scholarly journals AC conductivity and dielectric behavior of poly (o-phenylenediamine)/TiO2 nanocomposites

2017 ◽  
Vol 5 (1) ◽  
pp. 29
Author(s):  
Archana S.
Keyword(s):  
Thermal Stability ◽  
Polymer Nanocomposites ◽  
Ac Conductivity ◽  
Oxidative Polymerization ◽  
Dielectric Behavior ◽  
High Thermal Stability ◽  
Spectral Techniques ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
The Stability

Poly (o-phenylenediamine) and their nanocomposites with TiO2 nanoparticles were synthesized using oxidative polymerization technique and the polymer nanocomposites were characterized using spectral techniques like FT-IR, UV-VIS spectroscopy and the morphology have been analyzed by XRD, SEM and TEM. The stability of the prepared polymer nanocomposites was studied using TGA, DTA and found to have high thermal stability. The study of ac conductivity, dielectric property revealed that the formed nanocomposites are semiconducting in nature and can be widely used in the field of energy storage and semiconductor devices, in diodes, batteries etc.

Study on Host-Guest Inclusion Complexation of a Drug in Cucurbit [6]uril

2018 ◽  
Vol 232 (2) ◽  
pp. 281-293 ◽  
Author(s):  
Kanak Roy ◽  
Subhadeep Saha ◽  
Biswajit Datta ◽  
Lovely Sarkar ◽  
Mahendra Nath Roy
Keyword(s):  
Surface Tension ◽  
Specific Conductivity ◽  
Inclusion Complexation ◽  
Conductivity Measurements ◽  
Saline Environment ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
The Stability ◽  
Ft Ir Spectroscopy

AbstractAssembly of pyridine-2-aldoxime drug with cucurbit [6]uril (CB[6]) has been investigated by1H-NMR and 2D-ROESY NMR, UV-Vis spectroscopy, FT-IR spectroscopy, surface tension and conductivity measurements in aqueous saline environment. The distinct cationic receptor feature and the cavity dimension of the CB[6] emphasize that the macro-cyclic host molecule remain as complex with the nerve stimulus drug molecule. The results obtained from surface tension and specific conductivity measurements suggest 1:1 inclusion complex formation between drug and CB[6]. The stability constant evaluated by UV-Vis spectroscopic approach is 2.21×105M−1at 298.15 K, which indicates that the complex is sufficiently stable at physiological temperature.

scholarly journals Synthesis, Characterization and Thermal Analysis of New Cu(II) Complexes with Hydrazide Ligands

2010 ◽  
Vol 7 (s1) ◽  
pp. S278-S282 ◽  
Author(s):  
Saber Rajaei ◽  
Shahriare Ghammamy ◽  
Kheyrollah Mehrani ◽  
Hajar Sahebalzamani
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Acetic Acid ◽  
Ir Spectroscopy ◽  
Coordination Mode ◽  
Azomethine Nitrogen ◽  
Excellent Thermal Stability ◽  
Spectral Techniques ◽  
Ft Ir ◽  
New Compounds

A number of new complexes have been synthesized by reaction of novel ligands acetic acid(4-methyl-benzylidene)hydrazide (L1) and acetic acid(naphthalen-1-ylmethylene)hydrazide (L2) with copper(II) nitrate. These new compounds were characterized by elemental analysis, TG, DTA, IR spectroscopy, UV spectral techniques. The changes observed between the FT-IR and UV-Vis spectra of the ligands and of the complexes allowed us to establish the coordination mode of the metal in complexes. The results suggest that the Schiff bases L1and L2coordinate as univalent anions with their bidentate N,O donors derived from the carbonyl and azomethine nitrogen. Also the probing of thermal analysis complexes can detect which complex has excellent thermal stability.

Preparation of Anion Modified Montmorillonite-Polystyrene Nanocomposite by Suspension Polymerization

2009 ◽  
Vol 87-88 ◽  
pp. 499-503
Author(s):  
Yi Wang ◽  
Hui Xia Feng ◽  
Jian Hui Qiu
Keyword(s):  
Thermal Stability ◽  
Anionic Surfactants ◽  
Suspension Polymerization ◽  
Layered Silicate ◽  
High Thermal Stability ◽  
X Ray Diffraction ◽  
X Ray ◽  
Modified Montmorillonite ◽  
Silicate Nanocomposites ◽  
Ft Ir

To ensure good compatibility between polymer and montmorillonite (MMT), three types organophilic-MMT were prepared and the influence of modifying agent style on the modification effect was studied. The results of X-ray diffraction(XRD) show that the modified reagents are all intercalated into the galleries of MMT, which are also proved by patterns of FT-IR and thermogravimetric analysis(TGA), and the spacing of MMT layers increases from 1.23 nm of the pristine MMT to 2.10nm, 3.52nm and 4.14nm for CTAB, SDS and DBS modified MMT respectively. The results also indicate that the d-spacing and exfoliation degree of anionic surfactants inserted MMT is bigger than that of the cationic surfactants treated MMT, which are usually used to preparation polymer layered silicate nanocomposites in literatures. So PS/SDS-MMT and PS/DBS-MMT nanocomposites were prepared by suspension polymerization. The structure of complex were characterized by XRD and no peak can be observed by the spectra, which suggest that the clay platelets have been exfoliated and dispersed in the PS matrix and the both complex are all have exfoliated structure. FT-IR spectrums analysis confirmed the existence of MMT which implied that the layers of silicate was distributing in composites. The results of TGA show that nanocomposites possess exceptionally high thermal stability and the DBS treated composite has higher thermal stability than that of SDS treated.

Development of Mo/γ-Al2O3-CeO2 Catalyst with High Thermal Stability by Modified Impregnation Method

2017 ◽  
Vol 888 ◽  
pp. 491-495
Author(s):  
Anita Ramli ◽  
Muhammad Farooq
Keyword(s):  
Thermal Stability ◽  
Supported Catalyst ◽  
High Thermal Stability ◽  
Binding Energies ◽  
Impregnation Method ◽  
Support Interaction ◽  
Characterization Techniques ◽  
Metal Support Interaction ◽  
Metal Support ◽  
The Stability

In the present studies, different characterization techniques have been utilized to evaluate the stability of catalysts prepared by modified impregnation method. The results indicated that strong metal-support (Mo-support) interaction existed in the γ-Al2O3-CeO2 supported catalyst with higher CeO2 loading as compared to the Mo/γ-Al2O3 catalyst. This suggested that the addition of CeO2 into the γ-Al2O3 enhanced the metal-support interaction, thus decreases the reducibility, depending on the CeO2 loading. Similarly, the catalyst with higher CeO2 loading exhibited lower Ce 3d and higher Mo 3d binding energies respectively, supporting the TPR results.

scholarly journals Bactericidal and In-Vitro Cytotoxic Efficacy of Silver Nanoparticles (Ag-NPs) Fabricated by Endophytic Actinomycetes and Their Use as Coating for the Textile Fabrics

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2082 ◽  
Author(s):  
Salem S. Salem ◽  
Ehab F. EL-Belely ◽  
Gniewko Niedbała ◽  
Maryam M. Alnoman ◽  
Saad El-Din Hassan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Inhibition Zone ◽  
In Vitro Cytotoxicity ◽  
Ag Nps ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
The Stability

An endophytic strain of Streptomyces antimycoticus L-1 was isolated from healthy medicinal plant leaves of Mentha longifolia L. and used for the green synthesis of silver nanoparticles (Ag-NPs), through the use of secreted enzymes and proteins. UV–vis spectroscopy, Fourier-transform infrared (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), and dynamic light scattering (DLS) analyses of the Ag-NPs were carried out. The XRD, TEM, and FT-IR analysis results demonstrated the successful biosynthesis of crystalline, spherical Ag-NPs with a particle size of 13–40 nm. Further, the stability of the Ag-NPs was assessed by detecting the surface Plasmon resonance (SPR) at 415 nm for one month or by measuring the NPs surface charge (−19.2 mV) by zeta potential analysis (ζ). The green-synthesized Ag-NPs exhibited broad-spectrum antibacterial activity at different concentrations (6.25–100 ppm) against the pathogens Staphylococcus aureus, Bacillus subtilis Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhimurium with a clear inhibition zone ranging from (9.5 ± 0.4) nm to (21.7 ± 1.0) mm. Furthermore, the green-synthesized Ag-NPs displayed high efficacy against the Caco-2 cancerous cell line (the half maximal inhibitory concentration (IC50) = 5.7 ± 0.2 ppm). With respect to antibacterial and in-vitro cytotoxicity analyses, the Ag-NPs concentration of 100 ppm was selected as a safe dose for loading onto cotton fabrics. The scanning electron microscopy connected with energy-dispersive X-ray spectroscopy (SEM-EDX) for the nano-finished fabrics showed the distribution of Ag-NPs as 2% of the total fabric elements. Moreover, the nano-finished fabrics exhibited more activity against pathogenic Gram-positive and Gram-negative bacteria, even after 10 washing cycles, indicating the stability of the treated fabrics.

Synthesis and solvatochromic of 3-(4-N-Pyridine -2-yl benzene sulfonamide azo)-1-nitroso naphthol and use it for determination of trace amount of Cobalt (II) as complex

2016 ◽  
Vol 5 (09) ◽  
pp. 4878
Author(s):  
Fatma A. Khazaal ◽  
Hussein J. Mohammed*
Keyword(s):  
Stability Constant ◽  
1H Nmr ◽  
Linear Correlation ◽  
Trace Amount ◽  
Honey Sample ◽  
Spectral Techniques ◽  
Azo Compound ◽  
Ft Ir ◽  
The Stability

The azo reagent 3- (4-N-Pyridine -2-yl benzene sulfonamide azo)-1-nitroso naphthol was synthesized and characterized by FT-IR, 1H-NMR and 13CNMR spectral techniques. The solvatochromism of the azo compound was studied by using different solvents. Spectrophotometric determination of cobalt (II) is based on the formation of a 2:1 complex with above reagent. The complex has λmax at (452) nm and Ԑmax of (2. 0567*104) L. mol-1. cm-1.A linear correlation (0.1- 3.5μg. ml-1) was found between absorbance at λmax and concentration. The effect of diverse ions on the determination of cobalt (II) to investigate the selectivity of the method were also studied. The stability constant of the product was (2. 68*108). The proposed method was successfully applied to the analysis of honey sample. 

Preparation and Properties of Waterborne Cationic Polyurethanes/Polypyrrole Conductive Composites

2013 ◽  
Vol 538 ◽  
pp. 129-132
Author(s):  
Hai Hua Wang ◽  
Jin Juan Hu ◽  
Yi Ding Shen ◽  
Gui Qiang Fei ◽  
Juan Zhang
Keyword(s):  
Thermal Stability ◽  
Oxidative Polymerization ◽  
Average Particle Size ◽  
Composite Films ◽  
Molar Ratio ◽  
Average Particle ◽  
Conductive Composites ◽  
Structure Morphology ◽  
Ft Ir

A series of waterborne cationic polyurethanes dispersions (CWPU) was prepared through prepolymerization method by reacting polyethylene glycol (PEG1000) and isophorone diisocyanate (IPDI) with N-methyl diethanol amine (MDEA) as chain extender. Then FeCl3 was employed as oxidant, therefore CWPU/polypyrrole (CWPU/PPy) conductive composite was prepared by in situ chemical oxidative polymerization of pyrrole (Py) in CWPU dispersions. Effects of molar ratio of FeCl3 to Py, Py concentration on the resistivity of the CWPU/PPy composite films were investigated. The structure, morphology and thermal stability were also characterized by Fourier infrared spectra (FT-IR), light scattering, TEM, and TGA. FT-IR demonstrated the presence of hydrogen-bonding interactions between CWPU and PPy. The average particle size of CWPU/PPy increased from 10.61nm to 30.29nm compared with pure PU, and corresponding size distribution decreased from 0.850 to 0.346. It was also found that CWPU/PPy displayed as spherical morphology, and no aggregation among particles was detected among particles. TGA certified CWPU/PPy was endowed with better thermal stability. In addition, conductivity stability of composites films was also studied. It was found that composite films not only displayed low resistivity but also improved conductivity stability.

scholarly journals Synthesis and Characterization of Polyaniline-Based Polymer Nanocomposites as Anti-Corrosion Coatings

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 653
Author(s):  
Francisco R. Rangel-Olivares ◽  
Elsa M. Arce-Estrada ◽  
Román Cabrera-Sierra
Keyword(s):  
Polymer Nanocomposites ◽  
Electrochemical Impedance ◽  
Oxidative Polymerization ◽  
Open Circuit ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
X Ray ◽  
Hydrochloric Acid Medium ◽  
Ft Ir

Polymer nanocomposites of polyaniline (PANI)-based metal oxides (SiO2, CeO2, and TiO2A) were synthesized by in situ chemical oxidative polymerization by rapid mixing in a hydrochloric acid medium to evaluate and compare their performance as anti-corrosion coatings on commercial 1018 steel in a 3.5% NaCl medium. The anti-corrosion coatings were developed by dispersing synthesized nanocomposites on an alkydalic resin (AR) for their subsequent electrochemical characterization. X-ray diffraction (XRD) analyses show that PANI has a certain degree of crystallinity in its structure. The incorporation of metal oxide (MO) nanoparticles (NPs) into the polymer matrix was confirmed by scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS) analyses, while the interaction of nanoparticles with PANI was proven by Fourier transform infrared (FT-IR) and ultraviolet-visible (UV-vis). Thermogravimetric analysis (TGA) reveals that nanoparticles infer greater resistance to the thermal decomposition of PANI. Finally, the use of open circuit potential (OCP) study, Tafel curves, and electrochemical impedance spectroscopy (EIS) showed that coatings made with TiO2A NPs exhibit the best anti-corrosion properties as compared to those synthesized with SiO2 and CeO2 NPs.

CRYSTAL GROWTH, THERMAL, OPTICAL, AND DIELECTRIC PROPERTIES OF L-LYSINE DOPED KDP CRYSTALS

2009 ◽  
Vol 23 (12) ◽  
pp. 1589-1602 ◽  
Author(s):  
KETAN D. PARIKH ◽  
DIPAK J. DAVE ◽  
MIHIR J. JOSHI
Keyword(s):  
Thermal Stability ◽  
Second Harmonic ◽  
Point Of View ◽  
Kinetic And Thermodynamic Parameters ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Shg Efficiency ◽  
Spectroscopy Studies ◽  
Kdp Crystals ◽  
Thermal Stability Of

Single crystals of pure and various amount of L-lysine doped KDP crystals were grown from aqueous solution. The doping of L-lysine was confirmed by CHN analysis and FT-IR spectroscopy. Powder XRD was carried out to assess the single phase nature of the samples. The effect of doping on thermal stability of the crystals was carried out by TGA and the kinetic and thermodynamic parameters of dehydration were evaluated. It was found that as the amount of doping of amino acid, L-lysine, increased the thermal stability of the grown crystals decreased. However, the second-harmonic generation (SHG) efficiency of Nd :YAG laser and UV-vis spectroscopy studies indicated that as the L-lysine doping increased in KDP crystals the SHG efficiency and optical transmission percentage increased. The dielectric constant and the dielectric loss of L-lysine doped KDP crystals are lower than the pure KDP crystals. Hence L-lysine doped KDP crystals are found to be more beneficial from an application point of view as compared to pure KDP crystals. The results are discussed.

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