Fraction of H-bonded segments of N-ethylpyrrolidone, oligomeric and polymeric vinylpyrrolidone adsorbed from CHCl3 on silica measured by IR spectrometry

Abstract

Abstract:The adsorption of N-ethylpyrrolidone (NEP), oligomeric and polymeric vinylpyrrolidone (OVP, PVP) on silica (Aerosi1200) from CHC13 solution is investigated by IR spectrometry. The influence of the annealing temperature of the silica on the adsorbed amount and on the fraction of adhered segments was studied. The dependences of the amount adsorbed on solution concentration result for NEP in a Langmuir isotherm for OVP and PVP in high affinity isotherms. The fraction of adhered H-bridged carbonyl groups determined by compensation procedures, the fraction of surface SiOH groups occupied and the mukiple interaction quotient Q show different dependences on the amount adsorbed for the measured adsorptives, indicating different interactions of the monomeric segments with the surface groups. This behaviour is explained by comparing the amount adsorbed in saturation with monolayer capacities, surface concentration of SiOH groups and frequency shifts. A splitting of the band of the bound carbonyl groups in a double peak was observed with OVP and PVP, referring to an additional interaction of polymer segments neighboured to specifically bound segments.

Attenuated Total Reflection Fourier Transform Infrared Spectroscopy Study of Poly(methyl methacrylate) Adsorption on a Silica Thin Film: Polymer/Surface Interactions

“…Infrared spectroscopy has been extensively used for the study of the adsorption of organic species onto high surface area silica. − For example the formation of the hydrogen bonds between polymers containing carbonyl groups − and the surface sites of dispersed silica has been studied by this technique. On the contrary, in the attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy studies about polymer adsorption, − the characterization of the polymer/surface interactions only results from the investigation of the polymer bands, and the silanol bands are not studied.…”

Suspension Polymerization of Styrene with Pickering Emulsifiers

“…A rapid approach to the adsorption equilibrium within two hours was also observed by Killmann and Bergmann with the same PVP sample and with Aerosil 200 as solid. [31] The formation of adsorption plateaus for PVP with an exponential rise at lower PVP concentrations was also observed by Killmann and Bergmann, [31] Parnas et al [32] and Esumi et al [33] …”

Infrared spectroscopic investigations of the adsorption of ethylene oxide–propylene oxide copolymers from CCl4on pyrogenic silica

“…Q = 1 means that one SiOH group is interacting with one ether segment, EO or PO, of the polymers. 26 In table 2 a comparison is shown of the p fractions at full coverage (6 = 1) and at low coverage (6 -+ 0). The The ratio pOH,m is the total available number of surface SiOH groups related to the total number of adsorbed segments.…”