Synthesis of Liquid Crystal Templated Polymeric Microparticles Shaped by Microwells


Kocaman C., Akdeniz B., Büküşoğlu E.

Eastern Mediterranean Chemical Engineering Conferences 9, Ankara, Türkiye, 30 Ağustos - 01 Eylül 2018, ss.1

  • Basıldığı Şehir: Ankara
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.1

Özet

We aimed to develop a new method for the synthesis of liquid crystal templated microparticles. In this study, polydimetylsiloxane (PDMS) masks which have protrusions in micro dimensions were used to template polyvinylalcohol (PVA) microwells. The liquid crystal mixtures of a reactive mesogen (RM257) and a nonreactive liquid crystal (E7) were filled into PVA microwells. The solution was then photopolymerized using a UV light source. After polymerization, microparticles were collected by dissolving PVA microwell mold in water. We characterized the configurations of the LCs and found that two LC defects analogous to the boojum defects in bipolar LC droplets were obtained in LCs confined in circular microwells. After photopolymerization, the particles were subjected to an extraction of the unreacted LCs using ethanol. This step allowed the microparticles to shrink and maintain a hyperbolic paraboloid (saddle) shaped particles consistent with the initial anchoring conditions at the interfaces of the microwells and anisotropic shrinkage of similar systems.[1] Characterization of the particles synthesized at different conditions were done by using polarized microscope.

 

We aimed to develop a new method for the synthesis of liquid crystal templated microparticles. In this study, polydimetylsiloxane (PDMS) masks which have protrusions in micro dimensions were used to template polyvinylalcohol (PVA) microwells. The liquid crystal mixtures of a reactive mesogen (RM257) and a nonreactive liquid crystal (E7) were filled into PVA microwells. The solution was then photopolymerized using a UV light source. After polymerization, microparticles were collected by dissolving PVA microwell mold in water. We characterized the configurations of the LCs and found that two LC defects analogous to the boojum defects in bipolar LC droplets were obtained in LCs confined in circular microwells. After photopolymerization, the particles were subjected to an extraction of the unreacted LCs using ethanol. This step allowed the microparticles to shrink and maintain a hyperbolic paraboloid (saddle) shaped particles consistent with the initial anchoring conditions at the interfaces of the microwells and anisotropic shrinkage of similar systems.[1] Characterization of the particles synthesized at different conditions were done by using polarized microscope.