Oil/water separation and functionality of smart carbon nanotube–titania nanotube composite (original) (raw)
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Titania Nanotubes for Separation Applications
TechConnect Briefs, 2013
We synthesized titania nanotubes arrays in the form of powders and membranes by a cheap, simple and easily scalable anodization method. The nanotubes powders can be compacted inside steel high-performance liquid chromatography (HPLC) columns, or sintered to produce filtration pellets. Furthermore, we were able to successfully functionalize both types of materials described above with ligands such as C18, as a proof of concept regarding possible application in custom tailored filtration needs. Preliminary water-oil filtration experiments show good promise for such applications.
Korean Journal of Chemical Engineering, 2020
With the advantages of one-dimensional hollow structure, high porosity and prominent mechanical strength, single-walled carbon nanotubes (SWCNTs) have been extensively utilized to improve conventional filtration membranes for oil/water separation. Their intrinsic hydrophobicity, however, adversely affects the anti-fouling performance of the SWCNT membrane. Herein, a super-hydrophilic and underwater super-oleophobic hierarchical modified membrane with enhanced permeability and anti-fouling property was fabricated using the vacuum-assisted filtration technique by synergistically assembling SWCNTs and titanium dioxide (TiO 2) nanoparticles on a cellulose acetate membrane. Highly dispersed SWCNTs were obtained by carboxylating treatment of agglomerate SWCNTs. The controlled stacking of SWCNTs fibers and a controllable amount of TiO 2 rendered a modified membrane with high porosity and hierarchical structure, leading to an ultrahigh water flux up to 4,777.07 L•m 2 •h 1 , and excellent separation performance with efficiency greater than 99.47%. Most importantly, the membrane exhibited excellent anti-fouling ability during ten cycles with the aid of the super-wetting property of TiO 2 nanoparticles. The results indicated that coating TiO 2 nanoparticles on SWCNTs modified the surface topography of the obtained SWCNT/TiO 2 membrane, which improved hydrophilicity, permeability and anti-fouling property, manifesting attractive potential applications in oil/water separation.
Impact of Carbon Nanotubes on the Polymeric Membrane for Oil – Water Separation
International Journal of NanoScience and Nanotechnology, 2019
In this research, the classical phase inversion method was used to produce the polysulfone (PSF) membrane by using three different solvents: N, N-dimethylformamide (DMF), chloroform (CHCL3) and tetrahydrofuran (THF). Furthermore, different concentrations of functionalized multi – walled carbon nanotubes (MWCNTs) were added to PSF membranes by the classical phase inversion method. MWCNTs were synthesized using chemical vapour deposition (C.V.D) then functionalized by acid treatment. The morphology and the structure of the membrane and MWCNTs were characterized by using the scanning electron microscope (SEM) and transmission electron microscope (TEM). The characterization of the functionalization of the MWCNTs was performed by using the Raman spectroscopy. It was found that the chemical, physical and mechanical properties of the polymeric membrane improve with the content in functionalized MWCNTs concentration in the polymeric membrane matrix. The membrane with the MWCNTS concentratio...
Water Supply
For the effective purification of emulsified oil contaminated waters advanced treatment methods have to be applied, such as membrane filtration, which is able to eliminate macro-, and even nanoscale oil droplets, however, membrane fouling is still a major problem, which prevents economic utilization. Therefore, fouling mitigation is one of the most important aspects in the field of membrane separation developments. In the present study, solely TiO2 and TiO2/carbon nanotubes (CNT) composite modified PVDF membranes were prepared and used to purify oil-in-water emulsions. Achievable fluxes, reversible and irreversible filtration resistances, fouling models, filtration efficiencies and photocatalytic activities were compared in case of different nanomaterial covered and unmodified PVDF membranes. Applying either solely TiO2 or solely CNT coating resulted in the significant reduction of total filtration resistance in both cases, but the combination of the two components (TiO2 with 1 wt% ...
Chemosphere, 2016
Oil removal from water is a highly important area due to the large production rate of emulsified oil in water, which is considered one of the major pollutants, having a negative effect on human health, environment and wildlife. In this study, we have reported the application of high quality carbon nanotube bundles produced by an injected vertical chemical vapor deposition (IV-CVD) reactor for oil removal. High quality, bundles, super hydrophobic, and high aspect ratio carbon nanotubes were produced. The average diameters of the produced CNTs ranged from 20 to 50 nm while their lengths ranged from 300 to 500 μm. Two types of CNTs namely, P-CNTs and C-CNTs, (Produced CNTs from the IV-CVD reactor and commercial CNTs) were used for oil removal from water. For the first time, thermogravimetric analysis (TGA) was conducted to measure maximum oil uptake using CNT and it was found that P-CNT can take oil up to 17 times their weight. The effect of adsorbent dosage, contact time, and agitatio...
Investigation of Carbon Nanotubes in Mixed Matrix Membranes for Gas Separation: A Review
ChemBioEng Reviews, 2016
Mixed matrix membranes (MMM) consist of a polymeric base with additive fillers. Zeolites, carbon molecular sieves, graphene and carbon nanotubes (CNTs) are most commonly used fillers in the development of MMMs. Among these materials, CNTs have been proposed recently for gas separation application due to their attractive properties. Although CNTs have excellent separation properties, preparation of CNT-MMMs is more complicated. To employ CNTs as effective reinforcement in the polymeric matrix, proper dispersion and suitable interfacial adhesion between the CNTs and the polymer matrix have to be guaranteed. In this paper, recent advances and developments on CNTs dispersion and alignment in the matrix were reviewed. Also, a critical comparison of various CNT functionalization methods and different functional groups are given. Applications of CNT-MMMs in gas separation are also reviewed.
Journal of environmental chemical engineering, 2017
<xps:span class="xps_Image">fx1 Highlights► MWCNTs/ magnetite/SiO2 were prepared using dip coating method. ► Application of MWCNTs/magnetite/SiO2 in oil/water separation. ► The amphoteric MMWCNTs /SiO2 have excellent affinity with oil-water separation. ► MMWCNTs /SiO2 could be reused several times up to 5 times. Abstract Multi-walled carbon nanotubes decorated with magnetite (MMWCNTs) were prepared then modified with silicon oxide (MMWCNTs/SiO2) and characterized using high-resolution transmission electron microscope (HRTEM), dynamic light scattering (DLS), thermal gravimetric analysis (TGA), Fourier transform infrared photometer (FTIR), and X-Ray diffraction techniques (XRD). A bench scale experimental setup was designed for the oil in water mixture separation of the prepared materials. Subsequently, individual and interaction effects of operational parameters, e.g., MMWCNTs and MMWCNTs/SiO2 doses, initial oil concentration, pH and water salinity were investigated and optimized using response surface methodology (RSM) and ANOVA analysis at α = 0.05. The results of experimental data were fitted with polynomial models developed using RSM, and the regression analysis with an R 2 value of ≈ 0.99 showed the goodness of fit for the experimental results with predicted values. The experimental results showed higher oil/water separation for MMWCNTs/SiO2 than MMWCNTsitself with a separation rate of 92.8% and 72.4%, respectively at 1 g/l of initial oil concentration. Compared with other approaches for fabricating oil-water materials, the asprepared MMWCNTs/SiO2 is a promising candidate for efficient oil-water separation even after 5 cycles. Keywords: Multiwall carbon nanotubes; magnetic nanocomposite; hydrocarbon separation; column studies; response surface optimization.
Preparation of titania covered multi-walled carbon nanotube thin films
Materials & Design, 2015
The aim of this work was to investigate the effects of relative humidity on the formation of titania layers on the surface of multi-walled carbon nanotubes under regulated conditions in a sealed system. Reactive precursor compounds such as titanium (IV) oxychloride hydrochloric acid and titanium (IV) bromide were used as precursor to cover the surface of multi-walled carbon nanotubes (MWCNTs) under solvent conditions. The mixtures of MWCNTs and titania compounds were not stirred or sonicated. The effect of relative humidity was influenced using the mixture of sulphuric acid and water in desiccators. As-prepared titan-dioxide (TiO 2 ) layers were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TG), X-ray diffraction (XRD) and Raman spectroscopy. Our results revealed that TiO 2 layers with different thicknesses can be obtained using this simple sealed system. These TiO 2 covered multi-walled carbon nanotube films can be ideal candidates for different kinds of applications (e.g. sensors, virus filtration or catalysts).
Membranes, 2017
Effect of the dispersion method employed during the synthesis of carbon nanotube (CNT)/polysulfone-infused composite membranes on the quality and separation performance of the membranes during oil–water mixture separation is demonstrated. Carbon nanotube/polysulfone composite membranes containing 5% CNT and pure polysulfone membrane (with 0% CNT) were synthesized using phase inversion. Three CNT dispersion methods referred to as Method 1 (M1), Method 2 (M2), and Method 3 (M3) were used to disperse the CNTs. Morphology and surface property of the synthesized membranes were checked with scanning electron microscopy (SEM) and Fourier-transform infrared (FTIR) spectroscopy, respectively. Separation performance of the membranes was evaluated by applying the membrane to the separation of oil–water emulsion using a cross-flow filtration setup. The functional groups obtained from the FTIR spectra for the membranes and the CNTs included carboxylic acid groups (O–H) and carbonyl group (C=O) w...