FTIR-ATR spectroscopic analysis of bis-crown-ether based PVC-membrane surfaces

摘要: Model membranes have been prepared from PVC (65 mg), dioctyl sebacate (120 mg) and the crown ether BME-44 (4 in 2 ml THF solution analyzed by molecular-specific surface technique Attenuated Total Reflectance (ATR) infrared region order to better understand complexation reactions at interface between membrane aqueous solutions of NaCl, KCl, KSCN NH4SCN. The information depth provided this method was 0.1 3 μm could be changed variation angle incidence IR-radiation. study carried out ex-situ (at dried surfaces) after contact times 1 h with 0,1–2 M subsequent rinsing H2O for 0–100 s. It found that KSCN- NH4SCN-contact results significant complex formation membrane, whereas KCl course NaCl do not react such a way (under diffusion into bulk membrane). Through experimental evidence forms only outmost membrane. This cannot penetrate because lipophobic nature Cl−. These findings support “space-charge effect” model explanation potential generation since electrochemical behaviour electrode described is nearly equal low concentrations (−58.5 mV/decade) while it loses its sensitivity (not KCl) higher concentrations.