scholarly journals Organically Modified Nanoclay Filled Thin-Film Nanocomposite Membranes for Reverse Osmosis Application

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3803 ◽  
Author(s):  
Syed Zaidi ◽  
Farid Fadhillah ◽  
Haleema Saleem ◽  
Alaa Hawari ◽  
Abdelbaki Benamor

This study validates, for the first time, the effectiveness of two nanoclays, that is, cloisite (CS)-15A and montmorillonite (MNT) at the polyamide (PA) active layer in the reverse osmosis (RO) membrane. Cloisite-15A is natural montmorillonite modified with dimethyl dihydrogenated tallow quaternary ammonium salt. Thin-film composite (TFC) membranes were fabricated by the interfacial polymerization (IP) process between the trimesoylchloride (TMC)–n-hexane solution and m-phenylenediamine (MPD)–aqueous solution; the IP process took place on a polysulfone support sheet. The two types of nanoparticles were added in various weight ratios (0.005 wt.%–0.04 wt.%) in the n-hexane solution of TMC. Different characterizations like X-ray diffraction (XRD), contact angle, transmission electron microscopy (TEM), and membrane performance tests were performed to analyse the membrane properties. Both XRD and TEM studies proved that the two nanoclays are successfully anchored at the different sites of the PA layer. CS-15A could accelerate the water flux from 15 to 18.65 L/m2·h with NaCl rejection enhancement from 72% to 80%, relative to the control membrane. Conversely, MNT also enhanced the flux from 15 to 40 L/m2·h, but NaCl rejection reduced from 70% to 23%. The mechanism of water uptake in nanoclays was also discussed. The results pave the way for a complete future study, in which these phenomena should be studied in great detail.

2020 ◽  
pp. 82-90
Author(s):  
Ehsan Kianfar ◽  
H. Mazaheri

In this study, the synthesized is nanocomposite (CAU-10-H) all samples were characterized by Scanning electron microscope (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The (nanofiltration (NF)) membranes were constructed by interfacial polymerization of 1, 3, 5-benzenetricarbonyl trichloride and Piperazine using different loading of (CAU-10-H) (0.250, 0.50% wt.). The removal of color from the water by membranes with Solution filtration showed that the membrane containing 0.50% wt. of the nanocomposite (CAU-10-H) had the best. The removal of color from the water flux rejection of the thin-film nanocomposite (TFN) membrane which the removal of color from the water flux was 25.45 L/m2.hr and Tirmethylcyclohexan-1-one rejection was 99.35% at 6 bar.


2019 ◽  
Vol 258 ◽  
pp. 04003
Author(s):  
Azman Ismail ◽  
Ramlah Mohd Tajuddin ◽  
Hamizah Mohktar ◽  
Ahmad Fauzi Ismail

A modified thin film PSf-MCC reverse osmosis membrane was prepared by interfacial polymerization between aqueous MPD and TMC as the organic monomer. Aim of this study is to determine the effect of MCC in membrane formulation and fabrication. The surface and cross section morphology of TFC PSF/MCC membrane shows MCC particle which able to improve hydrophilicity of the membrane. The SEM images showed dense and porous structure of the MCC incorporated membranes. In addition, the water contact angle measurement also confirmed the increased hydrophilicity of the modified membranes. The effect of MCC on membrane matric influence the membrane performance in terms of NaCl rejection and pure water flux. Results showed that TFC PSf/MCC membrane shows NaCl rejection up to 98.9% compared with TFC PSf membrane. TFC PSf/MCC membrane also showed the highest pure water flux which is 3.712 Lm2/hr compare with TFC PSF membrane which is 3.606 Lm2/hr. The overall result proved that MCC particle could improve membrane hydrophilicity hence, increased pure water flux and salt rejection.


2019 ◽  
Vol 69 (2) ◽  
pp. 122-133 ◽  
Author(s):  
Juan Xiong ◽  
Yexia Gong ◽  
Cong Ma ◽  
Xingtao Zuo ◽  
Jiajie He

Abstract The hydrophilic and antimicrobial polyvinylidene fluoride (PVDF) membrane was fabricated by phase inversion method. The prepared membranes with various concentrations of ZnO nanoparticles (NPs) were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and membrane properties were investigated in terms of hydrophilicity, water flux, BSA solution filtration experiments, etc. Antibacterial testing was also performed to examine the practicability of the PVDF-ZnO membranes in overcoming biofouling. The results of FTIR and XRD confirmed the presence of ZnO NPs in the polymer matrix. The membrane performance demonstrated the significance of hydrophilic nanoparticles towards the enhancement of membrane properties. The optimum amount of ZnO NPs was 1.5 wt% with a lower contact angle as well as highest flux and lowest filtration resistance. The presence of ZnO NPs in the membrane matrix exhibited a strong antibacterial activity increased with the increasing ZnO NPs' content. Incorporation of ZnO NPs into PVDF membranes may have great potential in developing high-performance antifouling membranes for separation process.


Membranes ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 66 ◽  
Author(s):  
Ahmed Al Mayyahi

In this study, TiO2 nanoparticles were inserted into the polyamide layer of traditional thin film composite membrane. The nanoparticles were dispersed in a trimesoyl chloride-hexane solution before interfacial polymerization with m-phenylenediamine-aqueous solution. Membrane characterization was performed via contact angle measurements, atomic force microscopy (AFM), scanning electron microscopy (SEM), and water flux, salt rejection, and fouling resistance evaluation. The results indicate that TiO2 could effectively improve membrane performance. Water flux increased from 40 to 65 L/m² h by increasing NPs concentration from 0 to 0.1 wt. %, while NaCl rejection was above 96%. Moreover, the modified membrane demonstrated better organic fouling resistance and robust antibacterial efficiency.


Author(s):  
Haleema Saleem ◽  
Syed Javaid Zaidi

Reverse osmosis (RO) is considered as the most widely utilized technique worldwide for water treatment. However, the commercial thin-film composite (TFC) membranes, which are normally made of polyamide (PA) through interfacial polymerization (IP), still experience certain major issues in performance and fabrication. The spin assisted layer-by-layer (SA-LbL) technique was established for overcoming some drawbacks with commercially available PA membranes. Also, recent investigations have recognized the nanoparticle inclusion into the selective layer as a powerful technique for improving the membrane efficiency. Hence, two different methodologies are presented here to improve the membrane performance, i.e., (1) SA-LbL technique to fabricate TFC membrane by the deposition of alternate ultrathin layers of different polyelectrolytes on polysulfone (PSF) commercial ultrafiltration membrane and (2) the nanoclay incorporation into the membranes during IP process to develop TFC membrane. Two types of nanoclays, cloisite (CS)-15A and montmorillonite (MNT), were incorporated to enhance the separation efficiency. This SA-LbL is an innovative method for the RO membrane manufacture, and has not been described earlier to the best of our knowledge. In addition, this work validated for the first time, the efficiency of the two nanoclays at the PA selective layer in the RO membrane. The membrane performance was evaluated using sodium chloride solution in a cross-flow permeation-testing cell for salt rejection and water flux. The results show significant improvement in water flux and salt rejection. The permeation test of 120 bilayers of poly (allylaminehydrochloride)/poly (vinylsulfate) on PSF substrate showed water flux of 37 L/ (m2.h) and salt rejection of 53%, for a 2000-ppm salt solution feed. The highest water flux of 40 L/m2.h with 80% salt rejection, relative to the control membrane was obtained for the membranes containing nanoclays at 25oC temperature, 40.0 bar pressure and 2000 ppm feed concentration. Thus, our study demonstrated that these TFC membranes are promising, and these novel fabrication techniques are great tool to manufacture the RO membrane.


2003 ◽  
Vol 775 ◽  
Author(s):  
Donghai Wang ◽  
David T. Johnson ◽  
Byron F. McCaughey ◽  
J. Eric Hampsey ◽  
Jibao He ◽  
...  

AbstractPalladium nanowires have been electrodeposited into mesoporous silica thin film templates. Palladium continually grows and fills silica mesopores starting from a bottom conductive substrate, providing a ready and efficient route to fabricate a macroscopic palladium nanowire thin films for potentially use in fuel cells, electrodes, sensors, and other applications. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicate it is possible to create different nanowire morphology such as bundles and swirling mesostructure based on the template pore structure.


Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Celia Marcos ◽  
María de Uribe-Zorita ◽  
Pedro Álvarez-Lloret ◽  
Alaa Adawy ◽  
Patricia Fernández ◽  
...  

Chert samples from different coastal and inland outcrops in the Eastern Asturias (Spain) were mineralogically investigated for the first time for archaeological purposes. X-ray diffraction, X-ray fluorescence, transmission electron microscopy, infrared and Raman spectroscopy and total organic carbon techniques were used. The low content of moganite, since its detection by X-ray diffraction is practically imperceptible, and the crystallite size (over 1000 Å) of the quartz in these cherts would be indicative of its maturity and could potentially be used for dating chert-tools recovered from archaeological sites. Also, this information can constitute essential data to differentiate the cherts and compare them with those used in archaeological tools. However, neither composition nor crystallite size would allow distinguishing between coastal and inland chert outcrops belonging to the same geological formations.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2623
Author(s):  
Monika Wójcik-Bania ◽  
Jakub Matusik

Polymer–clay mineral composites are an important class of materials with various applications in the industry. Despite interesting properties of polysiloxanes, such matrices were rarely used in combination with clay minerals. Thus, for the first time, a systematic study was designed to investigate the cross-linking efficiency of polysiloxane networks in the presence of 2 wt % of organo-montmorillonite. Montmorillonite (Mt) was intercalated with six quaternary ammonium salts of the cation structure [(CH3)2R’NR]+, where R = C12, C14, C16, and R’ = methyl or benzyl substituent. The intercalation efficiency was examined by X-ray diffraction, CHN elemental analysis, and Fourier transform infrared (FTIR) spectroscopy. Textural studies have shown that the application of freezing in liquid nitrogen and freeze-drying after the intercalation increases the specific surface area and the total pore volume of organo-Mt. The polymer matrix was a poly(methylhydrosiloxane) cross-linked with two linear vinylsiloxanes of different siloxane chain lengths between end functional groups. X-ray diffraction and transmission electron microscopy studies have shown that the increase in d-spacing of organo-Mt and the benzyl substituent influence the degree of nanofillers’ exfoliation in the nanocomposites. The increase in the degree of organo-Mt exfoliation reduces the efficiency of hydrosilylation reaction monitored by FTIR. This was due to physical hindrance induced by exfoliated Mt particles.


2017 ◽  
Vol 527 ◽  
pp. 121-128 ◽  
Author(s):  
Wansuk Choi ◽  
Sungkwon Jeon ◽  
Soon Jin Kwon ◽  
Hosik Park ◽  
You-In Park ◽  
...  

1999 ◽  
Vol 14 (4) ◽  
pp. 1190-1193 ◽  
Author(s):  
J. H. Kim ◽  
A. T. Chien ◽  
F. F. Lange ◽  
L. Wills

Epitaxial PbZr0.5Ti0.5O3 (PZT) thin films were grown on top of a SrRuO3 epitaxial electrode layer on a (100) SrTiO3 substrate by the chemical solution deposition method at 600 °C. The microstructure of the PZT thin film was investigated by x-ray diffraction and transmission electron microscopy, and the ferroelectric properties were measured using the Ag/PZT/SRO capacitor structure. The PZT thin film has the epitaxial orientational relationship of (001) [010]PZT ║ (001) [010]SRO ║ (001) [010]STO with the substrate. The remnant (Pr ) and saturation polarization (Ps) density were measured to be Pr ~ 51.4 µC/cm2 and Ps ~ 62.1 µC/cm2 at 5 V, respectively. Ferroelectric fatigue measurements show that the net-switching polarization begins to drop (to 98% of its initial value) after 7 × 108 cycles.


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