Synthesis of Optically Complex, Porous, and Anisometric Polymeric Microparticles by Templating from Liquid Crystalline Droplets

2016-10-25
Wang, Xiaoguang
Büküşoğlu, Emre
Miller, Daniel S
Pantoja, Marco A. Bedolla
Xiang, Jie
Lavrentovich, Oleg D
Abbott, Nicholas L
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 extracted to yield polymeric particles. It is found that LC droplets exhibiting bipolar, radial, axial or preradial configurations template the formation of spindle-shaped, spherical, spherocylindrical or tear-shaped polymeric microparticles, respectively. Each type of microparticle exhibits distinct optical signatures indicating the presence of an internal LC-templated, anisotropic polymer network. In addition, by using a microfluidic system to generate monodisperse LC droplets containing 10%-40% wt/wt of RM257, spindle-shaped microparticles with tailored aspect ratios ranging from 2.4 to 1.2 are formed. The mass density of spherical microparticles templated from radial LC droplets can be tuned to range from 0.2 to 0.6 g cm(-3), revealing the introduction of porosity (confirmed by electron microscopy) with a volume-average pore diameter of 39 +/- 16 nm (obtained from nitrogen sorption isotherms).
ADVANCED FUNCTIONAL MATERIALS

Suggestions

Synthesis of New Thienylene Pyrrole Monomers and Their Electropolymerizations
Eken, Serap; Carbas, Buket Bezgin; Akdağ, Akın; Önal, Ahmet Muhtar (The Electrochemical Society, 2014-01-01)
In this study, four new 2,5-dithienylpyrroles (SNS) 1-(3-fluoro-phenyl)-2,5-di(thiophen-2-yl)-1H-pyrrole (m-FPTP), 1-(3-chlorophenyl)-2,5-di(thiophen-2-yl)-1H-pyrrole (m-ClPTP), 1-(3-bromo-phenyl)-2,5-di(thiophen-2-yl)-1H-pyrrole (m-BrPTP) and 1-(4-bromo-phenyl)-2,5-di(thiophen-2-yl)-1H-pyrrole (p-BrPTP) containing meta and para substituted benzene ring at the nitrogen atom were synthesized via Paal-Knorr condensation of 1,4-di(2-thienyl)-1,4-butanedione with corresponding halo-substituted anilines. The mon...
Synthesis of a regular polymer containing pseudo-polyether cages
Cihaner, A; Önal, Ahmet Muhtar (Elsevier BV, 2005-04-20)
A new compound consisting of 2-thienyl units linked by polyether bridge has been synthesized and its electrochemical polymerization was performed via constant potential electrolysis (CPE) in an electrolytic solution containing 0.1 M tetrabutylammonium hexafluorophosphate (TBAPF(6)) dissolved in CH3CN. Chemical polymerization was carried out using FeCl3 as oxidizing agent. It is found that both methods gave the same polymer product without any cleavage of the polyether bridge between thiophene (Th) rings. Al...
Synthesis and characterization of a new soluble conducting polymer and its electrochromic devices
Sahin, Elif; Sahmetlioglu, Ertugrul; Akhmedov, Idris M.; Tanyeli, Cihangir; Toppare, Levent Kamil (Elsevier BV, 2006-10-01)
A new polythiophene derivative was synthesized by both chemical and electrochemical oxidative polymerization of 1-(perfluorophenyl)-2,5-di(2-thienyl)-1H-pyrrole (FPTPy). The structures of both the monomer and the soluble polymer were elucidated by nuclear magnetic resonance (H-1-NMR) and fourier transform infrared (FTIR). Polymer of FPTPy was also synthesized via potentiostatic electrochemical polymerization in acetonitrile (AN)/NaClO4/LiClO4 (0.1 M:0.1 M) Solvent-electrolyte couple. Characterizations of th...
Investigation of structural, electronic, magnetic and lattice dynamical properties for XCoBi (X: Ti, Zr, Hf) Half-Heusler compounds
Surucu, Gokhan; IŞIK, MEHMET; CANDAN, ABDULLAH; Wang, Xiaotian; Güllü, Hasan Hüseyin (Elsevier BV, 2020-06-15)
Structural, electronic, magnetic, mechanical and lattice dynamical properties of XCoBi (X: Ti, Zr, Hf) Half-Heusler compounds have been investigated according to density functional theory and generalized gradient approximation. Among alpha, beta and gamma structural phases, gamma-phase structure has been found as the most stability characteristics depending on the calculated formation enthalpies, energy-volume dependencies and Cauchy pressures. Energy-volume plots of possible magnetic orders of gamma-phase ...
Characterization of Ge nanocrystals embedded in SiO2 by Raman spectroscopy
Serincan, U; Kartopu, G; Guennes, A; Finstad, TG; Turan, Raşit; Ekinci, Y; Bayliss, SC (IOP Publishing, 2004-02-01)
Ge nanocrystals formed in a SiO2 matrix by ion implantation were studied by Raman spectroscopy. It is shown that Raman analysis based on the phonon confinement model yields a successful explanation of the peculiar characteristics resulting from the nanocrystals. A broadening and a shift in the Raman peak are expected to result from the reduced size of the crystals. Asymmetry in the peak is attributed to the variations in the size of the nanocrystals. These effects were observed experimentally for the Ge nan...
Citation Formats
X. Wang et al., “Synthesis of Optically Complex, Porous, and Anisometric Polymeric Microparticles by Templating from Liquid Crystalline Droplets,” ADVANCED FUNCTIONAL MATERIALS, pp. 7343–7351, 2016, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/37144.