title: Self-assembly of gelators confined within the nano-scale interlayer space of organo-montmorillonite.
abstract: The self-assembly of low molecular weight gelators confined within the nano-scale interlayer space of organo-montmorillonite is likely to be different from that under normal conditions (bulk space). Four kinds of gelators, 1-methyl-2,4-bis(N'-n-octadecylureido) benzene (MBB18), 1-methyl-2,4-bis(N'-n-dodecylureido)benzene (MBB12), bis(4'-stearamido phenyl) methane (BSM18) and bis(4'-octanamido phenyl)methane (BOM8), were used to investigate gelation of organic solvents confined within the nano-scale interlayer space of organo-montmorillonite. The possible morphologies of these gelators aggregates confined within the nano-scale space of organo-montmorillonite will be discussed in comparison with that in bulk space by employing differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Herein, two types of organogels were prepared under the same conditions. One of them was formed within the interlayer space of organo-montmorillonite and another was formed in bulk space. The XRD patterns confirm that self-assembly of gelators takes place via an unusual pathway within the confined interlayer space of organo-montmorillonite, indicating that the alkyl chains of gelators adopt a parallel arrangement and do not insert into each other. This unusual arrangement of gelators confined within the interlayer space of organo-montmorillonite does lead to the different thermal effect observed by the DSC measurements. These features ultimately strengthen the thermodynamic stability of gelator aggregates, for example MBB18, and raise the gel-to-sol transition temperature, which jumps from 60 to 123 degrees C.
authors.affiliation: School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Xiong
authors.forename: Zifu
authors.initials: Z
authors.lastname: Li
authors.forename: Guilong
authors.initials: G
authors.lastname: Feng
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Huibi
authors.initials: H
authors.lastname: Xu
authors.forename: Xiangliang
authors.initials: X
authors.lastname: Yang
authors.forename: Yajiang
authors.initials: Y
authors.lastname: Yang