Industrial & Engineering Chemistry Research, Год журнала: 2023, Номер 62(46), С. 19813 - 19821

Опубликована: Ноя. 8, 2023

Polyamide structure and chemistry play critical roles in the separation performance of thin-film composite (TFC) nanofiltration (NF) membranes. Typically, polyamide formation is based on reactive sites monomers (e.g., amino groups piperazine (PIP)) during interfacial polymerization (IP). To precisely tailor properties cross-linking degree) membrane performance, we regulated PIP by pH adjustment to vary dominant species forms non-, mono-, diprotonated PIP. Specifically, at values between pKa1 (i.e., 5.3) pKa2 9.7), monoprotonated with relatively fewer nonprotonated resulted a reduced degree polyamide. Such cross-linked exhibited simultaneously improved water permeance better solute-to-solute selectivity CaCl2/Na2SO4 CaCl2/PFOS selectivity), thanks their looser more negative charge. For example, NF-pH9, prepared 9, (20.2 L m–2 h–1 bar–1) higher (12.6). The little nonprotonation < ineffective low salt rejection 0.9 ± 0.3% Na2SO4). This study investigated facile strategy regulating monomer sites, which provides new insights into development high-performance NF

Язык: Английский