visible spectroscopy
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2022 ◽  
Author(s):  
Md. Shamsul Alam ◽  
Md. Sabbir Hasan ◽  
Jannat Al Foisal ◽  
G. M. Arifuzzaman Khan ◽  
Rownok Jahan ◽  
...  

Abstract Modification of cellulose with silver nanoparticles produces various nanocomposites with significantly developed properties. This work aims to prepare a PVA hydrogel modified with cellulose/silver nanocomposites having potential applications in various fields including biomedical, antimicrobial inhibition, textile wears, etc. Microfibrillated cellulose/silver nanocomposites hydrogels were prepared in the aqueous medium with aid of microwave-assisted heating. Different percentages of nanocomposites were incorporated in PVA hydrogel to enhance the properties of PVA hydrogel. Prepared products were characterized by UV-Visible spectroscopy, FTIR, TGA, XRD, and SEM. The swelling (in water saline, acidic and alkaline solution), tensile, thermal, and antibacterial properties were also examined. The formation of Ag nanoparticles (AgNPs) in the (MFC-Ag) NC was confirmed by XRD and UV–Vis spectra. UV–Vis spectra showed the characteristic peaks of Ag in the UV–Vis spectra at 425 nm. Final products exhibited significant porosity and maximum swelling of 519.44%. The thermal stability of hydrogel increased with an increased percentage of (MFC-Ag)NC. Hydrogels exhibited significant antimicrobial inhibition against multidrug-resistant microorganisms, including Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.


Catalysts ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 61
Author(s):  
Adrien P. Yepseu ◽  
Thomas Girardet ◽  
Linda D. Nyamen ◽  
Solenne Fleutot ◽  
Kevin I. Y. Ketchemen ◽  
...  

In this study, two copper(II) complexes, [Cu(C6H8N3S2)2]Cl2 (1) and [Cu(C7H10N3S2)2]Cl2·H2O (2), were synthesized from 2-(thiophen-2-ylmethylene)hydrazine-1-carbothioamide (L1H) and 2-(1-(thiophen-2-yl)ethylidene)hydrazine-1-carbothioamide (L2H) respectively and characterized using various spectroscopic techniques and elemental analyses. The as-prepared complexes were used as single-source precursors for the synthesis of oleylamine-capped (OLA@CuxSy), hexadecylamine-capped (HDA@CuxSy), and dodecylamine-capped (DDA@CuxSy) copper sulphide nanoparticles (NPs) via the thermolysis method at 190 °C and 230 °C and then characterized using powder X-ray diffraction (p-XRD), UV-visible spectroscopy, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The p-XRD diffraction patterns confirmed the formation of crystalline rhombohedral digenite Cu9S5 with the space group R-3m. The TEM images showed the formation of nanoparticles of various shapes including hexagonal, rectangular, cubic, truncated-triangular, and irregularly shaped Cu9S5 nanomaterials. The SEM results showed aggregates and clusters as well as the presence of pores on the surfaces of nanoparticles synthesized at 190 °C. The UV-visible spectroscopy revealed a general blue shift observed in the absorption band edge of the copper sulphide NPs, as compared to bulk CuxSy, with energy band gaps ranging from 2.52 to 3.00 eV. Energy-dispersive X-ray spectroscopy (EDX) confirmed the elemental composition of the Cu9S5 nanoparticles. The nanoparticles obtained at 190 °C and 230 °C were used as catalysts for the photocatalytic degradation of methylene blue (MB) under UV irradiation. Degradation rates varying from 47.1% to 80.0% were obtained after 90 min of exposure time using only 10 mg of the catalyst, indicating that Cu9S5 nanoparticles have potential in the degradation of organic pollutants (dyes).


2021 ◽  
Vol 10 (4) ◽  
pp. 19-21
Author(s):  
V. Gayathri ◽  
R. Balan

In this paper, the synthesis of Zirconium oxide (ZrO2) nanoparticles was carried out by the Conventional precipitation method. Ultraviolet, visible spectroscopy (UV-Vis), and dynamic light scattering analysis (DLS) were performed to find the particles' bandgap and size. Fourier transform infrared spectroscopy (FT-IR) observed the characteristic bands of Zirconium oxide nanoparticles. Dynamic light scattering analysis showed that the size of the particle was found to be 119 nm.


Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1507
Author(s):  
Jayachandran Ashwini ◽  
T. R. Aswathy ◽  
Anil Babu Rahul ◽  
Gautham M. Thara ◽  
Achuthsankar S. Nair

This paper presents the green synthesis and characterization of ZnO nanoparticles and their microbial and photocatalytic application. The green synthesis of ZnO nanoparticles was carried out using Zinc nitrate hexahydrate and the bark extract of Acacia caesia (L.) Willd. The nanoparticles were synthesized at an optimum temperature of 65 °C followed by calcination at 400 °C. The samples were characterized using UV-visible spectroscopy, SEM, XRD, FTIR and EDX analysis. UV-visible spectroscopy showed a characteristic peak at 338 nm and the bandgap energy was found to be 3 eV which is specific for ZnO. SEM confirmed the presence of ZnO on its nanoscale. EDX gave the elemental details of Zinc constituting to 37.77% and Oxygen comprising 20.77% of its atomic weight. XRD analysis gave the diffractogram indexed at various angles corresponding to ZnO nanoparticles. It also revealed the average crystalline size to be 32.32 nm and the shape was found to be hexagonal. The functional group present in the nanoparticles was characterized using FTIR, which gave a characteristic peak at 485 cm−1. The synthesized nanoparticles exhibited significant photocatalytic (methyl blue under UV irradiation). The presence of nanoparticles induces changes in its kinetics, whose rate constants and correlation coefficients were analyzed during the photocatalytic degradation of the model pollutant Methyl Blue. Studies on antibacterial (Escherichia coli, Staphylococcus aureus), antifungal (Aspergillus niger, Candida albicans) and anti-inflammatory (COX assay) properties were also carried out. The nanoparticles were synthesized in an eco-friendly and cost-effective method. The study opens new horizons in the field of water treatment, biosensors and nanotechnology.


2021 ◽  
Vol 2114 (1) ◽  
pp. 012082
Author(s):  
A H AL-Husseini ◽  
B T Sih ◽  
A M Al-Araji

Abstract In this study, iron oxide nanoparticles were prepared using saffron plant extract, and the prepared particles were diagnosed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray resolution (EDX), infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV–Vis). This method falls within the green chemistry, an environmentally friendly method and at a lower cost than other methods


Author(s):  
Ishwari Choudhary ◽  
Preeti K. Suresh

This study was aimed at the development of natamycin loaded nano-structured lipid carriers (NLCs) and their characterization for physicochemical properties i.e., Fourier Transform Infrared (FTIR), UV-Visible spectroscopy, meting point, solubility profile and partition coefficient. FTIR and Differential Scanning Calorimetry (DSC) permit the characterization of the drug, excipients and binary mixture and thus assisted in predicting the compatibility of natamycin with other excipients. Lipid screening for formulation of NLCs were performed by their solubility and drug affinity studies. High homogenization and sonication method was employed for the development of natamycin loaded NLCs and it was characterized for vesicle size, zeta potential, % entrapment efficiency, viscosity, pH and percentage drug release up to 12 h.


Author(s):  
Ksh. Sangeeta Devi ◽  
Atom Rajiv Singh ◽  
D. Velmurugan ◽  
M. Damayanti Devi ◽  
Deepak Singh Lourembam ◽  
...  

Background: Copper oxide nanoparticles(CuO NPs) have been powerful evidence in several in vitro studies such as cytotoxicity and antimicrobial compared with other metal oxide. Here, we have synthesized green CuO NPs using Coix lacryma jobi leaves extracts. Place and Duration of Study: Department of Chemistry  Manipur University, Manipur, India and Regional Institute of Medical Sciences, Imphal, India between February 2019 to March 2021. Methodology: Green CuO NPs nanoparticles were synthesized from Copper chloride dihydrate (CuCl2.2H2O) using Coix lacryma jobi leaves extract, and the synthesized green CuO NPs were characterized using Field Emission Scanning Electron Microscopy (FESEM) - Energy Dispersive Spectroscopy, IR Spectroscopy, UV-Visible Spectroscopy, Powder X-Ray diffraction Spectroscopy and HR-TEM where FESEM-EDS determined the purity of CuO NPs. Results: No other impurities present were observed in EDS, and the PXRD spectra show the crystallite size of CuO NPs with respect to the (002) plane is found to be 25.2 nm, and the presence of CuO NPs at adsorption spectrum with a distinct peak at 282 nm was determined by  UV-Visible spectroscopy and the homogenous morphology and crystalline nature of the CuO NPs were determined from TEM micrograph and SAED pattern. In applications, the substantial anticancer activity of green CuO NPs (synthesized using Coix lacryma jobi leaves extract) was proved on human cervical and lung cancer cell lines with IC50 values of 31.88 μg/ml and 15.61 μg/ml, respectively.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Younes Ziat ◽  
Hamza Belkhanchi ◽  
Maryama Hammi ◽  
Ousama Ifguis

Thin films of epoxy/silicone loaded with N-CNT were prepared by a method of sol-gel and deposited on ITO glass substrates at room temperature. The properties of the loaded monolayer samples (0.00, 0.07, 0.1, and 0.2 wt% N-CNTs) were analyzed by UV-visible spectroscopy. The transmittance for the unloaded thin films is 88%, and an average transmittance for the loaded thin film is about 42 to 67% in the visible range. The optical properties were studied from UV-visible spectroscopy to examine the transmission spectrum, optical gap, Tauc verified optical gap, and Urbach energy, based on the envelope method proposed by Swanepoel (1983). The results indicate that the adjusted optical gap of the film has a direct optical transition with an optical gap of 3.61 eV for unloaded thin films and 3.55 to 3.19 eV for loaded thin films depending on the loading rate. The optical gap is appropriately adapted to the direct transition model proposed by Tauc et al. (1966); its value was 3.6 eV for unloaded thin films and from 3.38 to 3.1 eV for loaded thin films; then, we determined the Urbach energy which is inversely variable with the optical gap, where Urbach’s energy is 0.19 eV for the unloaded thin films and varies from 0.43 to 1.33 eV for the loaded thin films with increasing rate of N-CNTs. Finally, nanocomposite epoxy/silicone N-CNT films can be developed as electrically conductive materials with specific optical characteristics, giving the possibility to be used in electrooptical applications.


Author(s):  
Haribabu Y. ◽  
Nihila K. ◽  
Sheeja VK. ◽  
Akhil MB.

Pharmaceutical medicines play an important role in human life that helps to cure different diseases. For the chemical and pharmaceutical analysis of the drug effective quality control and pharmacodynamic and pharmacokinetic studies are needed. Several methods have been developed and validated for its pharmaceutical and biological materials since it was introduced as an important antiretroviral agent. The literature survey reveals that only four RP HPLC method and one HPTLC was developed for the simultaneous estimation of Dolutegravir, Lamivudine and Tenofovir disoproxil fumarate in tablet dosage form. These three drugs are used as antiretroviral medicines which are used for HIV or AIDS prevention and treatment. The goal of this review is to define and establish a simple, precise and selective method for estimating the dosage of Lamivudine, Tenofovir Disoproxil fumarate and Dolutegravir in biological and pharmaceutical dosage form using the HPLC, HPTLC, UPLC, UV Visible spectroscopy, LC/MS, Infrared spectroscopy, NMR spectroscopy, Microbiological assay, Electrochemical studies and Capillary electrophoresis. UV-detector HPLC is commonly used in pharmaceuticals and LC-MS are widely used for biological materials with mass and tandem mass spectrometer detector systems. Various parameters such as device suitability, process accuracy, precision, linearity, detection limit will validate the UV Visible spectroscopy and RP-HPLC technique.


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