Shishkanova T V, Matejka P, Král V, Sedenková I, Trchová M, Stejskal J
Department of Analytical Chemistry, Institute of Chemical Technology, 166 28 Prague 6, Czech Republic.
Anal Chim Acta. 2008 Aug 29;624(2):238-46. doi: 10.1016/j.aca.2008.07.001. Epub 2008 Jul 9.
Repeated depositions of polyaniline (PANI) have been used to control the thickness of the polymeric film deposited on poly(vinyl chloride) (PVC) membrane surface. The oxidation of aniline was carried out in a dispersion mode, i.e. in the presence of poly(N-vinylpyrrolidone) (PVP). Two kinds of PVC were used for this purpose: a non-plasticized PVC for the study of PANI deposition and PVC, plasticized with nitrophenyl octyl ether (NPOE), as a prototype of a liquid membrane electrode. The results of UV-visible and FTIR spectroscopies and electron microscopy showed that (1) the film thickness increased by about equal increments of approximately 40 nm after each polymerization, and (2) the interface with PVC was constituted by PANI film and adhering PANI-PVP colloidal particles. The various thicknesses of the deposited PANI films affected the potentiometric response of the NPOE/PVC membrane with and without an anion-exchanger. The potentiometric anionic response was observed with a minimal thickness of PANI film on the blank NPOE/PVC membrane. Sensitivity of the PANI film to pH occurred only with a blank NPOE/PVC membrane coated with a thick polymeric film, while it was strongly suppressed by the presence of a lipophilic anion-exchanger, tridodecylmethylammonium chloride (TDDMACl), in the membrane, regardless of the thickness of the polymer film. The thickness of the PANI film did not affect the anionic selectivity pattern of TDDMACl-based membranes to any great extent, but its presence improved and stabilized their potentiometric characteristics (sensitivity, linear-response range).
聚苯胺（PANI）的重复沉积已被用于控制沉积在聚氯乙烯（PVC）膜表面的聚合物膜的厚度。苯胺的氧化以分散模式进行，即在聚（N-乙烯基吡咯烷酮）（PVP）存在下进行。为此使用了两种PVC：一种是用于研究PANI沉积的未增塑PVC，另一种是用硝基苯基辛基醚（NPOE）增塑的PVC，作为液膜电极的原型。紫外可见光谱、傅里叶变换红外光谱和电子显微镜的结果表明：（1）每次聚合后，膜厚度增加约40nm的相等增量；（2）与PVC的界面由PANI膜和附着的PANI-PVP胶体颗粒构成。沉积的PANI膜的不同厚度影响了有和没有阴离子交换剂的NPOE/PVC膜的电位响应。在空白NPOE/PVC膜上，当PANI膜厚度最小时观察到电位阴离子响应。PANI膜对pH的敏感性仅在涂有厚聚合物膜的空白NPOE/PVC膜上出现，而当膜中存在亲脂性阴离子交换剂氯化三（十二烷基甲基）铵（TDDMACl）时，无论聚合物膜的厚度如何，这种敏感性都受到强烈抑制。PANI膜的厚度在很大程度上不影响基于TDDMACl的膜的阴离子选择性模式，但其存在改善并稳定了它们的电位特性（灵敏度、线性响应范围）。
