کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
634545 | 1456070 | 2013 | 10 صفحه PDF | دانلود رایگان |
The synthesis of polyamide films used as active layers in reverse osmosis membranes was studied by in-situ diffuse reflectance spectroscopy, Rutherford backscattering spectrometry (RBS), and atomic force microscopy (AFM). Aromatic polyamide layers were formed by interfacial polymerization on porous polysulfone supports using varying concentrations of m-phenylenediamine (MPD) in water of 0.1–100 g/L with a fixed concentration of trimesoyl chloride (TMC) in hexane of 1 g/L and varying TMC concentrations of 0.1–10 g/L with a fixed MPD concentration of 20 g/L. Polyamide growth dynamics were monitored in real-time by diffuse optical reflectance at λ=329 nm. A relationship was developed between diffuse reflectance and polyamide thickness. The diffuse reflectance data show that ∼50% of the polyamide thickness is produced in <2 s for all TMC concentrations studied and for MPD concentrations >2 g/L. All studied concentrations of TMC at a fixed 20 g/L MPD concentration produced a polyamide thickness of ≈120 nm. Polyamide thickness increased from ≈10 to 110 nm with increasing concentration of MPD at 1 g/L TMC. The roughness measured by AFM increased with increasing MPD concentration but decreased with increasing TMC concentration. At MPD concentrations <0.5 g/L, polyamide does not grow on top of the polysulfone.
► Study of growth dynamics and morphology of polyamide reverse osmosis active layers.
► >50% of the polyamide thickness was produced in the first 10 s of polymerization.
► Thickness increased with increasing MPD and was ≈120 nm for all TMC concentrations.
► Roughness increased with increasing MPD and decreased with increasing TMC.
► At MPD concentrations <0.5 g/L, polyamide grows within the polysulfone pores.
Journal: Journal of Membrane Science - Volume 429, 15 February 2013, Pages 71–80