Incorporation Of Graphite Oxide Research Articles

Effect of graphite oxide on the mechanical, thermal, structural and hydrophilicity proprieties of Polypropylene / Poly(Propylene-Glycol) Acrylate / Glycidyl Methacrylate PP/PPGA/GMA composite

This research aims to investigate the synergistic effects of grafting flexible fractions and incorporating reinforcing fillers in polypropylene (PP) matrix. The primary objective is to establish an experimental methodology for preparing and characterizing Polypropylene / Poly(Propylene-Glycol) Acrylate / Glycidyl Methacrylate (PP/PPGA/GMA) composites loaded with graphite oxide (GtO).The process of oxidizing natural graphite powder using a mixture of sulfuric acid and nitric acid was validated through various analytical techniques including IRTF, AFM, DRX, XRF and ATG. The grafting reaction of PPGA and GMA on polypropylene and the incorporation of graphite oxide with varying levels were carried out in the melt state in a Brabender internal mixer; Dicumyl peroxide (DCP) was used as a radical initiator. A comprehensive assessment of the obtained materials was conducted through conventional analyses encompassing mechanical properties (tensile and impact), thermal behaviors (ATG and DSC), morphological characteristics (SEM) and the chemical state of film surfaces (Contact angle).The investigation revealed two key outcomes. Firstly, it showcased the grafting effect of PP on the polymer's morphology and properties. Secondly, it underscored the consequential impact of incorporating graphite oxide on the overall behavior of produced materials.

Enhancement of the Solubility of BS Class II Drugs with MOF and MOF/GO Composite Materials: Case Studies of Felodipine, Ketoprofen and Ibuprofen

In this research, a novel composite material composed of Metal-Organic Framework material (MOF) and graphite oxide was synthesized and evaluated as a possible drug-loading vehicle. HKUST-1, a MOF material originally designed by the Hong Kong University of Science and Technology, was used as a model porous material. The aim was to synthesize a drug delivery vehicle for modifying the release kinetics and solubility of poorly soluble drugs (BSC Class II drugs); these are drugs that are known to have poor bioavailability due to their low solubility. We used ketoprofen, ibuprofen, and felodipine as models for BSC Class II drugs. The drugs were loaded onto composite materials through adsorption. The adsorption of these three drugs into the matrix of HKUST-1/GO (graphite oxide), HKUST-1, and graphite oxide was compared. The loading efficiency of the drugs onto the carrier was dependent on the drug molecule and the composition of the drug carrier. The inclusion of graphite oxide in the drug carrier matrix improved the drug loading capacity and modified the drug release rate. The loading of the three drugs felodipine, ketoprofen, and ibuprofen onto HKUST-1 were 33.7, 58, and 79 mg/g respectively. The incorporation of GO into the HKUST-1 matrix resulted in an increase in the loading by 16 and 4 mg/g for the ketoprofen and ibuprofen drugs. When compared to the pure drugs, the solubility of all three drugs in the HKUST-1/GO matrix increased by at least 6 folds.

Synthesis and the Swelling Behavior of Sodium Alginate Graft Poly (Acrylic Acid-co-acrylamide)/Graphite Oxide Super Absorbent Composite

Sodium alginate graft poly(acrylic acid-co-acrylamide)/graphite oxide (P(AA-co-AM)/GO) super absorbent composite was prepared by solution intercalation copolymerization of acrylic acid (AA), acrylamide (AM) and graphite oxide (GO). The composite was characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, transmission electron microscope and differential scanning calorimetry. The effect of reaction conditions, including the mass ratio of monomers, dosages of cross-linker, initiator and GO as well as the neutralization degree of AA, on the absorption capacities of deionized water and 0.9% NaCl was studied. Water retention properties of the composite were also discussed. It was deduced that the interactions between GO and P(AA-co-AM) copolymer were the intermolecular hydrogen bonds. Thermal stabilities of the composite could be improved by the incorporation of GO. Above all, there was a remarkable improvement of absorption capacities owing to the incorporation of GO. Absorption capacities of water and 0.9% NaCl could be improved from 298.6 and 79.2 g/g, respectively, to 870.5 and 183.3 g/g, respectively, as the dosage of GO increased from 0 to 0.1 g. In addition, there was a remarkable improvement of water retention rates. After drying at 25°C for 8 h the water retention rates could be improved up to 17.9% with the incorporation of GO.

Synthesis and Swelling Behavior of Poly(acrylic acid)/Graphite Oxide Superabsorbent Composite

Poly(acrylic acid)/graphite oxide superabsorbent composite was prepared by solution intercalation polymerization of acrylic acid and graphite oxide using N,N-methylene-bis-acrylamide as a cross-linker and potassium persulfate as an initiator. The composite was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscope, powder X-ray diffraction and differential scanning calorimetry. The influence of reaction conditions on water and saline absorption of superabsorbent was studied in details. Water retention properties of the composite were also discussed. The improvement of absorption capacities and the retention rates with the incorporation of graphite oxide was found.

Preparation and absorption properties of poly (acrylic acid‐co‐acrylamide)/graphite oxide superabsorbent composite

AbstractPoly (acrylic acid‐co‐acrylamide)/graphite oxide (P (AA‐co‐AM)/GO) superabsorbent composite was prepared by solution intercalation polymerization of acrylic acid (AA), acrylamide (AM), and graphite oxide (GO). The composite was characterized by Fourier transform infrared spectroscopy, powder X‐ray diffraction, scanning electron microscopy, transmission electron microscope, thermogravimetric analysis , and differential scanning calorimetry. The effect of reaction conditions, including the mass ratio of monomers, dosages of cross‐linker, initiator, and GO as well as the neutralization degree of AA, on water and saline absorption was studied. Water retention properties of the composite were also discussed. It showed that interactions between GO and P (AA‐co‐AM) copolymer were the intermolecular hydrogen bonds. Thermal stabilities of the composite could be improved by the incorporation of GO. Besides, there was a remarkable improvement of absorption capacities owing to the incorporation of GO. Absorption capacities of water and 0.9% NaCl could be improved from 141.7 and 33.6 g/g, respectively, to 809.6 and 131.4 g/g, respectively, as the dosage of GO increased from 0 to 0.1 g. In addition, there was a remarkable improvement of water retention rates. Water retention rates of P(AA‐co‐AM)/GO and P(AA‐co‐AM) were 65.9% and 53.8%, respectively, after drying at 25°C for 8 hr.

Mode I and Mode II interlaminar fracture behavior of E‐glass fiber reinforced epoxy composites modified with reduced exfoliated graphite oxide

In this article, Mode I and Mode II interlaminar fracture toughness, interlaminar shear strength, flexural strength and the flexural modulus of continuous unidirectional E‐glass fiber reinforced epoxy composites modified with three different graphite oxide (GO) fillers were investigated. GO was prepared through modified Hummers' method followed by thermal exfoliation at 200°C to produce exfoliated GO (EGO). Further, EGO was chemically reduced to result in reduced EGO (rEGO). Incorporation of GO and EGO fillers exhibited significant improvement in the mechanical properties of the composites. Remarkable enhancement in mechanical properties was observed with rEGO fillers, where Mode I and Mode II fracture toughness values of composites were increased by 65% (0.5 wt%) and 54% (0.25 wt%), respectively. Studies on nanofillers distribution in the matrix resin and the examination of fracture surfaces of specimens were carried out with field emission scanning electron microscopy. POLYM. COMPOS., 39:E2506–E2518, 2018. © 2018 Society of Plastics Engineers

Chitosan–graphene oxide nanocomposites: Effect of graphene oxide nanosheets and glycerol plasticizer on thermal and mechanical properties

ABSTRACTIn this study, graphite oxide (GO) is synthesized from natural graphite flakes by the modified Hummers method. Characterization by Fourier transform infrared, X‐ray photoelectron, Raman and ultraviolet‐visible spectroscopies, X‐ray diffraction, and thermogravimetric analysis is conducted on GO to confirm the oxidation of graphite. Unplasticized and glycerol plasticized chitosan/graphene oxide (CS/GO) nanosheets nanocomposites with different GO loadings are prepared by solution casting. The combined effect of GO and glycerol on structure, thermal and mechanical properties of nanocomposite films is studied. GO nanosheets are well dispersed throughout the CS matrix due to the hydrogen bonding and electrostatic interactions between CS and GO nanosheets. The incorporation of GO within the CS matrix results in a decrease of the crystallinity, an improvement of thermal stability, and a significant enhancement of the stiffness and tensile strength that is emphasized by the glycerol. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45092.

Sulfidation of NiMn‐Layered Double Hydroxides/Graphene Oxide Composites toward Supercapacitor Electrodes with Enhanced Performance

Supercapacitors can deliver high‐power density and long cycle stability, but the limited energy density due to poor electronic and ionic conductivity of the supercapacitor electrode has been a bottleneck in many applications. A strategy to prepare microflower‐like NiMn‐layered double hydroxides (LDH) with sulfidation is delineated to reduce the charge transfer resistance of supercapacitor electrode and realize faster reversible redox reactions with notably enhanced specific capacitance. The incorporation of graphite oxide (GO) in NiMn LDH during sulfidation leads to simultaneous reduction of GO with enhanced conductivity, lessened defects, and doping of S into the graphitic structure. Cycling stability of the sulfidized composite electrode is enhanced due to the alleviation of phase transformation during electrochemical cycling test. As a result, this sulfidation product of LDH/GO (or LDHGOS) can reach a high‐specific capacitance of 2246.63 F g−1 at a current density of 1 A g−1, and a capacitance of 1670.83 F g−1 is retained at a high‐current density of 10 A g−1, exhibiting an outstanding capacitance and rate performance. The cycling retention of the LDHGOS electrode is also extended to ≈ 67% after 1500 cycles compared to only ≈44% of the pristine NiMn LDH.

Role of surface chemistry and morphology in the reactive adsorption of H₂S on iron (hydr)oxide/graphite oxide composites.

Composites of magnetite and two-line ferrihydrite with graphite oxide (GO) were synthesized and tested as hydrogen sulfide adsorbents. Exhausted and initial composites were characterized by the adsorption of nitrogen, X-ray diffraction, potentiometric titration, thermal analysis, and FTIR. The addition of GO increased the surface area of the composites due to the formation of new micropores. The extent of the increase depended on the nature of the iron (hydr)oxide and the content of GO. The addition of GO did not considerably change the crystal structure but increased the number of acidic functional groups. While for the magnetite composites an increase in the H2S adsorption capacity after GO addition was found, the opposite effect was recorded for the ferrihydrite composites. That increase in the adsorption capacity was linked to the affinity of the composites to adsorb water in mesopores of specific sizes in which the reaction with basic surface groups takes place. Elemental sulfur and ferric and ferrous sulfates were detected on the surface of the exhausted samples. A redox reactive adsorption mechanism is proposed to govern the retention of hydrogen sulfide on the surface of the composites. The incorporation of GO enhances the chemical retention of H2S due to the incorporation of OH reactive groups and an increase in surface heterogeneity.

Metal-organic framework-199/graphite oxide hybrid composites coated solid-phase microextraction fibers coupled with gas chromatography for determination of organochlorine pesticides from complicated samples

The hybrid material of a copper-based metal-organic framework (MOF-199) and graphite oxide (GO) was explored as the solid-phase microextraction (SPME) coating for the first time. This fiber was fabricated by using 3-amino-propyltriethoxysilane (APTES) as the cross-linking agent, which enhanced its durability and allowed more than 140 replicate extractions. With the incorporation of GO, the MOF-199/GO fibers with GO contents ranging from 5 to 15wt% exhibited enhanced adsorption affinity to organochlorine pesticides (OCPs) compared to MOF or GO individually. This improvement was linked to the enhanced dispersive forces (increased volume of small pores) that provided by the dense carbon layers of GO. Combining the superior properties of high porosity of MOFs and the unique layered character of GO, the MOF-199/GO (10wt%) fiber exhibited higher adsorption affinity to some OCPs than commercial polydimethylsiloxane (PDMS) and polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibers. This new fiber was developed for headspace (HS) SPME of eight OCPs followed by GC/ECD analysis. The limits of detection were 2.3–6.9ng/L. The relative standard deviation (RSD) for five replicate extractions using one fiber ranged from 5.3% to 8.8%. The fiber-to-fiber reproducibility was 5.2–12.8%. This method was successfully used for simultaneous determination of eight OCPs from river water, soil, water convolvulus and longan with satisfactory recoveries of 90.6–104.4%, 82.7–96.8%, 72.2–107.7% and 82.8–94.3%, respectively. These results indicated the MOF-199/GO composite provided a promising alternative in sample pretreatment.

A new poly( l-lactide)-grafted graphite oxide composite: Facile synthesis, electrical properties and crystallization behaviors

A simple method was adopted to prepare poly( l-lactide)-grafted graphite oxide (PLLA-g-GO) by ring opening polymerization of l-lactide in the presence of graphite oxide (GO) with hydroxyl groups. GO was firstly treated with tolylene-2,4-diisocyanate (TDI) to create an anchor site on GO, and then reacted with 1,4-butanediol (BD) to afford functional hydroxyl groups grafted onto the surface of GO. So that, the dispersity of GO in the organic solution was enhanced. According to the thermogravimetric analysis (TGA), the organic composition of GO treated with TDI and BD (GO-TDI-OH) was estimated to be about 13 wt%. Also, using TGA, the composition of GO in the PLLA-g-GOs could be estimated. The hydroxyl groups on the GO surface acted as initiators for the ROP of l-lactide. Further, they also played as a vital role in controlling the molecular weight of the PLLA. The synthesized PLLA-g-GOs were characterized by the FTIR, 1HNMR and UV/Vis spectroscopies. The dispersion states of GO in the PLLA-g-GOs were investigated by wide angle x-ray diffraction patterns. According to differential scanning calorimeter study, it was found that GO platelets have nucleating effect on the crystallization of PLLA in the PLLA-g-GO. Additionally, the incorporation of GO improved the electrical conductivity of PLLA, indicating that GOs is a good conducting-modifiers for polymers.