Accession Number : ADA192978

Title :   Wetting of Functionalized Polyethylene Film Having Ionizable Organic Acids and Bases at the Polymer-Water Interface: Relations between Functional Group Polarity, Extent of Ionization, and Contact Angle with Water.

Descriptive Note : Interim rept.,

Corporate Author : HARVARD UNIV CAMBRIDGE MASS DEPT OF CHEMISTRY

Personal Author(s) : Bain, Colin D ; Whitesides, George M ; Holmes-Farley, Stephen R

PDF Url : ADA192978

Report Date : Mar 1988

Pagination or Media Count : 89

Abstract : This paper examines the wetting by water of low density polyethylene film modified at the polymer water (air) interface by introduction of polar organic functional groups (carboxylic acids, amines, and others). Water/polymer contact angles were determined for each of these interfaces; for interfaces containing acidic or basic functional groups, the contact angle was determined as a function of the pH. The observed contact angle was related to the hydrophilicity of these functional groups: as the hydrophilicity (as measured by Hansch pi parameters) increased up to a certain point, the contact angle decreased. Beyond that point, increased hydrophilicity had little additional influence on the contact angle. The result is interpreted in terms of water adsorbed on the polar interfacial functional groups: extensive hydration of interfacial groups having large negative pi parameters moderates their effective hydrophilicity. Keywords: Polyethylene, Wettability, Ionization, Acids, Bases, Monolayers, Gold.

Descriptors :   *FILMS, *ORGANIC ACIDS, *POLYETHYLENE, *POLYMERS, ACIDS, AMINES, ANGLES, CARBOXYLIC ACIDS, HYDRATION, INTERFACES, IONIZATION, ORGANIC RADICALS, POLAR REGIONS, POLARITY, WATER, WETTING

Subject Categories : Polymer Chemistry
      Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE