We synthesized poly(4-vinylbenzyltributylammonium hexanesulfonate) (P[VBTBA][HS]), a poly(ionic liquid) that shows lower critical solution temperature (LCST), via the anion exchange reaction of poly(4-vinylbenzyltributylammonium chloride) (P[VBTBA][Cl]) with sodium hexanesulfonate in order to investigate its suitability as a draw solute for the forward osmosis (FO) process. P[VBTBA][Cl] was obtained by the free radical polymerization of (4-vinylbenzyltributylammonium chloride [VBTBA][Cl]) monomer acquired by the Menshutkin reaction. The FO performance and recovery properties of the synthesized materials were systematically investigated. For example, the LCST of P[VBTBA][HS] was observed to be ∼17 °C at 20 wt%, while no LCST was observed for [VBTBA][Cl] monomer and P[VBTBA][Cl] polymer before the anion exchange reaction, indicating that P[VBTBA][HS] can be recovered from the aqueous solution by heating it to above its LCST. Moreover, in an active layer facing the feed solution (AL-FS) system containing 20 wt% aqueous P[VBTBA][HS] solution at 15 °C, the water flux and reverse solute flux of P[VBTBA][HS] were found to be ∼5.85 L m⁻² h⁻¹ and 1.13 g m⁻² h⁻¹, respectively. Therefore, we studied the feasibility of using the poly(ionic liquid), a homopolymer having LCST characteristics, as a draw solute in the FO process.

We synthesized the zwitterionic homopolymer polysulfobetaine (PBET), which shows upper critical solution temperature (UCST) characteristics, via free radical polymerization in order to investigate its suitability as a draw solute for the forward osmosis (FO) process. The FO and recovery properties of PBET were systematically investigated. The UCST characteristics of the monomer sulfobetaine (BET) were not confirmed, while the UCST of PBET was confirmed to be approximately 40 °C. This result suggests that PBET can be easily recovered from aqueous solutions by cooling them to below the UCST. In an active layer facing feed solution (AL-FS) system containing 20 wt% PBET at a temperature of 50 °C, the water flux and reverse solute flux of PBET were found to be approximately 3.22 LMH and 0.36 gMH, respectively. Thus, we investigated the suitability of homopolymers having UCST characteristics as draw solutes for the FO process for the first time.

To investigate the alignment behavior of liquid crystal (LC) molecules, we synthesized a series of vanillin derivative-substituted polystyrene films (PVAN#, # = 20, 40, 60, 80, and 100), where # is the substitution ratio (%) of the vanillyl butyl ether (VAN) moiety as one of the bio-renewable vanillin derivatives. In general, a vertical LC alignment was observed in the LC cell fabricated using the polymer film having a higher molar content of VAN. Moreover, the surface energies of these polymer films were strongly related to the vertical LC alignment behavior. For example, a uniform vertical alignment was observed when the polar surface energy of the polymer was lower than approximately 2.05 mJ m⁻², induced by the nonpolar and long carbon groups in the plant-based vanillin moiety. The LC cell fabricated using PVAN100 had good electrooptical characteristics such as voltage holding ratio and residual direct-current voltage and stable alignment under extreme external conditions.

The study determined the effect of incorporating Momordica charantia leaf powder (MCLP) into corn-starch 3D food-printing ink as a functional ingredient. The effects of the particle size (75, 131, and 200 μm) and quantity of MCLP on 3D printing performance, structural, textural, and rheological properties of corn starch gel were evaluated with different concentrations (5, 10, and 15 % (w/w)) of corn starch. The viscoelastic properties of food inks were determined considering their behavior during extrusion and self-recovery after printing. Scanning electron microscope was used to characterize the microstructure. Based on the results, a high starch content (15 %) with 5 % MCLP was more favorable for 3D food printing. In addition, 3D printing performance, textural and rheological properties of formulated ink was mainly governed by the particle size of MCLP. The food ink with a 5 % mass fraction of 200 μm MCLP had the highest printing precision and the best masticatory properties.

We synthesized a series of plant-based and renewable, eugenol-modified polystyrene (PEUG#) (# = 20, 40, 60, 80, and 100, in which # is the molar content of the eugenol moiety in the side group). Eugenol is extracted from clove oil. We used polymer modification reactions to determine the liquid crystal (LC) orientation properties of the polymer films. In general, the LC cells fabricated using the polymer films with a higher molar content of eugenol side groups exhibited vertical LC orientation behavior. The vertical orientation behavior was well correlated with the surface energy value of the polymer films. The vertical LC orientation could be formed due to the low polar surface energy value on the polymer film generated by the nonpolar carbon group. Electro-optical performances (e.g., voltage holding ratio (VHR), residual DC voltage (R-DC), and thermal orientation stabilities) were good enough to be observed for LC cells using PEUG100 polymer as an eco-friendly LC orientation material.

We synthesized a series of plant-based capsaincin substituted polystyrene (PCAP#, # = 20, 40, 60, 80, and 100), where # is the molar content of the N-vanillylnonanamide moiety as one of the capsaicin derivatives, using polymer analogous reactions to investigate their liquid crystal (LC) alignment properties. In general, the LC cell fabricated using the polymer film having a higher molar content of N-vanillylnonanamide side groups showed vertical LC alignment behavior. The vertical alignment behavior was well correlated with the surface energy of these polymer films. For example, vertical alignment was observed when the surface energy values of the polymer were smaller than about 29.26 mJ m⁻² generated by the nonpolar, long carbon groups. Good electro-optical characteristics, such as voltage holding ratio (VHR) and residual DC voltage (R-DC), and aligning stabilities at 200 °C were observed for the LC cells fabricated using PCAP100 as an eco-friendly LC alignment layer based on renewable capsaicin resource containing polymer films.