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Analysis on the surface adsorption of PEO/PPO/PEO triblock copolymers by radiolabelling and fluorescence techniques
Author(s) -
Amiji Mansoor M.,
Park Kinam
Publication year - 1994
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1994.070520409
Subject(s) - poloxamer , adsorption , ethylene oxide , pyrene , copolymer , chemistry , propylene oxide , oxide , polymer chemistry , chemical engineering , polymer , organic chemistry , engineering
We have examined the adsorption of poly(ethylene oxide)/ poly(propylene oxide)/poly(ethylene oxide) (PEO/PPO/PEO) triblock copolymers (Pluronics™) on dimethyldichlorosilane‐treated glass (DDS‐glass). The surface concentration of 125 I‐labeled Pluronic F‐68(76/30/76) reached a maximum of 0.3 μg/cm 2 when the bulk concentration in the adsorption solution was 3.0 mg/mL. Above 5.0 mg/ml, the surface Pluronic F‐68 concentration started to decrease and reached 0.17 μg/cm 2 when the bulk concentration for adsorption was 10 mg/mL. The surface concentration of Pluronic F‐108 (129/56/129), on the other hand, increased to 4.0 μg/cm 2 at the same bulk concentration. Fluroscence spectroscopic studies using pyrene suggested that the Pluronic F‐68 molecules self‐associated at the bulk concentration of 5.0 mg/mL and above. Because the aggregates are expected to expose the hydrophilic PEO segments to water, they may have lower affinity to DDS‐glass. Aggregation of Pluronic F‐68 also decreases the number of individual Pluronic molecules for adsorption. Pyrene fluorescence in Pluronic F‐108 solution, however, suggests that Pluronic F‐108 molecules do not form aggregates. It appears that the high surface concentrations of Pluronic F‐108 may result from the preferential adsorption of individual molecules in multilayers. This explains the high effectiveness of Pluronic F‐108 in preventing protein adsorption and platelet adhesion when adsorbed on to be hydrophobic surface. © 1994 John Wiley & Sons, Inc.