scholarly journals Thermal and Photoresponsive Studies of Starch Modified with 2-(5-(4-Dimethylamino-benzylidine)-4-oxo-2-thioxo-thiazolidin-3-yl)acetic Acid

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Ambily Chandran ◽  
Sunny Kuriakose ◽  
Tessymol Mathew
Keyword(s):  
Acetic Acid ◽  
Light Absorption ◽  
Fluorescence Emission ◽  
Hydroxyl Group ◽  
Spectroscopic Methods ◽  
Polymeric System ◽  
System 2 ◽  
Ft Ir ◽  
Uv Visible ◽  
Thermal Stability Of

The present study describes the synthesis of a chromophoric system 2-(5-(4-dimethylamino-benzylidin)-4-oxo-2-thioxo-thiazolidin-3-yl)acetic acid and its incorporation into starch through esterification of the hydroxyl group by the free carboxyl function of the chromophoric system by DCC coupling. The products were characterized by UV-visible, fluorescence, FT-IR, and NMR spectroscopic methods. The newly developed system was subjected to photoresponsive studies such as light absorption, light stabilization and fluorescence emission. The free chromophoric system and the coupled product were also subjected to thermal analysis. The results show that modification enhances the light absorption and light fastening properties of the chromophoric system. Thermal stability of the polymeric system greatly enhances on attaching the chromophoric system. In view of these results the newly developed system is proposed as a nature friendly, green, and photoactive product which could find application in dyes, inks, paints, and so forth.

scholarly journals Polymerization of Ethylene Glycol Dimethacrylate (EGDM), Using An Algerian Clay as Eco-catalyst (Maghnite-H+ and Maghnite-Na+)

2020 ◽  
Vol 15 (1) ◽  
pp. 221-230 ◽  
Author(s):  
Sara Haoue ◽  
Hodhaifa Derdar ◽  
Mohammed Belbachir ◽  
Amine Harrane
Keyword(s):  
Ethylene Glycol ◽  
Exchange Process ◽  
Ethylene Glycol Dimethacrylate ◽  
Glycol Dimethacrylate ◽  
Green Catalyst ◽  
Ion Exchange Process ◽  
Ft Ir ◽  
Uv Visible ◽  
Thermal Stability Of ◽  
End Group

In this paper we have explored a novel and green method to synthesis and polymerize ethylene glycol dimethacrylate (EGDM). This technique consists on using Maghnite (Algerian clay) as a green catalyst to replace toxic catalysts. The Algerian clay has been modified using two ion exchange process to obtain Maghnite-H+ (proton exchanged process) and Maghnite-Na+ (sodium exchanged process). Synthesis experiments of EGDM and Poly (EGDM) are performed in bulk respecting the principles of green chemistry. The structure of the obtained monomer and the obtained polymer was confirmed by FT-IR, 1H-NMR and 13C-NMR, where the methacrylate end groups are clearly visible. The presence of unsaturated end group in the structure of monomer was confirmed by UV-Visible analysis. Thermogravimetric analysis (TGA) was used to study the thermal stability of these obtained products. Copyright © 2020 BCREC Group. All rights reserved 

UV/VIS Characterization and FT-IR Analysis of Harmattan Dust across Sub-Sahara Region of Africa

2021 ◽  
Vol 14 (1) ◽  
pp. 1-17
Keyword(s):  
Dust Particles ◽  
Hydroxyl Group ◽  
Trade Wind ◽  
North East ◽  
Out Of Plane ◽  
Ft Ir ◽  
Ir Analysis ◽  
Suspended Dust ◽  
Uv Visible ◽  
Light Absorbance

Abstract: The suspended dust particles that blow across Nigeria as a result of north-east trade wind emanating from the Sahara desert annually are locally referred to as Harmattan. Suspended dust samples were collected across ten different stations in Nigeria; namely: Maiduguri (11º49'N, 13º09'E), Potiskum (11º43'N, 11º02'E), Bauchi (10º17'N, 09º 48'E), Jos (9º55'N, 8º55'E), Lafia (08º49'N, 07º50'E), Abuja (09º09'N, 07º11'E), Minna (9º36'N, 06º35'E), Ilorin (8º36'N, 4º 35'E), Oyo (8º12'N, 3º42'E) and Iwo (7º63'N, 4º19'E) and analyzed using Fourier Transform Infrared (FT-IR) and UV-Visible spectroscopy. The quantitative, qualitative and optical characterization analyses were carried out on all the samples collected across all the stations considered, in order to obtain the functional groups and some elements present in the samples. The FT-IR spectra peaks show that the transmittance waveband from 3337.8 cm-1 to 3291.2 cm-1 corresponds to the Hydroxyl group, H-bonded OH stretch in plane and out of plane bonds for all the stations considered. These bonds represent the presence of transition metals and unsaturated bonds found in the samples, which include K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Mo, As, Zr, Pb, V, Sr, Cr and Ce. The samples collected across all stations have maximum UV absorbance peaks at around 210 nm waveband and weak visible light absorbance peaks (orange – red spectra) around 620 nm and 700 nm. The study concluded that the transmittance waveband, the waveband absorbance peaks and the elemental composition of the dust samples analyzed vary from station to station. This study will however recommend that further study be made for the purpose of environmental awareness. Keywords: Harmattan, Particles, FT-IR, UV, Dust.

scholarly journals Inhibition of Switch-on Fluorescence of Fluorochrome on Loading TiO2 with Gold

2021 ◽  
Author(s):  
Dhanalekshmi K.I ◽  
Chengchen Jiang ◽  
Jayamoorthy K ◽  
Magesan P ◽  
Oguejiofo T. Ujam ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Molecular Electrostatic Potential ◽  
Fluorescent Sensor ◽  
Fluorescence Emission ◽  
Azomethine Nitrogen ◽  
Binding Interaction ◽  
Spectral Techniques ◽  
Strong Adsorption ◽  
Ft Ir ◽  
Uv Visible

Abstract Gold loaded TiO2 nanoparticles have been synthesized and characterized by powder XRD, HR-TEM, and EDX analysis. The binding interaction of fluorescent sensor 5-amino-2-mercaptobenzimidazole (fluorochrome) with TiO2 and gold loaded TiO2 nanoparticles has been discussed herein. The interaction of fluorochrome with TiO2 and gold loaded TiO2 nanoparticles has been studied by UV-visible, fluorescence, and FT-IR spectral techniques. The fluorescence emission occurs at 421 nm and this has been selectively enhanced by TiO2 nano semiconductor. This technique is sensitive to detect and estimate TiO2 nano semiconductor at a micromolar level. This switch-on fluorescence is suppressed when it is loaded with gold. The strong adsorption of fluorochrome over the surface of nano semiconductor results in the electron transfer between fluorochrome and nano semiconductor. Further, the binding site of nano semiconductor with fluorochrome has been studied theoretically by using the molecular electrostatic potential (MEP). The results show higher electron density at the azomethine nitrogen atom.

Synthesis and Characterization of Acrylamide Based Benzoxazine

2012 ◽  
Vol 621 ◽  
pp. 11-16
Author(s):  
Erigene Bakangura ◽  
Zhong Yu Luo ◽  
Guang Kai Wang ◽  
Yang Bin ◽  
Yan Ping Yue ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Phenolic Resin ◽  
Curing Temperature ◽  
Hydroxyl Group ◽  
Synthesis And Characterization ◽  
Oxazine Ring ◽  
Ft Ir ◽  
Thermal Stability Of ◽  
Direct Condensation

Novel benzoxazine monomers, acrylamide based benzoxazine, have been prepared from direct condensation of phenols with acrylamide and formaldehyde. 1H NMR and FT-IR, DSC and TGA were used to analysis the structure, compositions and investigate the curing behaviour and thermal stability, respectively. Solvent effects were studied. Solventless method is good for higher formation ratio of benzoxazine to the corresponding phenolic resin. The ratio for P-AA is 36.4% by solventless method, while it’s about 26% by toluene solvent; and 44% and 20% for B-AA, respectively. The monomers mixtures exhibit curing temperature (ca.187oC) without catalysts lower than their related allyl-benzoxazine. The FT-IR of different curing temperature shows the disappearance of double bond absorption at 1668 cm-1 and oxazine ring at 1232 cm-1 and appearance of hydroxyl group at 3446 cm-1. Thermal stability of cured benzoxazine show good char residues compared with traditional benzoxazine of aniline.

Synthesis, Characterization and Thermal Study of Some Transition Metal Complexes Derived from Quinoxaline-2,3-Dione

2018 ◽  
pp. 209
Author(s):  
Taghreed M. Musa ◽  
Mahmoud Najim A.Al-jibouri ◽  
Bayader Fadhil Abbas
Keyword(s):  
Thermal Stability ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Dsc Analysis ◽  
Visible Spectra ◽  
Elemental Analyses ◽  
Ft Ir ◽  
Uv Visible ◽  
Thermal Stability Of

   The present paper describes the synthesis and structural studies of new transition metal complexes of cobalt(II), nickel(II), copper(II) and cadmium(II) with two bi dentate ligands derived from quinoxaline-2,3-dione. The two ligands were fully identified by elemental analyses, FT-IR, NMR and UV-Visible spectra. The metal complexes of  Co(II), Ni(II), Cu(II) and Cd(II) were isolated in the solid state after reactions of their metal chlorides with the ligands in 2:1 mole ratio. The isolated solid metal complexes were characterized with the help of elemental analyses, NMR, FT-IR and UV-Visible spectra. As well as the thermal stability of the coordinated quinoxaline polymers were tested by TG-DSC analysis and it is found that cleavage of terminal moiety was investigated, the strong coordinated bonds between oxygen donor atoms in L1 while nitrogen donor atoms of quinoxaline ring in the L2 with the metal ions. Furthermore, the thermal stability of cobalt(II), nickel(II), copper(II) and Cd(II) complexes were screened by TG-DSC analysis and the results helped us in the investigation of the proposed structure of the prepared complexes in the formula [M(L)2Cl2].XH2O and [Cd(L)2]Cl2 where L= L1 and L2  ligands derived from quinoxaline-2,3-dione.  

scholarly journals Synthesis, characterization and antibacterial studies of Mn(II) and Co(II) complexes of an ionic liquid tagged Schiff base

2016 ◽  
Vol 81 (10) ◽  
pp. 1151-1159 ◽  
Author(s):  
Sanjoy Saha ◽  
Ananya Das ◽  
Kaushik Acharjee ◽  
Biswajit Sinha
Keyword(s):  
Escherichia Coli ◽  
Ionic Liquid ◽  
Schiff Base ◽  
Antibacterial Activities ◽  
Spectroscopic Methods ◽  
Tetrahedral Geometry ◽  
Antibacterial Studies ◽  
Ft Ir ◽  
Uv Visible

Mn(II) and Co(II) complexes of an ionic liquid-based Schiff base, 1-{2-(2-hydroxybenzylideneamino)ethyl}-3-methylimidazolium bromide, were synthesized and characterized by various analytical and spectroscopic methods such as elemental analysis, UV-Visible, FT-IR, 1H NMR, ESI-MS and magnetic susceptibility measurement. These studies indicated tetrahedral geometry for the complexes. The Schiff base ligand and its complexes were tested for in vitro antibacterial activities to assess their inhibiting potentials against Escherichia coli and Lactobacillus sp.

scholarly journals Synthesis, Characterization and Properties of MgB2 Doped Polyaniline

2017 ◽  
Vol 4 (1) ◽  
pp. 1-9
Author(s):  
Dr Shumaila ◽  
M. Zulfequar ◽  
M. Husain
Keyword(s):  
Conduction Mechanism ◽  
Oxidative Polymerization ◽  
Salt Form ◽  
Absorption Mechanism ◽  
Doped Polymers ◽  
Ft Ir ◽  
Doped Polyaniline ◽  
Uv Visible ◽  
Polymerization Method ◽  
Thermal Stability Of

Present paper reports novel synthesis of MgB2 doped Polyaniline (PAni). PAni is synthesized through oxidative polymerization method using Ammonium Peroxodisulphate and doped by different compositions of MgB2. The DC conductivity of undoped and doped polymers is measured in the temperature range of 300 – 400 K and is found to increase with temperature. An increase in conductivity by five orders of magnitude has been observed after doping. Conduction mechanism was also studied in all of the samples. FT-IR (Fourier Transform Infrared spectroscopy) and ultraviolet (UV)-Visible studies confirm the occurrence of PAni in conducting emeraldine salt form in the composites. The optical studies signify that absorption mechanism is due to direct allowed transition and the band gap decrease after doping. Thermal stability of all the composites has been explained on the basis of variation in Tc–Tg and ∆Hc by using DSC (Differential Scanning Calorimetery) measurements.

Investigation of Some Characterizations of Black TiO\(_2\) Nanotubes Via Spectroscopic Methods

2019 ◽  
Vol 29 (2) ◽  
pp. 189 ◽  
Author(s):  
Tho Truong Nguyen ◽  
Thi Minh Cao ◽  
Hieu Van Le ◽  
Viet Van Pham
Keyword(s):  
Water Splitting ◽  
Oxygen Vacancies ◽  
Light Response ◽  
Nanotube Arrays ◽  
Spectroscopic Methods ◽  
Visible Light Response ◽  
Uv Visible ◽  
Visible Reflectance ◽  
Splitting Effect ◽  
Anodization Method

The black TiO\(_2\) with substantial Ti\(^3+\) and oxygen vacancies exhibit an excellent photoelectrochemical water-splitting performance due to the improved charge transport the extended visible light response. In this study, black TiO\(_2\) nanotube arrays synthesized by the anodization method, and then, they have been investigated some characterizations by spectroscopic methods such as UV-visible reflectance (UV-vis DRS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and photoluminescence spectrum. The results showed that some highlighted properties of the black TiO2 nanotube arrays and they could apply for water-splitting effect.

Spectral Investigation on the Growth and Characterization of NLO Crystals of Thiourea Succinic Acid Single Crystal.

2015 ◽  
Vol 2 (2) ◽  
pp. 70-73
Author(s):  
Kannan.P ◽  
Thambidurai.S ◽  
Suresh.N
Keyword(s):  
Single Crystal ◽  
Succinic Acid ◽  
Slow Evaporation Technique ◽  
Absorption Studies ◽  
Dta Analysis ◽  
Evaporation Technique ◽  
Ft Ir ◽  
Ir Spectroscopic ◽  
Thermal Stability Of

Growth of optically transparent single crystals of thiourea succinic acid (TUSA) was grown successfully from aqueous solution by slow evaporation technique. The crystal structure was elucidated using the single crystal XRD. The various functional groups and the modes of vibrations were identified by FT-IR spectroscopic analysis. The optical absorption studies indicate that the optical transparency window is quite wide making its suitable for NLO applications. Thermal stability of the crown crystal carried out by TGA-DTA analysis.

scholarly journals Effect of methyl substituent on the solubility of 1,4-benzoquinone derivatives in n-octanol/water system

2020 ◽  
Vol 23 (5) ◽  
pp. 142-146
Author(s):  
Siti Mariyah Ulfa ◽  
Fath Dwisari ◽  
Ade Cintyia Sally ◽  
Mohammad Farid Rahman
Keyword(s):  
Shake Flask ◽  
Water System ◽  
Insertion Reaction ◽  
Log P ◽  
Methyl Substituent ◽  
Promising Candidate ◽  
New Drug ◽  
Alkyl Bromides ◽  
Ft Ir ◽  
Uv Visible

The solubility of the compound is a crucial task for new drug design. Quinone is a promising candidate to develop as a new drug. In this research, the synthesis of 1,4-benzoquinone derivatives, that is, 2-(5-bromoamyl)-3,5-dimethyl-1,4-benzoquinone (2a) and 2-(5-bromoamyl)-5-methyl-1,4-benzoquinone (2b) were carried out by decarboxylation and insertion reaction of alkyl bromides. The product 2a and 2b are purified using SiO2 gel column chromatography and analyzed by UV-Visible, FT-IR, and NMR. The yield of 2a is 13.75%, and 2b is 4.04%. The solubility of 2a and 2b, expressed by log P, is measured in the n-octanol/water (3:7 (v/v)) system by the shake flask method. The log P of 2a and 2b are 2.99 and 1.36, respectively. It is showed that the log P of 2a is higher compared to 2b. The presence of two methyl substituents on the quinone ring of 2a supports the increase of hydrophobicity of the compound in the n-octanol/water system.

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