Amphoteric Locust Bean Gum based Terpolymer/ Bentonite Composite Hydrogel: Preparation, Swelling and Dye Adsorption Studies. Sirajo Abubakar Zauro and Vishalakshi B* Department of Post-Graduate Studies and Research in Chemistry, Mangalore University, Mangalagangothri, 574199, Karnataka, India 1. INTRODUCTION SEM Dye adsorption studies The clay-polymer composite have been gaining increased attention by researchers due to the hybrid properties they exhibit [1]. The presence of coloured pollutant especially non-biodegradable, toxic and carcinogenic dye becomes a major threat to water bodies [2]. The removal of these pollutants from waste water by means of cheaper and eco-friendly techniques is a major challenge. Hence, the use of materials such as polymeric composite hydrogels became increasingly adapted for the removal of dyes from waste water [3-5]. Based on the available literature, the information on LBG based graft copolymers and clay composite were limited and no data was reported on the adsorption of Indigo Carmine (IC) dye by the LBG graft copolymers. Hence, it forms the basis of this research. Fig. 5: a. First order adsorption kinetics, b. Second order adsorption kinetics of IC dye on the composite gel Fig 3: SEM images of a) LBG , b) LBG-g-PDADMAC, c) LBG-g-Poly(DADMAC-co-AMPS) and d) LBG-g-Poly(DADMAC-co-AMPS)/BNT 2. Methodology The surface is fibrous-like d. Coarse and undulant surface b. Homogeneous c. Cotton-like irregular shape Stirred @ 60 0C DADMAC, AMPS BNT LBG LBG. Fig. 6: Freundlich isotherms model for, a. LBG-g-poly(DADMAC-co-AMPS), b. LBG-g-poly(DADMAC-co-AMPS)/BNT APS MBA, MW(350w) Table 1: Second order swelling kinetics data of the terpolymer composite gel Swelling studies LBG-g-poly(DADMAC-co-AMPS) LBG-g-poly(DADMAC-co-AMPS)/BNT pH Seq exp Seq cal. ks ×10-3 R2 1.2 5.70 5.88 9.96 0.999 5.95 6.37 4.09 0.995 7.0 7.09 7.35 7.50 16.52 18.87 8.29 0.994 9.0 7.16 7.63 4.49 0.997 8.42 8.77 5.02 0.998 = BNT = MBA = DADMAC = AMPS = LBG LBG-g-poly(DADMAC-co-AMPS) LBG-g-poly(DADMAC-co-AMPS)/BNT 3. Results Table 2: Adsorption kinetics data of IC dye on terpolymer composite gel Order LBG-g-poly(DADMAC-co-AMPS) LBG-g-poly(DADMAC-co-AMPS)/BNT qe exp qe cal. k1 R2 K1 1st 17.36 77.90 0.0046 0.970 11.99 -16.40 0.000 0.865 2nd 18.58 0.0012 0.999 12.35 0.0022 0.998 FTIR 3311--- OH str c. In addition to the peaks in (a and b) 2912--- C-H str 1163--- C-O str. 1537--- N-H bend. 1004--- C-O-H vib 1032--- S-O str. from SO3H 1474--- C-N str. 1050--- Si-O str. 1634--- C=O str. 621-----Si-O-Al bend. 3022--- C-N+ str. 467---- Si-O-Si str. Table 3: Adsorption isotherms data of IC dye on terpolymer composite gel Langmuir isotherm model Freundlich isotherm model qm KL RL R2 n kf LBG-g-poly(DADMAC-co-AMPS) 111.11 0.01 0.50-0.91 0.678 1.07 0.50 0.999 LBG-g-poly(DADMAC-co-AMPS)/BNT 10.31 0.14 0.06-0.41 0.961 1.98 1.71 Fig. 4: a.Swelling capacity at different pH, b. Second order swelling kinetics of the terpolymer composite gel under different pH. 4. Conclusion In this work terpolymer composite gel consisting of LBG, DADMAC, AMPS and BNT clay was made via microwave irradiation. The terpolymer without clay showed highest swelling at pH 7.0, and followed second order kinetics in all the pH conditions. The adsorption data of IC on the terpolymer showed maximum adsorption of 17.36mg/g of terpolymer composite without clay compared to 11.99 mg/g of the clay composite terpolymer. The adsorption isotherms were observed to fit best into Freundlich model. Fig.1: FTIR Spectra of a. LBG, b. LBG-g-PDADMAC, c. LBG-g-poly(DADMAC-co-AMPS) and d. LBG-g-poly(DADMAC-co-AMPS)/BNT TGA 5. References 1st step – 60-100 0C -------- 2% c. 1st step – 60-300 0C ---------19% 2nd step – 300 -320 0C -----70% 2nd step – 300 -350 0C------41% 3rd step – 560 0C -------------18% 3rd step – 350 -510 0C-------15% 4th step – 640 0C--------------15% b. 1st step – 150 0C -------------12% as char. 2nd step – 340 0C ------------ 58% 3rd step – 550 0C ---------------30% d. 1st step – 60-300 0C-----------19% 2nd step – 300 -350 0C -------41% 3rd step – 350 -510 0C--------15% 4th step 510– 630 0C ---------0% [1]. A. S. Malana, S. Ijaz, M. N. Ashiqm, Desalination, 263 (2010) 249-257 [2]. J. S. Karthika, B. Vishalakshi, Int. J. Biol. Macromol. 81 (2015) 544-655 [3]. P. Luo, Y. Zhao, B. Zhang, J. Liu, Y. Yang, J. Liu, Water res. 44 (2010) 1489–1497 [4]. R. Jiang, Y. Fu, H. Zhu, J. Yao, L. Xiao, J. Appl. Polym. Sci. 125 (2012) 540–549 [5]. S. K. Gupta, M. K. Nayunigari, R. Misra, F. A. Ansari, D. D. Dionysiou, A. Maity, F. Bux.nd. Eng. Chem. Res., 55 (2015) 13−20 6. Acknowledgement One of the authors SAZ thanks the Government of India for providing the scholarship under Indian Council for Cultural Relations (ICCR). Fig 2: TGA curves of a. LBG, b. LBG-g-PDADMAC, c. LBG-g-poly(DADMAC-co- AMPS) and d. LBG-g-poly(DADMAC-co-AMPS)/BNT *Correspondence: vishalakshi2009@yahoo.com 9th KSTA Annual Conference, 20th to 21st December, 2016 @ Christ University Bengaluru