Molecular ordering in a liquid crystalline material visualized by scanning electron microscopy

Spatial and Orientational Templating of Semiconducting Polymers in a Cholesteric Liquid Crystal

“…Since the effect is absent in a uniform nematic host (where the polymer network exhibits orientational order onlyÐsee Figs. 1b,2b), and, according to previous observations, [1,2,13] does not occur in an undistorted cholesteric host, it must arise from a spatially periodic distortion of the director field n ® (r ® ) associated with the F state. A connection between the distribution of polymer (described by a spatially varying volume fraction U(r ® )) and the director profile n ® (r ® ) can be obtained by minimizing the free energy density, f(n ® , U), for a composite system consisting of a LC (average molecular volume v 0 ) and small, isotropic polymer droplets (volume v 1 ).…”

Yarn ball polymer microstructures: A structural transition phenomenon induced by an electric field

“…A method that approaches this ambitious goal focuses on photopolymerization of reactive monomers, which possess an intrinsic liquid crystal phase ͑often referred to as reactive mesogens͒. 2,3 The well-known techniques to establish monolithic order in low molecular weight liquid crystals based on their susceptibility to external fields and sensitivity to surface interactions, can be used to capture sophisticated ordered molecular architectures in thin polymer films. Tailored planar films created from reactive mesogens have recently become an inconspicuous passive optical element in liquid crystal displays to resolve their long-standing viewing angle problem.…”

Ordered Polymer Microstructures Obtained Using Pattern Forming States of a Cholesteric Liquid Crystal as Templates

“…The ultimate goal is the sameÐthe integration of inorganic and organic components to create a new material whose properties are distinct from the sum of its parts. The synthesis of PMOs is based on the hydrolytic polycondensation of an alkoxysilane with bridging organic groups [(R¢O) 3 Si] n R located in the microphase-separated domains of a lyotropic liquid crystal template. In essence, the structure of the templating mesophase is ªpetrifiedº as a skin of polymerized organosilicate.…”

“…The pure silica archetype of the PMOs is periodic mesoporous silica, MCM-41. [3] This material is formed using the precursor (EtO) 4 Si. In this case, the surfactant templating mesophase is imbibed within the void spaces of the periodic mesoporous silica product.…”

“…Removal of the surfactant by solvent extraction, ion-exchange or calcination and its subse-quent replacement, through host±guest inclusion chemistry, by an organic [4] or inorganic [5] polymer, yields a periodic mesostructured silica±polymer nanocomposite material, which can subsequently be transformed to a periodic mesostructured silica±ceramic hybrid. [5] The use of a mononuclear alkoxysilane precursor, (EtO) 3 SiR, in the self-assembly surfactant-based synthesis leads to an organic functionalized mesoporous silica hybrid material, in which organic groups are terminally bonded to the silica walls and suspended within the channel space. [6] Mesoporous organosilicas of this genre enable ªchemistry in the channelsº and facilitate the development of ªsmart nanocompositesº that can function, for example, as a heavy metal sponge, a nacre mimic or a chiral separation stationary phase.…”