Bio-based cyclodextrins(CDs)are a common research object in supramolecular chemistry.The special cavity structure of CDs can form supramolecular self-assemblies such as vesicles and microcrystals through weak interact...Bio-based cyclodextrins(CDs)are a common research object in supramolecular chemistry.The special cavity structure of CDs can form supramolecular self-assemblies such as vesicles and microcrystals through weak interaction with guest molecules.The different forms of supramolecular self-assemblies can be transformed into each other under certain conditions.The regulation of supramolecular self-assembly is not only helpful to understand the self-assembly principle,but also beneficial to its application.In the present study,the self-assembly behavior of epoxy-β-cyclodextrin(EP-β-CD)and mixed anionic and cationic surfactant system(sodium dodecyl sulfate/dodecyltrimethylammonium bromide,SDS/DTAB)in aqueous solution was studied.Morphological and particle size characterization found that the SDS/DTAB@EP-β-CD complex,as the basic building unit,self-assembled into worm-like micelles at lower temperatures and vesicles at higher temperatures.Nuclear magnetic resonance(NMR)and Fourier transform infrared spectroscopy(FT-IR)analysis revealed that the driving force for the formation of vesicles and worm-like micelles was the hydrogen bonds between EP-β-CD molecules,while water molecules played an important role in promoting vesicle formation between SDS/DTAB@EP-β-CD units.Herein,the mechanism of the morphologic transformation of SDS/DTAB@EP-β-CD supramolecular aggregates induced by temperature was elucidated by exploring the self-assembly process,which may provide an excellent basis for the development of delivery carriers.展开更多
胺类捕收剂通过吸附在云母表面而改变其亲水性,从而达到浮选的目的。当溶液浓度由1.00×10^(-5)mol/L增加到2.04×10^(-4)mol/L,捕收剂为十二胺时白云母表面接触角由46.71°增大到78.77°,而捕收剂为十二烷基三甲基溴...胺类捕收剂通过吸附在云母表面而改变其亲水性,从而达到浮选的目的。当溶液浓度由1.00×10^(-5)mol/L增加到2.04×10^(-4)mol/L,捕收剂为十二胺时白云母表面接触角由46.71°增大到78.77°,而捕收剂为十二烷基三甲基溴化铵时的白云母表面接触角由25.79°增大到65.31°,说明相同浓度条件下十二胺能更好地改变白云母表面的亲水性,使之具有疏水性。原子力显微镜观察白云母表面捕收剂吸附图也表明,捕收剂浓度为2.04×10^(-4)mol/L,相比十二烷基三甲基溴化铵,白云母表面能吸附更多的十二铵离子。应用Materials Studio 6.1软件,采用PCFF_phyllosilicates分子力场,模拟研究白云母表面的水化作用的变化。结果表明因为伯铵盐能更稳定地吸附在白云母表面,其改善白云母表面亲水性的能力强于季铵盐。从理论和实践上解释了伯铵盐能更好地改变白云母表面的亲水性,使其具有一定的疏水性,从而达到浮选的目的。展开更多
基金China Postdoctoral Science Foundation(2020M681125)National Natural Science Foundation of China(32272254,31901618)Collaborative Innovation Center of Fragrance Flavour and Cosmetics.
文摘Bio-based cyclodextrins(CDs)are a common research object in supramolecular chemistry.The special cavity structure of CDs can form supramolecular self-assemblies such as vesicles and microcrystals through weak interaction with guest molecules.The different forms of supramolecular self-assemblies can be transformed into each other under certain conditions.The regulation of supramolecular self-assembly is not only helpful to understand the self-assembly principle,but also beneficial to its application.In the present study,the self-assembly behavior of epoxy-β-cyclodextrin(EP-β-CD)and mixed anionic and cationic surfactant system(sodium dodecyl sulfate/dodecyltrimethylammonium bromide,SDS/DTAB)in aqueous solution was studied.Morphological and particle size characterization found that the SDS/DTAB@EP-β-CD complex,as the basic building unit,self-assembled into worm-like micelles at lower temperatures and vesicles at higher temperatures.Nuclear magnetic resonance(NMR)and Fourier transform infrared spectroscopy(FT-IR)analysis revealed that the driving force for the formation of vesicles and worm-like micelles was the hydrogen bonds between EP-β-CD molecules,while water molecules played an important role in promoting vesicle formation between SDS/DTAB@EP-β-CD units.Herein,the mechanism of the morphologic transformation of SDS/DTAB@EP-β-CD supramolecular aggregates induced by temperature was elucidated by exploring the self-assembly process,which may provide an excellent basis for the development of delivery carriers.
文摘胺类捕收剂通过吸附在云母表面而改变其亲水性,从而达到浮选的目的。当溶液浓度由1.00×10^(-5)mol/L增加到2.04×10^(-4)mol/L,捕收剂为十二胺时白云母表面接触角由46.71°增大到78.77°,而捕收剂为十二烷基三甲基溴化铵时的白云母表面接触角由25.79°增大到65.31°,说明相同浓度条件下十二胺能更好地改变白云母表面的亲水性,使之具有疏水性。原子力显微镜观察白云母表面捕收剂吸附图也表明,捕收剂浓度为2.04×10^(-4)mol/L,相比十二烷基三甲基溴化铵,白云母表面能吸附更多的十二铵离子。应用Materials Studio 6.1软件,采用PCFF_phyllosilicates分子力场,模拟研究白云母表面的水化作用的变化。结果表明因为伯铵盐能更稳定地吸附在白云母表面,其改善白云母表面亲水性的能力强于季铵盐。从理论和实践上解释了伯铵盐能更好地改变白云母表面的亲水性,使其具有一定的疏水性,从而达到浮选的目的。
