Graphene oxide reinforced polyvinyl alcohol/polyethylene glycol blend composites as high-performance dielectric material

2016 ◽  
Vol 23 (8) ◽  
Author(s):  
Kalim Deshmukh ◽  
M. Basheer Ahamed ◽  
Kishor Kumar Sadasivuni ◽  
Deepalekshmi Ponnamma ◽  
Rajendra R. Deshmukh ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Polyethylene Glycol ◽  
Polyvinyl Alcohol ◽  
High Performance ◽  
Dielectric Material

Facile Strategy to Construct High-Performance Nanofiltration Membranes by Synergy of Graphene Oxide and Polyvinyl Alcohol

2020 ◽  
Vol 59 (42) ◽  
pp. 19001-19011
Author(s):  
Lufang Shen ◽  
Quanling Xie ◽  
Zhuan Hong ◽  
Chenpu Wu ◽  
Tong Yu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Polyvinyl Alcohol ◽  
High Performance ◽  
Nanofiltration Membranes

Development and Validation of a Novel Reversed Phase High Performance Liquid Chromatography with Refractive Index Detector Method for Assay of Polyvinyl Alcohol in an Ophthalmic Solution

2020 ◽  
Vol 16 (7) ◽  
pp. 867-871
Author(s):  
Harun Ergen ◽  
Muge Guleli ◽  
Cigdem Sener ◽  
Cem Caliskan ◽  
Sercan Semiz ◽  
...  
Keyword(s):  
Refractive Index ◽  
Liquid Chromatography ◽  
Polyvinyl Alcohol ◽  
High Performance ◽  
Ophthalmic Solution ◽  
Reversed Phase ◽  
Hplc Method ◽  
Solution Stability ◽  
Technical Requirements ◽  
Refractive Index Detector

Introduction: Polyvinyl alcohol (PVA), a polymer, is in demand due to its usage in different applications such as pharmaceutical, biomedical and textile, paper, food industries. Methods: A new sensitive reversed phased high-pressure liquid chromatography (RP-HPLC) method with refractive index detector (RID) was developed for determination of PVA in an ophthalmic solution containing dexpanthenol and PVA as active substances and it was validated according to The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guideline. Results: Chromatographic separation was achieved on a Chiral-AGP (150 mm × 4.0 mm, 5 μm) column kept at 30°C with an isocratic flow at a flow rate of 1.0 ml/min. The detector temperature was 30°C, the retention time of PVA was around 1.0 min and the total run time was 5 minutes. Conclusion: The proposed method showed linearity, accuracy, precision, specificity, robustness, solution stability, and system suitability results within the acceptance criteria.

scholarly journals Polyethylene Glycol Functionalized Graphene Oxide Nanoparticles Loaded with Nigella sativa Extract: A Smart Antibacterial Therapeutic Drug Delivery System

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3067
Author(s):  
Mustafa A. Jihad ◽  
Farah T. M. Noori ◽  
Majid S. Jabir ◽  
Salim Albukhaty ◽  
Faizah A. AlMalki ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Grain Size ◽  
Cell Wall ◽  
Graphene Oxide ◽  
Polyethylene Glycol ◽  
Nucleic Acid ◽  
Drug Delivery System ◽  
Delivery System ◽  
Nigella Sativa ◽  
Seed Extract

Flaky graphene oxide (GO) nanoparticles (NPs) were synthesized using Hummer’s method and then capped with polyethylene glycol (PEG) by an esterification reaction, then loaded with Nigella sativa (N. sativa) seed extract. Aiming to investigate their potential use as a smart drug delivery system against Staphylococcus aureus and Escherichia coli, the spectral and structural characteristics of GO-PEG NPs were comprehensively analyzed by XRD, AFM, TEM, FTIR, and UV- Vis. XRD patterns revealed that GO-PEG had different crystalline structures and defects, as well as a higher interlayer spacing. AFM results showed GONPs with the main grain size of 24.41 nm, while GONPs–PEG revealed graphene oxide aggregation with the main grain size of 287.04 nm after loading N. sativa seed extract, which was verified by TEM examination. A strong OH bond appeared in FTIR spectra. Furthermore, UV- Vis absorbance peaks at (275, 284, 324, and 327) nm seemed to be correlated with GONPs, GO–PEG, N. sativa seed extract, and GO –PEG- N. sativa extract. The drug delivery system was observed to destroy the bacteria by permeating the bacterial nucleic acid and cytoplasmic membrane, resulting in the loss of cell wall integrity, nucleic acid damage, and increased cell-wall permeability.

Synthesis and Characterization of Reduced Graphene Oxide

2013 ◽  
Vol 678 ◽  
pp. 56-60 ◽  
Author(s):  
Cherukutty Ramakrishnan Minitha ◽  
Ramasamy Thangavelu Rajendrakumar
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Graphite Oxide ◽  
High Performance ◽  
Structural Changes ◽  
Epoxy Group ◽  
Xrd Analysis ◽  
Si Substrates ◽  
Reduced Graphene ◽  
Reduced Graphite Oxide

Reduced graphene oxide is an excellent candidate for various electronic devices such as high performance gas sensors. In this work Graphene oxide was prepared by oxidizing graphite to form graphite oxide. From XRD analysis the peak around 11.5o confirmed that the oxygen was intercalated into graphite. By using hydrazine hydrate, the epoxy group in graphite oxide was reduced then the solution of reduced graphite oxide (rGO) is exfoliated. Raman spectrum of rGO contains both G band (1580 cm-1), D band (1350 cm-1). The remarkable structural changes reveals that reduction of graphene oxide from the values of ID/IG ratio that increase from 0.727 (GO) to 1.414 (rGO). The exfoliated reduced graphite oxide solution is spin coated on to the SiO2/Si substrates.

scholarly journals Tuning the hierarchical pore structure of graphene oxide through dual thermal activation for high-performance supercapacitor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeongpil Kim ◽  
Jeong-Hyun Eum ◽  
Junhyeok Kang ◽  
Ohchan Kwon ◽  
Hansung Kim ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Pore Structure ◽  
Specific Capacitance ◽  
Surface Area ◽  
Thermal Annealing ◽  
High Performance ◽  
Annealing Process ◽  
Supercapacitor Electrode ◽  
Simple Method ◽  
Surface Areas

AbstractHerein, we introduce a simple method to prepare hierarchical graphene with a tunable pore structure by activating graphene oxide (GO) with a two-step thermal annealing process. First, GO was treated at 600 °C by rapid thermal annealing in air, followed by subsequent thermal annealing in N2. The prepared graphene powder comprised abundant slit nanopores and micropores, showing a large specific surface area of 653.2 m2/g with a microporous surface area of 367.2 m2/g under optimized conditions. The pore structure was easily tunable by controlling the oxidation degree of GO and by the second annealing process. When the graphene powder was used as the supercapacitor electrode, a specific capacitance of 372.1 F/g was achieved at 0.5 A/g in 1 M H2SO4 electrolyte, which is a significantly enhanced value compared to that obtained using activated carbon and commercial reduced GO. The performance of the supercapacitor was highly stable, showing 103.8% retention of specific capacitance after 10,000 cycles at 10 A/g. The influence of pore structure on the supercapacitor performance was systematically investigated by varying the ratio of micro- and external surface areas of graphene.

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