Estrela-Lopis Irina, Leporatti Stefano, Typlt Elke, Clemens Daniel, Donath Edwin
Institute of Medical Physics and Biophysics, Leipzig University, D-04103 Leipzig, Germany.
Langmuir. 2007 Jun 19;23(13):7209-15. doi: 10.1021/la700496c. Epub 2007 May 22.
Polyelectrolyte capsules were fabricated by layer-by-layer deposition of poly(styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) on glutardialdehyde fixed human erythrocytes and subsequent core dissolution using NaOCl as an oxidizing agent. SANS together with confocal laser scanning microscopy (CLSM) were applied to study capsule topology and interior as well as the layer thickness as a function of the deposition protocol, layer number, ionic concentration, and temperature treatment. The capsules contained various amounts of trapped polyelectrolyte. Retention depended on the order of polyelectrolyte deposition and layer number, which influenced layer permeability. The capsule wall thickness was found to be much smaller (3-4.5 nm in total) than what was known for polyelectrolyte multilayer walls, where every single layer contributes about 1.8 nm to the total thickness. NaCl (0.1 mM) caused a layer thickness decrease by 16%. Annealing at 70 degrees C induced capsule shrinking together with an increase of the wall thickness by 85% and wall density by 12%.
通过在戊二醛固定的人红细胞上逐层沉积聚苯乙烯磺酸盐（PSS）和聚烯丙胺盐酸盐（PAH），随后使用次氯酸钠作为氧化剂进行核心溶解，制备了聚电解质胶囊。采用小角中子散射（SANS）和共聚焦激光扫描显微镜（CLSM）来研究胶囊的拓扑结构、内部情况以及作为沉积方案、层数、离子浓度和温度处理函数的层厚度。这些胶囊含有不同量的截留聚电解质。保留情况取决于聚电解质沉积顺序和层数，这会影响层的渗透性。发现胶囊壁厚度比聚电解质多层壁的已知厚度小得多（总共3 - 4.5纳米），在聚电解质多层壁中，每一层对总厚度的贡献约为1.8纳米。0.1 mM的NaCl使层厚度降低了16%。在70摄氏度下退火导致胶囊收缩，同时壁厚度增加85%，壁密度增加12%。
