigated by potentiometric (acid-base) titrations. The data are interpreted with a site binding model, which offers the possibility to model the titration curves for all generations of the dendrimers and to describe all dendrimers within a common parameter set. These parameters involve the microscopic ionization constants for each group in the fully deprotonated state and nearest-neighbor pair interaction parameters. From this model we can further obtain all microscopic ionization constants as well as conditional microstate probabilities. The protonation. of PAMAM dendrimers first involves protonation of primary amine groups at the outer rim of the dendrimer at high pH, while the tertiary amine groups in the dendrimer core protonate at lower pH. The last group to protonate at low pH is a central tertiary amine.