| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 608976 | Journal of Colloid and Interface Science | 2011 | 9 Pages |
The influences of pH and NaCl concentration of dipping solutions and the pH and NaCl concentration of disintegration solutions on the disintegration behaviors of poly(4-vinylpyridiniomethanecarboxylate) (PVPMC)/poly(sodium 4-styrenesulfonate) (PSS) (PVPMC/PSS) multilayer films were investigated by ultraviolet–visible spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FT-IR), quartz crystal microbalance (QCM) and atomic force microscopy (AFM). It was found that the disintegration rates and degrees of PVPMC/PSS multilayer films in neutral water could be well controlled by changing pH of dipping solutions and immersion time during the disintegration process. Furthermore, PVPMC/PSS multilayer films could be disintegrated completely and rapidly in pH 8 alkali solution or physiological condition (i.e., 0.15 M NaCl solution). The controllable disintegration of PVPMC/PSS multilayer films was then utilized to fabricate PEC/PSS free-standing multilayer films, in which PEC was a positively charged polyelectrolyte complex made from excessive poly(diallyldimethylammonium) (PDDA) and PSS. The experimental results indicated that the disintegration rates of PVPMC/PSS sacrificial sublayer strongly affected the integrity of the resultant PEC/PSS free-standing multilayer films. Only free-floating PEC/PSS was released from neutral water by disintegrating PVPMC/PSS multilayer sublayers. However, large size flat and tube-like PEC/PSS free-standing multilayer films with good mechanical properties were obtained facilely from pH 8 alkali solution and 0.15 M NaCl solution, respectively. The preparation of such free-standing films at physiological condition may be useful in the biological or medical application.
Graphical abstractControllable disintegration of polycarboxybetaine multilayer films (PVPMC/PSS) and fabrication of tube-like free-floating films from normal saline solution.Figure optionsDownload full-size imageDownload high-quality image (86 K)Download as PowerPoint slideResearch highlights► The disintegration rate and degree of PVPMC/PSS multilayer films can be well controlled. ► PVPMC/PSS multilayer films could be completely disintegrated in neutral water within 30 min. ► PVPMC/PSS multilayer films could be rapidly disintegrated in pH 8 alkali solution or 0.15 M NaCl aqueous solution within 2 min. ► Large size flat and tube-like PEC/PSS free-standing multilayer films with good mechanical properties were successfully prepared from 0.15 M NaCl aqueous solution.
