Antibiofouling Performance by Polyethersulfone Membranes Cast with Oxidized Multiwalled Carbon Nanotubes and Arabic Gum

Despite extensive research efforts focusing on tackling membrane biofouling, one of the biggest problems associated with membrane technology, there has been little headway in this area. This study presents novel polyethersulfone (PES) membranes synthesized via a phase inversion method at incremental loadings of functionalized oxidized multiwalled carbon nanotubes (OMWCNT) along with 1 wt. % arabic gum (AG). The synthesized OMWCNT were examined using scanning electron microscopy and transmission electron microscopy for morphological changes compared to the commercially obtained carbon nanotubes. Additionally energy-dispersive X-ray spectroscopy was carried out on the raw and OMWCNT materials, indicating an almost 2-fold increase in oxygen content in the latter sample. The cast PES/OMWCNT membranes were extensively characterized, and underwent a series of performance testing using bovine serum albumin solution for fouling tests and model Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial species for anti-biofouling experiments. Results indicated that the composite PES membranes, which incorporated the OMWCNT and AG, possessed significantly stronger hydrophilicity and negative surface charge as evidenced by water contact angle and zeta potential data, respectively, when compared to plain PES membranes. Furthermore atomic force microscopy analysis showed that the PES/OMWCNT membranes exhibited significantly lower surface roughness values. Together, these membrane surface features were held responsible for the anti-adhesive nature of the hybrid membranes seen during biofouling tests. Importantly, the prepared membranes were able to inhibit bacterial colonization upon incubation with both Gram-positive and Gram-negative bacterial suspensions. The PES/OMWCNT membranes also presented more resilient normalized flux values when compared to neat PES and commercial membrane samples during filtration of both bacterial suspensions and real treated sewage effluents. Taken together, the results of this study allude to OMWCNT and AG as promising additives, for incorporation into polymeric membranes to enhance biofouling resistance.

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Enhanced Fouling Resistance and Antibacterial Properties of Novel Graphene Oxide-Arabic Gum Polyethersulfone Membranes

Applied Sciences ◽

10.3390/app9030513 ◽

2019 ◽

Vol 9 (3) ◽

pp. 513 ◽

Cited By ~ 9

Author(s):

Ahmad Najjar ◽

Souhir Sabri ◽

Rashad Al-Gaashani ◽

Viktor Kochkodan ◽

Muataz Atieh

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Surface Charge ◽

Pore Size ◽

Bacterial Species ◽

Inversion Method ◽

Gram Positive ◽

Arabic Gum ◽

Gram Negative ◽

Morphological Studies

Membrane biofouling has proved to be a major obstacle when it comes to membrane efficiency in membrane-based water treatment. Solutions to this problem remain elusive. This study presents novel polyethersulfone (PES) membranes that are fabricated using the phase inversion method at different loadings of graphene oxide (GO) and 1 wt. % arabic gum (AG) as nanofiller and pore forming agents. Synthesized GO was examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for morphological studies and energy-dispersive X-ray spectroscopy (EDX) for elemental analysis. The prepared GO flakes showed a high content of oxygen-containing groups (~31%). The fabricated membranes were extensively characterized, including water contact angle analysis for hydrophilicity, zeta potential measurements for surface charge, SEM, total porosity and pore size measurements. The prepared membranes underwent fouling tests using bovine serum albumin (BSA) solutions and biofouling tests using model Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial suspensions as well as real treated sewage effluent (TSE). The results showed that the novel PES/GO membranes possessed strong hydrophilicity and negative surface charge with an increase in porosity, pore size and water flux. The PES/GO membranes exhibited superior antibacterial action against both Gram-positive and Gram-negative bacterial species, implicating PES membranes which incorporate GO and AG as novel membranes that are capable of high antibiofouling properties with high flux.

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SILK FIBROIN FILMS CRYSTALLIZED BY MULTIWALLED CARBON NANOTUBES

International Journal of Modern Physics B ◽

10.1142/s0217979208047456 ◽

2008 ◽

Vol 22 (09n11) ◽

pp. 1807-1812 ◽

Cited By ~ 4

Author(s):

H.-S. KIM ◽

W.-I. PARK ◽

Y. KIM ◽

H.-J. JIN

Keyword(s):

Electron Microscopy ◽

Carbon Nanotubes ◽

Multiwalled Carbon Nanotubes ◽

Silk Fibroin ◽

Composite Films ◽

Tensile Modulus ◽

Multiwalled Carbon ◽

Regenerated Silk Fibroin ◽

Silk Films ◽

Β Sheet

Silk films prepared from regenerated silk fibroin are normally stabilized by β-sheet formation through the use of solvents (methanol, water etc.). Herein, we report a new method of preparing water-stable films without a β-sheet conformation from regenerated silk fibroin solutions by incorporating a small amount (0.2 wt%) of multiwalled carbon nanotubes (MWCNTs). To extend the biomaterial utility of silk proteins, forming water-stable silk-based materials with enhanced mechanical properties is essential. Scanning electron microscopy and transmission electron microscopy were used to observe the morphology of the MWCNT-incorporated silk films. The wide-angle X-ray diffraction provided clear evidence of the crystallization of the silk fibroin induced by MWCNT in the composite films without any additional annealing processing. The tensile modulus and strength of the composite films were improved by 108% and 51%, respectively, by the incorporation of 0.2 wt% of MWCNTs, as compared with those of the pure silk films. The method described in this study will provide an alternative means of crystallizing silk fibroin films without using an organic solvent or blending with any other polymers, which may be important in biomedical applications.

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Surface Properties of Silica–MWCNTs/PDMS Composite Coatings Deposited on Plasma Activated Glass Supports

Applied Sciences ◽

10.3390/app11199256 ◽

2021 ◽

Vol 11 (19) ◽

pp. 9256

Author(s):

Michał Chodkowski ◽

Iryna Ya. Sulym ◽

Konrad Terpiłowski ◽

Dariusz Sternik

Keyword(s):

Electron Microscopy ◽

Carbon Nanotubes ◽

Scanning Electron Microscopy ◽

Multiwalled Carbon Nanotubes ◽

Composite Coatings ◽

Thermal Analyses ◽

Sol Gel ◽

Visible Range ◽

Multiwalled Carbon ◽

Scanning Electron

In this paper, we focus on fabrication and physicochemical properties investigations of silica–multiwalled carbon nanotubes/poly(dimethylsiloxane) composite coatings deposited on the glass supports activated by cold plasma. Air or argon was used as the carrier gas in the plasma process. Multiwalled carbon nanotubes were modified with poly(dimethylsiloxane) in order to impart their hydrophobicity. The silica–multiwalled carbon nanotubes/poly(dimethylsiloxane) nanocomposite was synthesized using the sol–gel technique with acid-assisted tetraethyl orthosilicate hydrolysis. The stability and the zeta potential of the obtained suspension were evaluated. Then, the product was dried and used as a filler in another sol–gel process, which led to the coating application via the dip-coating method. The substrates were exposed to the hexamethyldisilazane vapors in order to improve their hydrophobicity. The obtained surfaces were characterized by the wettability measurements and surface free energy determination as well as optical profilometry, scanning electron microscopy, and transmittance measurements. In addition, the thermal analyses of the carbon nanotubes as well as coatings were made. It was found that rough and hydrophobic coatings were obtained with a high transmittance in the visible range. They are characterized by the water contact angle larger than 90 degrees and the transmission at the level of 95%. The X-ray diffraction studies as well as scanning electron microscopy images confirmed the chemical and structural compositions of the coatings. They are thermally stable at the temperature up to 250 °C. Moreover, the thermal analysis showed that the obtained composite material has greater thermal resistance than the pure nanotubes.

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Determination of aniline derivatives in water samples after preconcentration with oxidized multiwalled carbon nanotubes as solid-phase extraction disk

Frontiers of Chemical Science and Engineering ◽

10.1007/s11705-012-1298-x ◽

2012 ◽

Vol 6 (3) ◽

pp. 270-275 ◽

Cited By ~ 1

Author(s):

Hideyuki Katsumata ◽

Yuta Oda ◽

Satoshi Kaneco ◽

Tohru Suzuki ◽

Kiyohisa Ohta

Keyword(s):

Carbon Nanotubes ◽

Solid Phase Extraction ◽

Multiwalled Carbon Nanotubes ◽

Water Samples ◽

Solid Phase ◽

Phase Extraction ◽

Multiwalled Carbon ◽

Oxidized Multiwalled Carbon Nanotubes ◽

As Solid Phase

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Covalent functionalization of multiwalled carbon nanotubes with super-hydrophobic property

Journal of Polymer Engineering ◽

10.1515/polyeng-2017-0096 ◽

2018 ◽

Vol 38 (6) ◽

pp. 537-543 ◽

Cited By ~ 1

Author(s):

Minghua Li ◽

Zhiyuan Xu ◽

Jinyang Chen ◽

San-E Zhu

Keyword(s):

Electron Microscopy ◽

Carbon Nanotubes ◽

Multiwalled Carbon Nanotubes ◽

Chemical Interaction ◽

Hydrophobic Property ◽

Covalent Functionalization ◽

Multiwalled Carbon ◽

Surface Contact Angle ◽

Loading Ratio ◽

Functionalized Mwcnts

AbstractSurface covalent functionalization of multiwalled carbon nanotubes (MWCNTs) is carried out by coupling of isocyanate-decorated MWCNTs with hydroxyl-terminated polydimethylsiloxane (HTPS), resulting in the formation of functionalized MWCNTs. Thermogravimetry analysis (TGA) of functionalized MWCNTs-1,2,3 exhibits the similar peaks in the temperature range of 200–500°C, which all correspond to the degradation of chemically grafted polyurethane on the nanotube surface. Field emission scanning electron microscopy (FE-SEM) reveals that as the polyurethane grafted onto the surface of MWCNTs loading ratio increased, the surface roughness of the MWCNTs is reduced. The chemical interaction of HTPS with isocyanate-decorated nanotube surface using the grafting-to strategy in a one-step process is confirmed by Fourier transform infrared spectroscopy (FT-IR). The surface contact angle of MWCNTs-3 with the largest content of polyurethane reached 171°, indicating that the surface covered with low surface energy polyurethane shows a super-hydrophobic property. The good dispersion of polyurethane-functionalized MWCNT-3, particularly at high content in the NR nanocomposites, is evidenced from transmission electron microscopy (TEM).

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