scholarly journals Preparation and Properties of Polyvinylidene Fluoride Nanocomposited Membranes based on Poly(N-Isopropylacrylamide) Modified Graphene Oxide Nanosheets

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 473 ◽  
Author(s):  
Xiangli Meng ◽  
Yuan Ji ◽  
Genhua Yu ◽  
Yujia Zhai
Keyword(s):  
Contact Angle ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Polyvinylidene Fluoride ◽  
Phase Inversion ◽  
Doping Amount ◽  
Water Contact ◽  
Modified Graphene Oxide ◽  
Modified Graphene ◽  
Scanning Electron

The nanomaterial of graphene oxide grafting poly (N-isopropylacrylamide) (GO-g-PNIPAAm) was synthesized and PVDF/GO-g-PNIPAAm blended membranes were fabricated by wet phase inversion. In this work, a hydrophilic nanomaterial GO-g-PNIPAAm with poly(N-isopropylacrylamide) (PNIPAAm) grafted on GO, was synthesized by the atom transfer radical polymerization (ATRP) method. The resulting nanomaterial was confirmed by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectrum, and X-ray photoelectron spectroscopy (XPS) analysis. The synthesized GO-g-PNIPAAm was incorporated with polyvinylidene fluoride (PVDF) via phase inversion, and investigated for its temperature sensitivity, porosity, contact angle, scanning electron microscopy, and permeate properties. The water contact angle measurements confirmed that GO-g-PNIPAAm nanomaterial-endowed PVDF membranes with better hydrophilicity and thermo-responsive properties compared with those of the pristine PVDF membranes. Bovine serum albumin (BSA) adsorption experiments suggested that excellent antifouling properties of membranes were acquired after adding GO-g-PNIPAAm. The modified membranes showed good performance when the doping amount of GO-g-PNIPAAm was 0.2 wt %.

scholarly journals Improvement of Dispersibility of Graphene Oxide by Surface Modification with Rare Earths

2022 ◽  
Author(s):  
Yong Li ◽  
Zhou Jiang ◽  
Haidong Yu ◽  
Xuebin Zhou ◽  
Peng Yi
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Photoelectron Spectroscopy ◽  
Energy Dispersive Spectrometer ◽  
X Ray ◽  
Modified Graphene Oxide ◽  
Modified Graphene ◽  
The Rare Earth

Abstract Rare earth-modified graphene oxide (RE-M-GO) materials were successfully prepared by infiltration and heating modifier method. The morphology and phase structure of RE-M-GO were characterized by scanning electron microscopy(SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive spectrometer(EDS). The changes of the chemical structure were indicated by Fourier transform infrared (FTIR). X-ray photoelectron spectroscopy(XPS) was used to study the chemical state of the surface elements of graphene oxide which showed that the rare earth elements were added to the graphene oxide functional groups through the coordination reaction. Additionally, the findings concluded that the effect of modification by Ce is more obvious than La elements and the RE-M-GO materials prepared by the heating modifier method had better dispersibility than infiltration. With activating effect, the rare earth elements grafting to graphene oxide will contribute to its combination with other materials.

Surface Modification of Polycarbonateurethane by Grafting Phosphorylcholine Glyceraldehydes for Improving Hemocompatibility

2012 ◽  
Vol 1403 ◽  
Author(s):  
Wei Gao ◽  
Yakai Feng ◽  
Jian Lu ◽  
Jintang Guo
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Polymer Surface ◽  
Xps Analysis ◽  
Poly Ethylene Glycol ◽  
Water Contact ◽  
X Ray ◽  
Poly Ethylene ◽  
Covalently Linked ◽  
Scanning Electron

ABSTRACTPhosphorylcholine glyceraldehyde (PCGA) was used as a phosphorylcholine (PC) group containing compound to graft onto the surface of polycarbonateurethane (PCU) film using 1,6-hexanediamine (HDA) or α,ω-diamino-poly(ethylene glycol) (APEG, Mn = 200) as a spacer, in order to introduce biomimetic structure onto the polymer surface. X-ray photoelectron spectroscopy (XPS) analysis shows that PCGA has been covalently linked to the PCU surface. Water contact angle test suggests that the surface hydrophilicity has been improved after PCGA is grafted onto the surface of PCU film. Scanning electron microscope (SEM) observation of the modified PCU films after contacting with plasma-rich plasma demonstrates that platelets rarely adhere but a large number of platelets adhere to the original PCU surface. The hemocompatibility of the PC modified PCU film has been improved obviously after grafting with PCGA with PEG spacer.

Synthesis and Property of Polyurethane Acrylates Modified Graphene Oxide

2016 ◽  
Vol 703 ◽  
pp. 273-277 ◽  
Author(s):  
Hong Bo Liu ◽  
Wu Ying Zhang ◽  
Feng Lin
Keyword(s):  
Graphene Oxide ◽  
Raman Spectra ◽  
Dimethyl Formamide ◽  
Hydroxyl Groups ◽  
Graphene Oxides ◽  
Ultrasonic Dispersion ◽  
Modified Graphene Oxide ◽  
Infrared Spectrometer ◽  
Modified Graphene ◽  
Scanning Electron

The graphene oxides were synthesized form graphite by ultrasonic dispersion in water, N-methylpyrrolidone (NMP), N,N-dimethyl-formamide (DMF), acetone and dimethylbenzene, and the polyurethane acrylates containing the reactive NCO (PACN) were prepared. Then the polyurethane acrylates modified graphene oxide synthesized by ultrasonic dispersion in N-methylpyrrolidone (NMP), N,N-dimethyl-formamide (DMF), acetone were prepared by NCO of PACN reacting with the hydroxyl groups of the graphene oxides. The polyurethane acrylates modified graphene oxide was characterized by Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM) and Raman spectra. The FTIR spectra showed that the NCO of PACN reacted with the hydroxyl groups of graphene oxide synthesized by ultrasonic dispersion. The measurement of SEM and Raman spectra showed that the polyurethane acrylates modification didn't change the structure and surface morphology of graphene oxide.

scholarly journals Enhanced Performance of PVDF Composite Ultrafiltration Membrane via Degradation of Collagen-Modified Graphene Oxide

2021 ◽  
Vol 11 (23) ◽  
pp. 11513
Author(s):  
Yonggang Hou ◽  
Shenghua Lv ◽  
Haoyan Hu ◽  
Xinming Wu ◽  
Leipeng Liu
Keyword(s):  
Graphene Oxide ◽  
Polyvinylidene Fluoride ◽  
Membrane Surface ◽  
Water Flux ◽  
Ultrafiltration Membrane ◽  
Carboxyl Content ◽  
Modified Graphene Oxide ◽  
Leather Waste ◽  
Improved Performance ◽  
Modified Graphene

The collagen obtained from chrome leather waste can be used to modify graphene oxide (GO) to prepare polyvinylidene fluoride (PVDF) composite ultrafiltration membranes, a process that is conducive to the recovery of leather waste, comprehensive utilization of GO and improved performance of the membrane. In this paper, collagen-modified GO (CGO) was prepared by degradation of collagen from chrome leather waste and used to prepare a PVDF composite ultrafiltration membrane. The results show that the carboxyl content of CGO and dispersion were improved. The water flux and flux recovery rate of the modified ultrafiltration membrane were improved. The bovine serum albumin (BSA) intercepted on the membrane surface was easy to clean and the antifouling performance improved. The performance of the membrane decreased when the GO content exceeded 0.75 wt%, while CGO can reach 1.0 wt% without agglomeration due to its good dispersion.

scholarly journals Color Removal from Wastewater using a Synthetic High Performance Antifouling GO-CPTMS@Pd-TKHPP/Polyether Sulfone Nanofiltration Membrane

2021 ◽  
Author(s):  
foad gholami ◽  
sirus zinadini ◽  
Soheila Nakhjiri Kamrani ◽  
ali akbar zinatizadeh ◽  
Kiumars Bahrami
Keyword(s):  
Graphene Oxide ◽  
High Performance ◽  
Pure Water ◽  
Water Flux ◽  
Nanofiltration Membrane ◽  
Powdered Milk ◽  
Water Contact ◽  
Polyether Sulfone ◽  
Modified Graphene Oxide ◽  
Modified Graphene

Abstract Modified graphene oxide with 5,10,15,20-tetrakis‐(4‐hexyloxyphenyl) ‐porphyrin and palladium (II) (signified by GO-CPTMS@Pd-TKHPP) prepared as a novel antifouling polyether sulfone (PES) blended nanofiller membrane. The membrane efficiency has been analyzed such as pure water flux (PWF), hydrophilicity and antifouling features. By increasing of modified graphene oxide percentage from 0 to 0.1 wt.% in polymer matrix the PWF was incremented from 14.35 to 37.33 kg/m2.h at 4bar. The membrane flux recovery ratio (FRR) has been investigated by applying powdered milk solution, the FRR results indicated that the 0.1 wt.% modified graphene oxide membrane showed the positive effect on fouling behavior with Rir and FRR value 8.24 and 91.73% respectively. The nanofiltration membrane performance was assessed applying the Direct Red 16 dye rejection. It was demonstrated that the optimal membranes (0.1 wt.% modified graphene oxide) had notable dye removal (99.58 % rejection). The results are also verified by measuring the scanning electron microscopy (SEM), water contact angle (WCA) and atomic microscopy analysis (AFM).

scholarly journals Hydrophobic Modification of Graphene Oxide and Its Effect on the Corrosion Resistance of Silicone-Modified Epoxy Resin

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 89
Author(s):  
Wei Yuan ◽  
Qian Hu ◽  
Jiao Zhang ◽  
Feng Huang ◽  
Jing Liu
Keyword(s):  
Contact Angle ◽  
Corrosion Resistance ◽  
Graphene Oxide ◽  
Physical Properties ◽  
Epoxy Resin ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
X Ray ◽  
Modified Graphene Oxide ◽  
Modified Epoxy

This study modified graphene oxide (GO) with hydrophilic octadecylamine (ODA) via covalent bonding to improve its dispersion in silicone-modified epoxy resin (SMER) coatings. The structural and physical properties of ODA-GO were characterized by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and contact angle tests. The ODA-GO composite materials were added to SMER coatings by physical mixing. FE-SEM, water absorption, and contact angle tests were used to evaluate the physical properties of the ODA-GO/SMER coatings, while salt spray, electrochemical impedance spectroscopy (EIS), and scanning Kelvin probe (SKP) methods were used to test the anticorrosive performance of ODA-GO/SMER composite coatings on Q235 steel substrates. It was found that ODA was successfully grafted onto the surfaces of GO. The resulting ODA-GO material exhibited good hydrophobicity and dispersion in SMER coatings. The anticorrosive properties of the ODA-GO/SMER coatings were significantly improved due to the increased interfacial adhesion between the nanosheets and SMER, lengthening of the corrosive solution diffusion path, and increased cathodic peeling resistance. The 1 wt.% ODA-GO/SMER coating provided the best corrosion resistance than SMER coatings with other amounts of ODA-GO (including no addition). After immersion in 3.5 wt.% NaCl solution for 28 days, the low-frequency end impedance value of the 1 wt.% ODA-GO/SMER coating remained high, at 6.2 × 108 Ω·cm2.

scholarly journals Design, synthesis, and catalytic performance of modified graphene oxide based on a cobalt complex as a heterogenous catalyst for the preparation of aminonaphthoquinone derivatives

RSC Advances ◽  
2021 ◽  
Vol 11 (28) ◽  
pp. 17108-17115
Author(s):  
Mahnaz Mirheidari ◽  
Javad Safaei-Ghomi
Keyword(s):  
Graphene Oxide ◽  
Cobalt Complex ◽  
Catalytic Performance ◽  
Silica Particles ◽  
Design Synthesis ◽  
Spherical Silica ◽  
Modified Graphene Oxide ◽  
Spherical Silica Particles ◽  
Heterogenous Catalyst ◽  
Modified Graphene

GO@f-SiO2@Co is a heterogenous catalyst composed of spherical silica particles grafted on the surface of graphene oxide with ethylenediamine ligands and coordination with Co(ii). We assessed the activity of the catalyst for the synthesis of aminonaphthoquinones.

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