Monolayers of poly(amido amine) dendrimers on mica - In situ streaming potential measurements

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• 作者：Aneta Michna^a ; ^{ncmichna@cyf-kr.edu.pl" class="auth_mail" title="E-mail the corresponding author} ; Zbigniew Adamczyk^a ; ^{ncadamcz@cyf-kr.edu.pl" class="auth_mail" title="E-mail the corresponding author} ; Kamila Sofińska^a ; ^{ncsofins@cyf-kr.edu.pl" class="auth_mail" title="E-mail the corresponding author} ; Katarzyna Matusik^b ; ^{kasiamatusik@gmail.com" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Poly(amido amine) dendrimers of generation 8 ; PAMAMG8 ; Streaming potential of dendrimer monolayers ; AFM ; Electrophoretic mobility of dendrimers
• 刊名：Journal of Colloid and Interface Science
• 出版年：2017
• 出版时间：1 January 2017
• 年：2017
• 卷：485
• 期：Complete
• 页码：232-241
• 全文大小：1621 K

文摘

The deposition of poly(amido amine) dendrimers on mica at various pHs was studied by the atomic force microscopy (AFM) and in situ streaming potential measurements. Bulk characteristics of dendrimers were acquired by using the dynamic light scattering (DLS) and the laser Doppler velocimetry (LDV). The hydrodynamic radius derived from DLS measurements was 5.2 nm for the ionic strength of 10⁻² M and pH range 4–10. The electrophoretic mobility, the zeta potential and the number of electrokinetic charges per molecule were derived as a function of pH from the LDV measurements. It was revealed that the dendrimers are positively charged for pH up to 10. This promoted their deposition on negatively charged mica substrate whose kinetics was quantitatively evaluated by direct AFM imaging and streaming potential measurements interpreted in terms of the electrokinetic model. The desorption kinetics of dendrimers under flowing conditions from monolayers of various coverage was also studied. It was revealed that dendrimer deposition was partially reversible for pH above 5.8. The acid-base properties of the dendrimer monolayers deposited on mica were characterized.