Span 80

Microcrystalline cellulose, titanium oxide (TiO₂), iron (III) oxide (Fe₂O₃), chitosan (low molecular weight), κ-carrageenan, methyl orange (MO), and 1-ethyl-3-methylimidazolium acetate ([Emim][Ac]) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Span 80, Congo red (CR), methylene blue (MB), crystal violet (CV), rhodamine B (RB), ethanol, isopropanol, hexane, and high-performance liquid chromatography (HPLC) grade water were purchased from Samchun Pure Chemical Co., Ltd. (Gyeonggi-do, Republic of Korea). Multi-walled carbon nanotubes (CMP-310F) were obtained from Hanwha Nanotech Co., Ltd. Incheon, Republic of Korea). All other chemicals used in this study were of analytical grade and used without further purification.

Polyvinyl alcohol 1788 (PVA 1788, Mw = 84, 000–89, 000) were purchased from Aladdin, Ltd. (Shanghai, China), PVDF (Mw ≈ 1,000,000) were purchased from Arkema, Ltd. (Paris, France), PMMA (Mw ≈ 210,000) were purchased from Shunjie Plastic Technology Co., Ltd. (Dongguan, China), GO dispersion (1 mg mL⁻¹) were purchased from XFNANO Materials Technology Co., Ltd. (Nanjing, China), potassium dihydrogen phosphate (KH₂PO₄, Mw = 136.09 gmol⁻¹) were obtained from Aladdin, Ltd. (Shanghai, China), Span80 were purchased from Samchun Chemical Co., Ltd. (Seoul, Korea), hydrochloric acid (HCl, 37 wt% in H₂O, Mw ≈ 36.46 gmol⁻¹), ethanol (CH₃CH₂OH, Mw = 46.07 gmol⁻¹), n-hexane (C₆H₁₄, Mw = 86.18 gmol⁻¹), glutaraldehyde (GA, 50 wt% in H₂O, Mw = 100.11 gmol⁻¹), N, N-dimethylformamide (DMF, Mw = 73.09 gmol⁻¹) and acetone (C₃H₆O, Mw = 58.08 gmol⁻¹) were obtained from Sinopharm Chemical Reagent Co., Ltd. (Beijing, China). All the reagents are analytically pure, purchased from Aladdin, without any impurities and need no further purification.