Conformation of polyesters adsorbed on solid surfaces

Abstract

The conformation of a polyester, poly(ethylene o‐phthalate), of relatively low molecular weight was studied after adsorption. The extension of the adsorbed molecule in a poor solvent on several planar metal surfaces was studied by ellipsometry and the fraction p of attached groups on colloidal silica particles in a good solvent was determined by the shift in the infrared absorption frequency between free and adsorbed carbonyl groups. In contrast to previously reported results for polystyrene, the extension normal to the surface remained constant (∼70 A.) while the concentration of polymer in the adsorbed film increased during the adsorption period. The value of p (0.34 for MW = 5400) is relatively high and was independent of surface population for the range of solution concentrations measured. Differences between these results and those for polystyrene are interpreted as resulting from differences in interaction energy and chain stiffness.

Thermal Properties of PMMA on Silica Using Temperature‐Modulated Differential Scanning Calorimetry

“…They obtained values of bound fractions from 0.3 to 0.4 for adsorbed poly(lauryl methacrylate) on silica in organic solvents . Similar results were obtained when poly(ethylene ortho‐phthalate) was adsorbed on silica in CCl 4 based on ellipsometric measurements . Results from ESR (which are similar to NMR) measurements were, however, higher than (in the range of 1 to 0.5) from IR over a similar range of concentrations, consistent with the notion that the estimation of bound fraction depends on different experimental technique used .…”

Charakterisierung adsorbierter makromolekülschichten durch ellipsometrie

“…I n einigen Adsorptionssystemen ist es jedoch moglich, neben der adsorbierten Menge die Zahl der Haftstellen pro adsorbiertes Makromolekul zu bestimmen8-15). Bei einigen anderen Systemen gelang es, die Dicke der Adsorptionsschicht sowie deren Konzentration zu ermitteln und daraus zu Aussagen uber die Konformation des adsorbierten Makromolekuls zu gelangen [16][17][18][19]. Daruber hinaus bietet die Adsorptionsenthalpie und deren Abhangigkeit von der Bedeckung einen weiteren Hinweis fur die Konformationsanderungen der adsorbierten Molekule20).…”

Adsorption of Block Copolymers from Selective Solvents on Curved Surfaces

“…(a) If we assume that the first term in the square brackets in eq 7 is larger than the second, then we get (9) (b) If we assume that the repulsion between the blocks (second term in eq 7) is the dominant factor in the spreading of the drops, then we obtain (10) On the basis of these expressions, we define a new parameter ∈, the polymeric control parameter, to be N B /N A 11/6 in the first limit (eq 9), or N B /N A 5/6 in the second limit (eq 10). In both these equations, Ψ is a correction term that depends only on the monomeric interfacial energies and on the particular geometry of the adsorption morphologies.…”

“…[6][7][8][9][10][11] Moreover, the polymer adsorption is facilitated by an interaction-multiplier effect, which is unique to chain molecules. [12][13][14] Any interaction that occurs with one segment is multiplied by the large number of identical segments in the macromolecule to generate a large intermolecular effect.…”