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2022 ◽  
Vol 3 (2) ◽  
Gboyega Oluwaseun Oyeleke ◽  
Ibraheem Abimbade Abdulazeez ◽  
Ajisola Agnes Adebisi ◽  
Kehinde Nasiru Oyekanmi ◽  
Segun Olaitan Akinbode

Three solvents of different polarities (water, methanol and 1% NaOHsolution) were used to extract dyes that produced different shades fromdried sunflower (Helianthus annuus) petal. The extraction proceduresusing different solvent types were carried out separately. The dye extractswere thereafter subjected to Fourier Transform Infrared Spectrometry(FT-IR) analysis for characterization in terms of functional groups. Theintensities of the extracted dyes on the shade of colours obtained on piecesof cotton material varied from yellow in methanolic extract to light yellowin aqueous and black in 1% NaOH solution extracts. The results obtainedfrom the FT-IR analysis revealed the presence of several useful functionalgroups such as N-H, C=H, O-H and C=O in the extracts.

2022 ◽  
Vol 58 (4) ◽  
pp. 65-72
Andra Mihaela Onas ◽  
Iuliana Elena Biru ◽  
Aida Petca ◽  
Razvan Cosmin Petca

Ureteral catheters, commonly known as double j stents according to their specific shape, are largely used worldwide with good results to assure proper renal drainage and to overpass ureteral obstacles successfully. This study deals with the aging behavior of polyurethane-based urinary catheters, explanted at different time intervals: 22 days, 29 days, three months, and eight months respectively. TGA (Thermogravimetric analyses) tests showed significant differences in the thermal behavior of polyurethane-based material, especially at eight months, where a higher thermostability was noticed. Also, the DSC (Differential Scanning Calorimetry) curves presented different shapes for the samples of polyurethane-based urinary catheters after three months and eight months. FTIR (Fourier-Transform Infrared Spectrometry) spectra gave a detailed picture of the chemical trans-formation which has occurred within the material at eight months. All the analyses gave an overview of the aging process of polyurethane-based urinary catheters and showed insights into the chemical/ physical transformations that the polymeric material suffers from prolonged usage.

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 36
Tiefeng Zhang ◽  
Chunfeng Wang ◽  
Yongliang Wang ◽  
Lijun Qian ◽  
Zhidong Han

A polymer ceramic precursor material—polycarbosilane (PCS)—was used as a synergistic additive with magnesium hydroxide (MH) in flame-retardant ethylene–vinyl acetate copolymer (EVA) composites via the melt-blending method. The flame-retardant properties of EVA/MH/PCS were evaluated by the limiting oxygen index (LOI) and a cone calorimeter (CONE). The results revealed a dramatic synergistic effect between PCS and MH, showing a 114% increase in the LOI value and a 46% decrease in the peak heat release rate (pHRR) with the addition of 2 wt.% PCS to the EVA/MH composite. Further study of the residual char by scanning electron microscopy (SEM) proved that a cohesive and compact char formed due to the ceramization of PCS and close packing of spherical magnesium oxide particles. Thermogravimetric analysis coupled with Fourier-transform infrared spectrometry (TG–FTIR) and pyrolysis–gas chromatography coupled with mass spectrometry (Py–GC/MS) were applied to investigate the flame-retardant mechanism of EVA/MH/PCS. The synergistic effect between PCS and MH exerted an impact on the thermal degradation products of EVA/MH/PCS, and acetic products were inhibited in the gas phase.

2021 ◽  
Vol 22 (2) ◽  
pp. 344-357
Ketema Beyecha Hundie

The concept of waste to valuable products is a hot topic with exploring ongoing worldwide to minimize food-based feedstocks. This work utilized a citric acid solution and an ultrasoundassisted to extract pectin from orange waste, a critical agroindustry byproduct. Artificial neural network and central composite design were utilized to assess the extraction of pectin using different levels of the extraction parameters and in turn to optimize the extraction process. The extraction of pectin from orange waste is found to be highly affected by pH solution and ultrasound power. The result of an artificial neural network was found to be better in terms of prediction capability and performance indexes. Fourier transform infrared spectrometry analysis confirmed the existence of functional groups in the fingerprint region of orange waste pectin. Ash and crude protein content of orange wastes are found to be low; meaning low ash and protein content contributes to better gelling ability of the pectin. The extracted pectin has a higher degree of esterification. The result of the current work highlighted that orange wastes are a good source of pectin. In addition, the extracted pectin from orange wastes can be used as a food additive as it fulfills all the standard requirements pectin for application.

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Abbas Khodabakhshi ◽  
Fazel Mohammadi-Moghadam ◽  
Mohammad Mehdi Amin ◽  
Sara Hamati ◽  
Shakila Hayarian

Paraquat is the most important herbicide of the bipyridyl group. The aim of the present study was to compare the removal of paraquat herbicide from aqueous solutions using nanoscale zero-valent iron-pumice/diatomite composites. In this study, nZVI was supported with diatomite and pumice. Scanning electron microscopy (SEM) analysis, X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectrometry (FTIR), and specific surface area tests (BET) were used to evaluate the properties of nanoadsorbents. The residual concentration of paraquat in aqueous solution was detected by high-performance liquid chromatography (HPLC). Then, the effects of different variables including the pollutant concentration, contact time, temperature, adsorbents (D-nZVI and P-nZVI) dose, and pH, were investigated in a lab scale batch system. The results showed that the optimal pH for both processes was 3.74. In optimal conditions, the efficiencies of D-nZVI and P-nZVI were 92.76% and 85.28%, respectively. In addition, isotherm and adsorption kinetics studies indicated that P-nZVI follows the Langmuir and Freundlich isotherm models, and D-nZVI follows the Langmuir isotherm model, and both processes follow pseudo-second-order kinetics. The results indicated that the synthesized nanoparticles were suitable for removing paraquat from aqueous solutions. Both adsorbents were found to be very effective in removing similar compounds at ambient temperature in a short time.

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7787
Matías Fernández ◽  
Gustavo Canon ◽  
Sabine Leischner ◽  
Mrinali Rochlani ◽  
José Norambuena-Contreras ◽  

Microwave heating of asphalt pavement is a promising technique to reduce the maintenance and increase the service life of materials through self-healing of cracks. Previous studies have shown that microwave heating technology at high temperatures could damage the bitumen of asphalt mixture, which is an unwanted effect of the crack-healing technique. In this study, the effects of microwave heating and long-term aging on the rheological and chemical properties of recovered bitumen were quantified using a frequency sweep test and Fourier Transform Infrared Spectrometry analysis, respectively. The main results indicate that microwave heating has no significant effect on the aging performance of G* and δ for aged asphalt mixtures. However, for newer bitumens, the rheological properties G* and δ show minor changes after microwave heating was applied. Overall, this study confirms that microwave heating is a potential alternative for maintenance of asphalt pavements, without severely affecting the rheological and chemical properties of bitumen.

Applied Nano ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 344-358
Daiana A. Bravo Fuchineco ◽  
Angélica C. Heredia ◽  
Sandra M. Mendoza ◽  
Enrique Rodríguez-Castellón ◽  
Mónica E. Crivello

The massive use of petroleum and its possible exhaustion are driving the current research trend to study alternative raw materials from biomass for organic reactions. In this context, the present article presents a study of the catalytic esterification of levulinic acid, a platform molecule, with ethanol. Metal-organic framework (MOF) type compounds UiO-66-NH2 have been synthesized. Zirconium was incorporated, using zirconium chloride as a metal precursor, together with 2-aminoterephthalic acid as an organic binding agent. An alternative route of synthesis was proposed using more favorable conditions from an economic and environmental point of view, replacing dimethylformamide by 50 and 75% acetone as substitute solvent. The physicochemical properties of the materials were evaluated by X-ray diffraction (XRD), Infrared Spectrometry with Fourier Transform (FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), microwave plasma atomic emission spectroscopy (MP-AES) and N2 adsorption to understand their morphology, crystalline, chemical and pore structure. The progress of the reaction was followed by gas chromatography and mass spectroscopy. The catalytic activity result of MOF25% in autoclave reactor, showed 100% of selectivity to ethyl levulinate and a turnover number (TON) of 66.18 moles of product/moles of Zr. This good catalytic performance obtained by partial solvent replacement in the synthetic material provides a more economical and eco-friendly process for ethyl levulinate generation.

Jitendra Gupta ◽  
Reena Gupta

Aims: The present research was carried out to investigate the effect of hydrophilic carriers in enhancing the solubility and dissolution rate of Sulfamerazine (SMZ) employing the fusion technique of solid dispersions (SD). Methodology: SMZ is an oral antibacterial drug exhibiting a poor dissolution profile and water solubility. SD of SMZ was prepared using poloxamer 407 (PX407) and Polyethylene glycol 6000 (PEG6000) as a hydrophilic carrier by employing the fusion technique. Results: The powder SDs were subjected for solubility, Fourier transform infrared spectrometry (FTIR), Differential scanning calorimetry (DSC), in-vitro dissolution profile, Scanning electron microscopy (SEM), and X-ray diffraction (XRD) study. The FTIR spectral analysis showed no significant incompatibility between drug and carriers and confirmed the presence of SMZ. From XRD and DSC, SMZ indicated the amorphous form in solid dispersion with larger specific surface area, resulting in a better in-vitro rate of dissolution of the drug from solid dispersions than pure drug. However, SD of PX407 (SDSMFF8) indicated higher aqueous solubility than pure SMZ. Further, SDSMFF7 showed higher in-vitro drug release 96.45±0.3% within 60 minutes, and pure drug (18.54±0.8%). Conclusion: In conclusion, enhancing thesolubility and dissolution of SMZ using hydrophilic carriers by solid dispersion technique provides new strategies for broadening its potential clinical application.

2021 ◽  
Vol 16 ◽  
Balaji Maddiboyina ◽  
Ramya Krishna Nakkala ◽  
Prasanna Kumar Desu ◽  
Vikas Jhawat

Background: Nanoparticles made of silica are new materials that can be used in a wide range of drug delivery methods because they are biocompatible and biodegradable. Mesalamine, a classic water-soluble medication, remains loaded into the synthesized silica nanoparticle and is considered for sustained release proficiency. Precipitation approach using high surface area and pore volume tetraethyl orthosilicate yielded mesalamine-loaded silica nanoparticles. Methods: The drug-loaded nanoparticle was created and produced using two different techniques. Fourier transform infrared spectrometry, differential scanning calorimetry, X-ray powder diffraction, Brauer Emmett teller, scanning electron microscopy, particle size measurements, and dissolution investigations have all been used to analyse the substance in some way or another. Results: Because of the high surface area, well-known results like the complete silica nanoparticle created using method-2 remained mesoporous. The onset peak of the method-2 formulation's DSC was 182.27°c, and the offset peak was 192.14°c, consistent with the DSC results. The particle size range varies from 205-225nm. The results demonstrate that the uptake of the mesalamine by burst release it for 30 minutes initial, followed by sustained maintenance of dose even after 240 minutes. The results indicate that the loading process has an effect on the extent of loading. When silica nanoparticles were impregnated with mesalamine, the amount of the drug contained was significantly higher than when they were wetted. Conclusion: In addition, the XRD results show that both the pure mesalamine and the formulation did not show any polymorphic deviation.

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