Data_Sheet_1_Tunable Self-Assembled Nanostructures of Electroactive PEGylated Tetra(Aniline) Based ABA Triblock Structures in Aqueous Medium.pdf

PEGylated tetra(aniline) ABA triblock structure PEG-TANI-PEG (2) consisting of tetra(aniline) (TANI) and polyethylene glycol (PEG) was synthesized by coupling the tosylated-PEG to boc-protected NH2/NH2 TANI (1) through a simple nucleophilic substitution reaction. Deprotection of 2 resulted in a leucoemeraldine base state of TANI (2-LEB), which was oxidized to stable emeraldine base (2-EB) state. 2-EB was doped with 1 M HCl to emeraldine salt (2-ES) state. FTIR, 1H and 13C NMR and UV-Vis-NIR spectroscopy, and MS (ESI) was used for structural characterization. The synthesized triblock structure exhibited good electroactivity as confirmed by CV and UV-Vis-NIR spectroscopy. Self-assembling of the triblock structure in aqueous medium was assessed by DLS, TEM, and SEM. Spherical aggregates were observed with variable sizes depicting the effect of concentration and oxidation of 2-LEB. Further, the aggregates showed acid/base sensitivity as evaluated by doping and dedoping of 2-EB with 1 M HCl and 1 M NH4OH, respectively. Future applications in drug delivery and sensors are envisaged for such tunable self-assembled nanostructures in aqueous media.

以四苯胺（tetra(aniline)，TANI）与聚乙二醇（Polyethylene Glycol，PEG）为原料，通过将甲苯磺酰化聚乙二醇与叔丁氧羰基（tert-butyloxycarbonyl，Boc）保护的双氨基四苯胺（1）经简单亲核取代反应偶联，合成了具有ABA三嵌段结构的聚乙二醇化四苯胺（PEG-TANI-PEG，2）。对产物2进行脱保护处理，得到四苯胺的隐色翠绿胺碱态（leucoemeraldine base，2-LEB）；将2-LEB氧化后可得到稳定的翠绿胺碱态（emeraldine base，2-EB），随后以1 mol/L盐酸对2-EB进行掺杂，得到翠绿胺盐态（emeraldine salt，2-ES）。采用傅里叶变换红外光谱（Fourier Transform Infrared Spectroscopy，FTIR）、氢核磁共振波谱（¹H NMR）、碳核磁共振波谱（¹³C NMR）、紫外-可见-近红外光谱（UV-Vis-NIR）以及电喷雾电离质谱（MS(ESI)）对产物结构进行了表征。经循环伏安法（Cyclic Voltammetry，CV）与紫外-可见-近红外光谱验证，所合成的三嵌段聚合物展现出良好的电活性。通过动态光散射（Dynamic Light Scattering，DLS）、透射电子显微镜（Transmission Electron Microscopy，TEM）与扫描电子显微镜（Scanning Electron Microscopy，SEM）对该三嵌段结构在水介质中的自组装行为进行了评估，观测到尺寸各异的球形聚集体，其粒径变化体现了2-LEB的浓度与氧化状态对自组装的调控作用。进一步研究表明，该聚集体具有酸碱响应敏感性：分别采用1 mol/L盐酸与1 mol/L氢氧化铵对2-EB进行掺杂与去掺杂实验，即可验证其酸碱响应特性。这类可精准调控的水相自组装纳米结构，在药物递送与传感领域具备良好的应用前景。