Preparation and characterization of UZM-5/polyamide thin film nanocomposite membrane for dewaxing solvent recovery

• Published in: Journal of membrane science 2014-06, Vol.459, p.22-32
• Main Authors: Namvar-Mahboub, Mahdieh, Pakizeh, Majid, Davari, Susan
• Format: Article
• Language: English
• Subjects: Atomic force microscopy; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Membranes; Nanoparticles; Nanostructure; Organic solvent nanofiltration; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Polyamide; Polyamide resins; Polymerization; Scanning electron microscopy; Solvents; Thin film nanocomposite; Thin films; UZM-5 nanoparticles
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2014.02.014

Thin-film nanocomposite (TFN) membrane containing amino-functionalized UZM-5 nanoparticles was synthesized by interfacial polymerization on polyetherimide (PEI)/modified SiO2 asymmetric substrate tailored for organic solvent nanofiltration OSN process. m-Phenylenediamine (MPD) with trimesoyl chloride (TMC) was polymerized to prepare polyamide layer. UZM-5 nanoparticles (~73nm) were synthesized and then functionalized by aminopropylediethoxymethylsilane (APDEMS) and finally incorporated into polyamide (PA) selective layer at concentrations ranging from 0 to 0.2w/v%. The as-prepared TFN membranes were characterized by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and contact angle measurements. The performances of membranes were also evaluated through dewaxing solvents (MEK and toluene) recovery from lube oil. FESEM and SEM images clearly confirmed that the polyamide/UZM-5 nanocomposite top layer was formed on the support surface and its morphology was significantly affected by UZM-5 loading. Interaction between functional groups of modified UZM-5 nanoparticles and polyamide matrix was established by ATR-FTIR. AFM results revealed that in the range of 0–0.1w/v% zeolite loading, the surface roughness of TFN membranes decreased due to the change of polyamide structure while at 0.2w/v% of zeolite loading, an increase in surface roughness was observed. It also resulted in enhanced hydrophilicity of TFN membranes in the range of 0–0.1w/v% UZM-5 loading, proved by a decreased water contact angle. The permeation test results indicated that the existence of UZM-5 in the polyamide selective layer improved both oil rejection and permeate flux under optimal concentration (0.02% w/v of UZM-5). •A novel TFN membrane was developed by the IP method on PEI/modified SiO2 support for OSN.•UZM-5 modified by APDEMS was successfully incorporated into the PA selective layer.•Functionalized UZM-5 influenced the structure of the selective layer.•Effects of FFR and UZM-5 loading on the performance of TFN–OSN membranes were investigated.•The performance of TFN membrane was improved at optimal UZM-5 loading.