Abstract
The adsorption on silica wafers of a hyperbranched, high molecular weight polyethylenimine (PEI) was investigated using reflectometry. The pH and ionic strength dependence of PEI adsorption kinetics and that of the adsorbed amount were interpreted according to the complex balance of segment/segment and segment/surface site interactions. The observed adsorption properties show significant deviations from the recently studied features of polyvinylamine adsorption on cellulose coated silicas. The different behavior can be attributed to the pronounced difference in the nonelectrostatic affinity of polyamines toward the two different types of surfaces. The role of electrostatic interactions was also characterized by electrokinetic measurements. Due to the adsorption of PEI, significant charge reversal and shift in the isoelectric point of silica wafers occur. The ζ potential−pH curves show a maximum, which can be interpreted qualitatively by the adsorption characteristics of PEI. An attempt was also made to interrelate the adsorption and electrokinetic data via comparison of different estimates of the diffuse double layer charge of the PEI/silica system.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
