The interfacial polymerization (IP) of piperazine (PIP) and trimesoyl chloride (TMC) has been extensively utilized to synthesize the nanofiltration (NF) membrane. However, it is still a huge challenge to monitor the IP reaction, because of the fast reaction rate and the formed ultra-thin film. Herein, two effective strategies are applied to reduce the IP reaction rate: (1) the introduction of hydrophilic interlayers between the porous substrate and the formed polyamide layer; (2) the addition of macromolecular additives in the aqueous solution of PIP. As a result, in-situ FT-IR spectroscopy was firstly used to monitor the IP reaction of PIP/TMC reaction system, with hydrophilic interlayers or macromolecular additives. Moreover, we study the formed polyamide layer growth on the substrate, in a real-time manner. The in-situ FT-IR experimental results confirm that the IP reaction rates are effectively suppressed and the formed polyamide thickness reduces from 138±24 nm to 46±2 nm. Furthermore, the optimized NF membrane with excellent performance are consequently obtained, which include the boosted water permeation flux about 141~238 (L·m2·h/MPa) and superior salt rejection of Na2SO4 > 98.4%.
AbstractThe reaction of 1,3,5-triethynyl-1,3,5-trimethyl- 1,3,5-trisilacyclohexane with (dimethylamino)trimethylstannane afforded 1,3,5-tris[(trimethylstannyl)ethynyl]- 1,3,5-trimethyl-1,3,5-trisilacyclohexane with tin-functionalised ethynyl groups. The compound was characterized by single-crystal X-ray diffraction, elemental analysis, mass spectrometry, NMR and FT-IR spectroscopy.
A first high-pressure study on MOF α-Mg3(HCOO)6 probed by in situ vibrational spectroscopy revealed strongly contrasting host-dependent structural transitions and stabilities.
Monitoring the Interfacial Polymerization of Piperazine and Trimesoyl Chloride with Hydrophilic Interlayer or Macromolecular Additive by in-situ FT-IR Spectroscopy