*2.1. Materials*

All of the solvents and chemicals used were of analytical grade and were used without further purification. Zinc sulfate (ZnSO4·7H2O), sodium sulphide (Na2S·9H2O), manganese chloride (MnCl2·4H2O), ferric chloride crystal (FeCl3·6H2O), anhydrous sodium acetate (NaAc) and trisodium citrate dihydrate (Na3Cit·2H2O) were purchased from Beijing Chemical Works (Beijing, China). Bisphenol A, 4,4-bisphenol (BP) and ethylene glycol (EG) were obtained from Sinopharm Chemical Reagent Co. Ltd. (Beijing, China). 1.1-Bis (4-hydroxyphenyl) cyclohexane (BPZ) was received from Tokyo Chemical Industry Co. Ltd. (Tokyo, Japan). Mercaptoethylamine (MEA), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), *N*-hydroxysuccinimide (NHS) were purchased from Macklin Biochemical Co. Ltd. (Shanghai, China). Tetraethyl silicate (TEOS), 4-tert-butylphenol (PTBP), 3-aminopropyltriethoxylsilane (APTES) were purchased from Beijing J&K Chemical Technology Co. Ltd. (Beijing, China). All solutions were prepared with double deionized water (DDW).
