Design of functional materials using liquid crystals as molecular templates

Karausta, Aslı
Liquid crystal (LC) is a phase of material which is intermediate to a crystalline solid and an isotropic liquid such that the molecules flow but retain a degree of long-range orientational ordering. LCs, due to their long range orientational ordering and fluidic properties, can be used in templated synthesis of polymeric materials as well as self assembly of the microparticles incorporated into the LCs. In the first part of this thesis, we sought to provide control over alignment of the polymer chains, alignment and size of the pores within polymeric films with thickness of 20-200 m. For the synthesized polymeric materials, we used characterization methods such as thermal, optical, mechanical, nitrogen adsorption porosimetry and electron microscopy. As a result of these analysis, we found that it is possible to control both size distribution (between 5-50 nm-in-diameter) and alignment of pores, and the material exhibit alignment-dependent mechanical properties which are sufficient to be used in different applications such as separation, soft robotics, sensors and biomedical devices. In the second part of the thesis, we investigated the self-assembly of the inorganic particles of different shapes incorporated into LCs. The zeolite 4A particles used were cubic particles with truncated, sharp or round edges in a size range of 2-6 μm. The ZIF-L particles used were leave shaped particles with 400 nm thickness and 1-4 and 5-10 μm in length and width, respectively. The particles were observed to orient in a preferred direction and mediate anchoring conditions that lead to three-dimensional defect structures.


Controlled synthesis of organic-inorganic composite particles
Erçelik, Elif; Büküşoğlu, Emre; Aydoğan, Nihal; Department of Chemical Engineering (2022-8-26)
Liquid crystal (LC) is a state of matter having long-range orientational order between crystalline solid and isotropic liquid, and its molecular orientation can be altered with external stimuli. The polymerization of liquid crystal droplets has been widely used for the synthesis of LC-templated functional materials due to its ordering property and fluidic behavior. In this study, we investigated the synthesis of composite particles with controlled internal and interfacial structure using surface-modified na...
Positioning of Cubic Shaped Particles with Different Edge Structures in Nematic Medium
KARAUSTA, ASLI; Büküşoğlu, Emre (2021-01-01)
Liquid crystals (LC) are phases of matter that possess long range orientational order while maintaining fluidic properties. LCs have been shown to provide a medium that result in self-assembly of the colloidal particles through elastic interactions. One parameter that affects the positioning of the particles in LC medium is the edge sharpness of the particles. Simulation studies in the literature suggests that the edge sharpness of the particles directly affect the LC director profile at the vicinity of the...
Development of the methodology for the synthesis of bis-aminoinositols
Çokol, Nalan Korkmaz; Balcı, Metin; Department of Chemistry (2011)
Cyclitols are cyclic compounds having hydroxyl groups which attached to different carbons on the ring. Cyclitols have attracted a great deal of attention for having diverse biological activities. Cyclic alcohols play an important role in biological processes such as inhibition of glycosidase, cellular recognition, and signal transduction. In addition to this, these compounds are very important molecules due to being capable of using while synthesizing natural products or pharmaceuticals. In this study, deve...
Liquid crystal-templated synthesis of polymeric microparticles with complex nanostructures
Akdeniz, Burak; Büküşoğlu, Emre; Department of Chemical Engineering (2019)
Liquid crystals (LC), when combined with photolithography, enable synthesis of microparticles with two- and three-dimensional shapes and internal complexities. We prepared films of nematic LCs using mixtures of reactive (RM257) and non-reactive mesogens (E7) with controlled alignment of LCs at the confining surfaces, photopolymerized the RM257 using a photomask, and then extracted the unreacted mesogens to yield polymeric microparticles. The extraction resulted in a controlled anisotropic shrinkage with an ...
Synthesis of Optically Complex, Porous, and Anisometric Polymeric Microparticles by Templating from Liquid Crystalline Droplets
Wang, Xiaoguang; Büküşoğlu, Emre; Miller, Daniel S; Pantoja, Marco A. Bedolla; Xiang, Jie; Lavrentovich, Oleg D; Abbott, Nicholas L (Wiley, 2016-10-25)
It is demonstrated that aqueous dispersions of micrometer-sized liquid crystal (LC) droplets provide the basis of a general and facile methodology for the templated synthesis of spherical and nonspherical polymeric micro-particles with complex internal structure and porosity. Specifically, nematic droplets of reactive (RM257)/nonreactive mesogens with distinct internal configurations are prepared using a range of approaches, the reactive mesogens are photopolymerized, and then the nonreactive mesogens are e...
Citation Formats
A. Karausta, “Design of functional materials using liquid crystals as molecular templates,” M.S. - Master of Science, Middle East Technical University, 2018.