Supporting Information

Transcription

1 Supporting Information Mussel-inspired Architecture of High-flux Loose Nanofiltration Membrane Functionalized with Antibacterial Reduced Graphene Oxide-copper Nanocomposites Junyong Zhu, a Jing Wang, a, b Adam Andrew Uliana, c, d Miaomiao Tian, a Yiming Zhang, b Yatao Zhang, b* Alexander Volodin, e Kenneth Simoens, a Shushan Yuan, a Jian Li, a Jiuyang Lin, f Kristel Bernaerts, a a, g* Bart Van der Bruggen a Department of Chemical Engineering, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium b School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou , China c Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA d Department of Chemical and Biomolecular Engineering, The University of California, Berkeley, California 94720, USA e Laboratory of Solid-State Physics and Magnetism, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium f School of Environment and Resources, Qi Shan Campus, Fuzhou University, No. 2 Xueyuan Road, University Town, Fuzhou, Fujian, China g Faculty of Engineering and the Built Environment, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa *Corresponding authors: Yatao Zhang, zhangyatao@zzu.edu.cn Bart Van der Bruggen, bart.vanderbruggen@kuleuven.be S-1

2 List of Tables: 1. Characterizations of direct and reactive dyes used in this study. 2. Zeta potential of HPAN, PDA, PDA-GO2, PDA-rGOC2, and PDA-rGOC3 membranes. List of Figures: 1. (a) SEM images of rgoc nanocomposites; (b) EDS elemental analysis of rgoc nanocomposites. 2. XRD patterns for GO nanosheets (inset) and rgo-cu composites. 3. AFM images of GO sheets (a) and rgo-cu composites (c), and line scans taken along the line of AFM images of GO (b), and rgo-cu (d). 4. Cross-sectional SEM images of PDA-modified membranes (a), PDA-rGOC1 (b), PDA-rGOC2 (c), and PDA-rGOC3 membranes (d). 5. Pore size distribution and molecular weight cut-off (MWCO) of PDA, PDA-GO2, PDA-rGOC2, and PDA-rGOC3 membranes. 6. Long-term stability of PDA-rGOC3 membranes (operating conditions: 4 bar, 500 mg/l DR23) S-2

3 List of Tables Table S1 Characterizations of direct and reactive dyes used in this study. Dye MW a (g mol -1 ) Chemical structure λ max b (nm) Direct red 23 (DR 23) Congo red (CR) Reactive blue 2 (RB 2) Notes: a molecular weight, b maximum absorption wavelength. Table S2 Zeta potential of HPAN, PDA, PDA-GO2, PDA-rGOC2, and PDA-rGOC3 membranes. Membrane HPAN PDA PDA-GO2 Zeta potential (mv) PDA-rGOC 2 PDA-rGOC -33.5± ± ± ± ±0.4 3 S-3

4 List of Figures: Figure S1. (a) SEM images of rgoc nanocomposites; (b) EDS elemental analysis of rgoc nanocomposites. Figure S2. XRD patterns for GO nanosheets (inset) and rgo-cu composites. S-4

5 Figure S3. AFM images of GO sheets (a) and rgo-cu composites (c), and line scans taken along the line of AFM images of GO (b), and rgo-cu (d). Figure S4. Cross-sectional SEM images of PDA-modified membranes (a), PDA-rGOC1 (b), PDA-rGOC2 (c), and PDA-rGOC3 membranes (d). S-5

6 Figure S5. Pore size distribution and molecular weight cut-off (MWCO) of PDA, PDA-GO2, PDA-rGOC2, and PDA-rGOC3 membrane. The pore size, pore size distribution and molecular weight cut-off (MWCO) were measured based on the rejection of different molecular weight (600, 1500, 2000, 3000 Da) of polyethylene glycol (PEG, 200 mg L -1 ). The concentrations of permeate and feed solutions were measured by a TOC analyzer (Shimadzu TOC-VCPN, Japan). The Stokes radii of PEG was calculated based on their average Mw as follows: 1,2 The solute rejections against the Stokes radii were plotted and transformed it into a log-normal probability co-ordinate system. The MWCO, mean pore radius (µ p ), and geometric standard deviation (σ p ) of the membranes were estimated from the resultant linearized σ p function. µ p is defined as the geometric mean radius of solute at 50% solute rejection. σ p is defined as the ratio of the solute radius when solute rejections are 84.13% and 50%, and represents the geometric standard deviation of µ p. The pore size distributions of the membranes were described by the following probability density function. S-6

7 Figure S6 Long-term stability of PDA-rGOC3 membranes (operating conditions: 4 bar, 500 mg/l DR23) Reference: (1) Ong, Y. K.; Li, F. Y.; Sun, S.-P.; Zhao, B.-W.; Liang, C.-Z.; Chung, T.-S. Nanofiltration Hollow Fiber Membranes for Textile Wastewater Treatment: Lab-scale and Pilot-scale Studies. Chem. Eng. Sci. 2014, 114, (2) Lang, W.-Z.; Shen, J.-P.; Wei, Y.-T.; Wu, Q.-Y.; Wang, J.; Guo, Y.-J. Precipitation Kinetics, Morphologies, and Properties of Poly(vinyl butyral) Hollow Fiber Ultrafiltration Membranes with Respect to Polyvinylpyrrolidone Molecular Weight. Chem. Eng. J. 2013, 225, S-7