Kelly Kristopher D, Schlenoff Joseph B
Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States.
ACS Appl Mater Interfaces. 2015 Jul 1;7(25):13980-6. doi: 10.1021/acsami.5b02988. Epub 2015 Jun 16.
Thin films of complexes made from oppositely charged polyelectrolytes have applications as supported membranes for separations, cell growth substrates, anticorrosion coatings, biocompatible coatings, and drug release media, among others. The relatively recent technique of layer-by-layer assembly reliably yields conformal coatings on substrates but is impractically slow for films with thickness greater than about 1 μm, even when accelerated many fold by spraying and/or spin assembly. In the present work, thin, uniform, smooth films of a polyelectrolyte complex (PEC) are rapidly made by spin-coating a polyelectrolyte coacervate, a strongly hydrated viscoelastic liquidlike form of PEC, on a substrate. While the apparatus used to deposit the PEC film is conventional, the behavior of the coacervate, especially the response to salt concentration, is highly nontraditional. After glassification by immersion in water, spun-on films may be released from their substrates to yield free-standing membranes of thickness in the micrometer range.
由带相反电荷的聚电解质制成的复合物薄膜可作为支撑膜用于分离、细胞生长基质、防腐涂层、生物相容性涂层和药物释放介质等。相对较新的逐层组装技术能够在基底上可靠地形成保形涂层，但对于厚度大于约1μm的薄膜来说，即使通过喷涂和/或旋涂组装加速许多倍，其速度仍然慢得难以实际应用。在本工作中，通过在基底上旋涂聚电解质凝聚层（一种高度水合的类粘弹性液体形式的聚电解质复合物），快速制备出薄的、均匀的、光滑的聚电解质复合物（PEC）薄膜。虽然用于沉积PEC薄膜的设备是传统的，但凝聚层的行为，特别是对盐浓度的响应，是非常非传统的。通过浸入水中进行玻璃化处理后，旋涂的薄膜可以从其基底上剥离，得到厚度在微米范围内的独立膜。
