Liquid Crystal-Templated Synthesis of Anisotropic Ultrafiltration Membranes

Karausta, Aslı
Büküşoğlu, Emre
In this study, we developed a method that provides determination ofthe internal structure of the polymeric films by using LCs as template. For thesynthesis of the material, we photopolymerized the mixture of reactive(4-(3-acryloyoxypropyloxy) benzoic acid 2-methyl-1,4-phenylene ester (RM257))and non-reactive (4-cyano-4′-pentylbiphenyl (5CB)) mesogens confined in filmgeometries with thickness of 20-200 µm, and then extracted nonreactive mesogenswith solvent to yield polymeric films of area in the order of 10 cm2.When the polymer films were restricted to an area either through a mechanicalor a configurational constraint, open pores were incorporated into the films.The average diameter of the pores was found to be in the range 10-40 nm and canbe tuned by varying the reactive mesogen concentration. In fact, the averagedirection of the pores was found to be determined by the nematic director whichcan further be controlled by the functionality of the contacting surfaces. Havingcontrol over the sizes and directions of the pores has enabled the material tobe involved in many application areas. We found that the range of the poresizes and the alignment behavior of the pores can potentially be used for theultrafiltration purposes as one of these applications. We demonstrated asuccessful separation of protein molecules and solid nanoparticles from aqueousmedia using polymeric films templated from LC media, the mass transferperformance of which was also dependent on the alignment direction of the poreswith respect to the surfaces. For the synthesized polymeric materials, we usedcharacterization methods such as thermal, optical, mechanical, nitrogenadsorption porosimetry and electron microscopy. Overall, the outcomes of thisstudy provide basic tools for the synthesis of porous polymeric films withpredetermined pore directions that can potentially be suitable for separationpurposes, drug delivery, catalysts, etc.


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Karausta, Asli; Büküşoğlu, Emre (American Chemical Society (ACS), 2018-10-03)
We demonstrate that polymeric films templated from liquid crystals (LCs) provide basic design principles for the synthesis of mesoporous films with predetermined pore alignment. Specifically, we used LC mixtures of reactive [4-(3-acryloyoxypropyloxy) benzoic acid 2-methyl-1,4-phenylene ester (RM257)] and nonreactive [4-cyano-4'-pentylbiphenyl (5CB)] mesogens confined in film geometries. The LC alignment was maintained by functionalization of the surfaces contacting the films during polymerization. Through p...
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Citation Formats
A. Karausta and E. Büküşoğlu, “Liquid Crystal-Templated Synthesis of Anisotropic Ultrafiltration Membranes,” 2018, Accessed: 00, 2021. [Online]. Available: