ISSN:
1435-1536
Keywords:
ABA block copolymers
;
free liquid films
;
dynamic method for surface force measurement
;
steric stabilization
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The thinning of foam films from aqueous solutions of an ABA triblock copolymer of polyethylene oxide and polypropylene oxide (average molecular weight 14,000 g/mol) is studied experimentally. The dependence of the surface forces on film thickness is obtained by the dynamic method of Scheludko and Exerowa. The total surface force measured in foam films (radius ≈ 60–70 μm) from 10−5 M (0.014 wt%) polymer solution with 0.1 M NaCl is positive at thicknesses from about 800 Å down to 460 Å. The electrostatic repulsion is negligible while the contribution of van der Waals attraction is small (within 15%). Therefore a positive surface force component predominates. Most probably it arises from steric interactions between the hydrophilic polyethylene oxide tails of the polymer. The dynamic method appears to be a suitable technique for exploring the stabilization of foam films from ABA copolymers.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00657642
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