Improved Process for Preparing MWNTs/Polyester Thin Film Nanocomposite Membranes

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Researchers in Shanghai, People's Republic of China, have developed an improved process for preparing MWNTs/polyester thin film nanocomposite membranes. This new process involves interfacial polymerization of trimesoyl chloride (TMC) and triethanolamine (TEOA) solution containing MWNTs, followed by immersing the support membrane into the organic phase. The improved process results in a thin film composite membrane that exhibits high permeability and excellent selectivity compared to conventional processes.

Key Takeaways:

  • The improved process involves interfacial polymerization of TMC and TEOA solution containing MWNTs, followed by immersing the support membrane into the organic phase.
  • The MWNTs were embedded throughout the polyester thin film layer, as shown in TEM images.
  • The MWNTs/polyester thin film nanocomposite membrane prepared via the improved process exhibited both high permeability and excellent selectivity compared to the thin film composite membrane without MWNTs and the MWNTs/polyester thin film nanocomposite membrane prepared via the conventional process.
  • The water permeability increased upon an increase of reaction time of TMC-saturated support membrane immersed into aqueous phase, reaching a maximum of 4.7 L/m^(2) h at 25 min.
  • The membrane rejection rate kept increasing with the reaction time.
  • The improved process resulted in a low degree of cross-linking thin layer with high amount of hydrophilic and negatively charged carboxyl groups.

Statistics:

  • Water permeability increased from 0 to 4.7 L/m^(2) h upon an increase of reaction time of TMC-saturated support membrane immersed into aqueous phase.
  • Reaction time of 25 min resulted in a maximum water permeability of 4.7 L/m^(2) h.
  • Membrane rejection rate increased with increasing reaction time.

Sources:

  • Wu, H.Q., et al. "MWNTs/Polyester Thin Film Nanocomposite Membrane: An Approach To Overcome the Trade-Off Effect between Permeability and Selectivity." Journal of Physical Chemistry C, vol. 114, no. 39, 2010, pp. 16395-16407.
  • B.B. Tang, Fudan University, Key Laboratory Molecular Engineering Polymers, Minist Education, Shanghai 200433, People's Republic of China.