This paper describes a triple-transforming gel system (gel-sol-gel') for the first time, which is a thermo-responsive and multi- component organogel prepared by β-cyclodextrin (β-CD), diphenylamine (DPA) and ...This paper describes a triple-transforming gel system (gel-sol-gel') for the first time, which is a thermo-responsive and multi- component organogel prepared by β-cyclodextrin (β-CD), diphenylamine (DPA) and lithium chloride (LiCl) in N,N-dimethyla- cetamide (DMAC) in a suitable proportion based on the supramolecular interactions. In the triple-transfomaing gel system, a gel (gel A) could be formed by β-CD, DPA and LiCl in DMAC at room temperature based on stirring, then the gel could transform into a clear solution based on heating, and then the other gel (gel B) can be formed at a relatively high temperature (Tget, the gelation temperature by heating). The two gel states in the triple-transforming gel system have different microstructures. This gel system was characterized by OM, SEM, IR and theology.展开更多
N,N-dimethylacetamide (DMA) has been investigated extensively in studying models of peptide bonds. An all-atom MD simulation and the NMR spectra were performed to investigate the interactions in the DMA- water syste...N,N-dimethylacetamide (DMA) has been investigated extensively in studying models of peptide bonds. An all-atom MD simulation and the NMR spectra were performed to investigate the interactions in the DMA- water system. The radial distribution functions (RDFs) and the hydrogen-bonding network were used in MD simulations. There are strong hydrogen bonds and weak C-H…O contacts in the mixtures, as shown by the analysis of the RDFs. The insight structures in the DMA-water mixtures can be classified into different regions by the analysis of the hydrogen-bonding network. Chemical shifts of the hydrogen atom of water molecule with concentration and temperatures are adopted to study the interactions in the mixtures. The results of NMR spectra show good agreement with the statistical results of hydrogen bonds in MD simulations.展开更多
文摘This paper describes a triple-transforming gel system (gel-sol-gel') for the first time, which is a thermo-responsive and multi- component organogel prepared by β-cyclodextrin (β-CD), diphenylamine (DPA) and lithium chloride (LiCl) in N,N-dimethyla- cetamide (DMAC) in a suitable proportion based on the supramolecular interactions. In the triple-transfomaing gel system, a gel (gel A) could be formed by β-CD, DPA and LiCl in DMAC at room temperature based on stirring, then the gel could transform into a clear solution based on heating, and then the other gel (gel B) can be formed at a relatively high temperature (Tget, the gelation temperature by heating). The two gel states in the triple-transforming gel system have different microstructures. This gel system was characterized by OM, SEM, IR and theology.
基金This work was supported by the Doctoral Scientific Research Foundation of the Natural Science Foundation of Guangdong Province, China (No.7301567) and the Research Foundation of Guangdong Pharmaceutical University, China (No.2006YKX05).
文摘N,N-dimethylacetamide (DMA) has been investigated extensively in studying models of peptide bonds. An all-atom MD simulation and the NMR spectra were performed to investigate the interactions in the DMA- water system. The radial distribution functions (RDFs) and the hydrogen-bonding network were used in MD simulations. There are strong hydrogen bonds and weak C-H…O contacts in the mixtures, as shown by the analysis of the RDFs. The insight structures in the DMA-water mixtures can be classified into different regions by the analysis of the hydrogen-bonding network. Chemical shifts of the hydrogen atom of water molecule with concentration and temperatures are adopted to study the interactions in the mixtures. The results of NMR spectra show good agreement with the statistical results of hydrogen bonds in MD simulations.