标题：β-Cyclodextrin supramolecular organogels induced by different carboxylic acids that exhibit diverse morphologies
作者：Li, Zhaolou ;Hao, Aiyou ;Li, Xiang
作者机构：[Li, Zhaolou ;Hao, Aiyou ] Key Laboratory of Colloid and Interface Chemistry, Shandong University, Ministry of Education, Jinan 250100, China;[Li, Xia 更多
来源：Journal of Molecular Liquids
摘要：Supramolecular organogels were developed by introducing formic (FA), acetic (AA) or propanoic acid (PA) into the system of β-cyclodextrin (β-CD) in the presence of lithium chloride (LiCl) in N,N-dimethylformamide (DMF) without heating. A common mechanism of the gel formation was clarified, namely, H-bonds exchange from DMF-β-CD complex to DMF-carboxylic acid complex resulting in the destruction of solvent shell on β-CD gelator and β-CD self-aggregation in the co-solvent. The polarities and H-bond abilities of FA, AA or PA as additive molecule influenced micro-structures and physicochemical properties of these gels. More orderly β-CD self-assembly was in PA gel, while lower crystallinity of colloidal particles was in FA gel, which were revealed by small-angle X-ray scattering (SAXS), wide-angle X-ray scattering (WAXS), Fourier transform-infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The diversity of the gels in morphology, thermostablility and mechanical strength were studied by optical microcopy (OM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and rheology. The phase diagram of the β-CD system with FA was described for such gel formation. Such an approach, by introducing an additive to manipulate sol-gel transitions, would be a potential implication in controllable stimuli-responsive materials. © 2014 Elsevier B.V.