Topological defects in liquid crystals as templates for molecular self-assembly

2016-01-01
Wang, Xiaoguang
Miller, Daniel S
Büküşoğlu, Emre
de Pablo, Juan Jose
Abbott, Nicholas L
Topological defects in liquid crystals (LCs) have been widely used to organize colloidal dispersions and template polymerization, leading to a range of assemblies, elastomers and gels. However, little is understood about molecular-level assembly processes within defects. Here, we report that nanoscopic environments defined by LC topological defects can selectively trigger processes of molecular self-assembly. By using fluorescence microscopy, cryogenic transmission electron microscopy and super-resolution optical microscopy, we observed signatures of molecular self-assembly of amphiphilic molecules in topological defects, including cooperativity, reversibility and controlled growth. We also show that nanoscopic o-rings synthesized from Saturn-ring disclinations and other molecular assemblies templated by defects can be preserved by using photocrosslinkable amphiphiles. Our results reveal that, in analogy to other classes of macromolecular templates such as polymer-surfactant complexes, topological defects in LCs are a versatile class of three-dimensional, dynamic and reconfigurable templates that can direct processes of molecular self-assembly.
NATURE MATERIALS

Suggestions

Design Parameters and Principles of Liquid-Crystal-Templated Synthesis of Polymeric Materials via Photolithography
AKDENİZ, BURAK; Büküşoğlu, Emre (American Chemical Society (ACS), 2019-10-08)
The design parameters and principles for the synthesis of polymeric microscopic objects using a method that combines photolithography and liquid crystal (LC) molecular templates have been demonstrated. Specifically, mixtures of a reactive mesogen (RM257) and nonreactive LC (E7) were polymerized using UV light and a photomask. We used photomasks with circular, triangular, rectangular, square, star-shaped, and heart-shaped features to provide initial shapes to the objects. Then, the unreacted parts were extra...
Controlled assemble and microfabrication of zeolite particles on SiO2 substrates for potential biosensor applications
Öztürk, Semra; Turan, Raşit; Akata Kurç, Burcu (2008-12-04)
Zeolite nanoparticles were organized into functional entities on SiO2 substrates and microfabrication technique was tested to form patterns of zeolite nanoparticles on SiO2 using the electron beam lithography (EBL). The effect of different techniques for efficient zeolite assembly on the SiO2 substrates was investigated. For this purpose, three different assembly techniques were tested. The first two methods are spin-coating (SC) and ultrasound aided strong agitation (US) methods, which were tested using ba...
Shape Effects on the Structure and Response of the Polymeric Particles Synthesized from Cholesteric Liquid Crystal Templates
Avşar, Deniz Işınsu; Büküşoğlu, Emre (2021-01-01)
: Liquid crystals (LCs) have been shown to provide molecular templates for the synthesis of polymeric particles. Past studies have revealed the elastic effects to dominate internal configuration of the LC molecular templates for the sizes below 10 µm. Sacrificial microwells were used in this study to study the effect of shapes of the particles synthesized from the cholesteric liquid crystals on their structure and response. Specifically, mixtures of diacrylate based reactive (RM257) and nonreactive mesogens...
Experimental characterizations of the response of nematic liquid crystal droplets upon adsorption of nanoparticles from aqueous media
Şengül, Selin; Büküşoğlu, Emre; Aydoğan, Nihal; Department of Chemical Engineering (2021-9-08)
Nematic liquid crystal (LC) droplets have been widely used for the detection of molecular species. In this study, we investigated the response of micrometer sized nematic LC droplets against the adsorption of nanoparticles from aqueous media. In the first part of this study, we synthesized ~100 nm-in-diameter silica nanoparticles and modified their surfaces to mediate either planar or homeotropic LC anchoring and a pH-dependent charge. Secondly, we carried out the adsorption of nanoparticles to the LC-aqueo...
Processing and characterization of poly(ethylene terephthalate) based composites
Kılınç, Mert; Bayram, Göknur; Department of Chemical Engineering (2004)
Polymeric composites are any of the combinations or compositions that comprise two or more materials as separate phases, at least one of which is a polymer. By mixing a polymer with another material, such as glass, carbon, or another polymer, it is often possible to improve the desired properties of the polymer. In this study, ternary composites were prepared by using recycled poly(ethylene terephthalate), PET as the matrix material, short glass fiber (SGF) as the reinforcing filler and thermoplastic elasto...
Citation Formats
X. Wang, D. S. Miller, E. Büküşoğlu, J. J. de Pablo, and N. L. Abbott, “Topological defects in liquid crystals as templates for molecular self-assembly,” NATURE MATERIALS, pp. 106–114, 2016, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47553.