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41.
Nikhil Bajpayee Thangavel Vijayakanth Sigal Rencus-Lazar Sneha Dasgupta Aamod V. Desai Rahul Jain Ehud Gazit Rajkumar Misra 《Angewandte Chemie (International ed. in English)》2023,62(6):e202214583
Flexible and biocompatible metal peptide frameworks ( MPFs) derived from short and ultra-short peptides have been explored for the storage of greenhouse gases, molecular recognition, and chiral transformations. In addition to short flexible peptides, peptides with specifically folded conformations have recently been utilized to fabricate a variety of metal helix frameworks ( MHFs ). The secondary structures of the peptides govern the structure-assembly relationship and thereby control the formation of three-dimensional (3D)- MHFs . Particularly, the hierarchical structural organization of peptide-based MHFs has not yet been discussed in detail. Here, we describe the recent progress of metal-driven folded peptide assembly to construct 3D porous structures for use in future energy storage, chiral recognition, and biomedical applications, which could be envisioned as an alternative to the conventional metal-organic frameworks (MOFs). 相似文献
42.
In water, N-methyl-4-(p-substituted benzoyl)pyridinium cations, BP-X, exist in equilibrium with their hydrated forms (gem-diols), whose concentrations depend on the para substituent (-X). In the presence of cucurbit[7]uril (CB[7]), the benzoyl group shows a preference for the CB[7] cavity, and the ketone to gem-diol equilibrium is shifted toward the keto form, meaning that the stabilization realized through hydrophobic interactions of the benzoyl group in the CB[7] cavity exceeds the hydrogen-bonding stabilization of the gem-diols in the aqueous environment. 相似文献
43.
Thangamani Rajkumar Chinnaswamy Thangavel Vijayakumar Palanichamy Sivasamy Bojja Sreedhar Charles A. Wilkie 《Journal of Thermal Analysis and Calorimetry》2010,100(2):651-660
Imparting thermal stability to polymethyl methacrylate (PMMA) without affecting its optical clarity is attempted by incorporating
HET acid based oligoesters. Pure PMMA and PMMA containing five and 20 wt% of four different oligoesters are separately prepared
using bulk polymerization. The thermal properties of the materials studied using DSC, TG, TG–FTIR and Pyr–GC–MS are presented.
The main volatile degradation products identified are CO, HCl, CO2, H2O, hexachlorocyclopentadiene, hexachloroendomethylene tetrahydrophthalic acid/anhydride and methyl methacrylate. A detailed
mechanism for the influence of the degradation products of HET acid based oligoesters on the thermal degradation of PMMA is
also presented. 相似文献
44.
Thangamani Rajkumar Palanichamy Sivasamy Bojja Sreedhar Chinnaswamy Thangavel Vijayakumar 《先进技术聚合物》2012,23(5):829-834
Optically clear poly(methyl methacrylate) (PMMA) blends with HET‐EG oligoester (synthesized by condensation of chlorendic acid with ethylene glycol) at six different compositions were prepared by bulk polymerization. The effect of HET‐EG in the PMMA matrix on the optical clarity of PMMA blend was measured using ultraviolet‐visible spectroscopic study. The thermal stability of PMMA blends was investigated using differential scanning calorimetric (DSC) and thermogravimetric (TG) analyses. The parameters to deduce the thermal stability of pure PMMA and PMMA blends were calculated from DSC and TG results. The thermal stability of PMMA was found to increase effectively by loading 5% of HET‐EG oligoester without marring optical clarity. The probable physical and chemical actions of HET‐EG oligoester on the thermal stability of PMMA are discussed. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
45.
Gnanasekar Pitchaimari Chinnaswamy Thangavel Vijayakumar 《Journal of Thermal Analysis and Calorimetry》2013,114(3):1351-1361
N-(4-Hydroxy phenyl)maleimide (HPMI) is functionalized with acryloyl, methacryloyl, allyl, propargyl and cyanate groups and the structures of the materials are characterized by FTIR, 1H NMR and 13C NMR. Thermal curing behaviours of the monomers and thermal stabilities of the polymers are studied using thermal analysis. Introduction of polymerizable groups shifts the curing exotherm to low temperatures, and the curing behaviour is dictated by the polymerizable substituent present in the aromatic ring. Polymer from acryloyl-functionalized monomer shows the highest thermal stability (402 °C), whereas the highest char value (49 % at 700 °C) is noted for the polymer obtained from propargyl-functionalized monomer. Polymers derived from functionalization of HPMI with acryloyl and methacryloyl showed better thermal stabilities. Thermosets formed by the thermal polymerization of HPMI functionalized with propargyl and cyanate groups showed higher char values at 700 °C in nitrogen atmosphere. 相似文献
46.
S. Kalyanaraman R. Thangavel R. Vettumperumal 《Journal of Sol-Gel Science and Technology》2013,65(2):238-242
Thin films of ZnO were grown by the sol–gel method using spin-coating technique on (0001) sapphire substrates. The effect of doping under Ar/H2 atmosphere on the structural and electrical properties of ZnO was investigated by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), I–V characterization, Hall effect and micro-photoluminescence. The films that were annealed at 600 °C in Ar/H2 (95/5) % atmosphere showed (002) a predominant orientation. The crystalline nature of 2 mol. % of Li doped films were better when compared to 1 mol. % of Li doped films. The incorporation of Li in ZnO lattice was confirmed by X-ray photoelectron spectroscopy, and micro-photoluminescence. Hall effect measurements and I–V characterization of the Li doped ZnO thin films exhibited a better p-type behavior. 相似文献
47.
48.
Subramani Selvi Arun Kannan John M. Jayaraj Thangavel Selvi Muthusamy Karthikeyan Chidambaram Prahalathan Natarajan Sampath Kannupal Srinivasan 《Journal of heterocyclic chemistry》2024,61(4):669-679
A series of 3-hydroxypyrazole derivatives have been synthesized by a base-promoted reaction of nitro-substituted donor–acceptor cyclopropanes with hydrazines. The synthesized compounds have been investigated for their ability to inhibit aquaporin 9 (AQP9) in rat Leydig cells (LC-540). The protein data bank structure for AQP9 was predicted using homology modeling; and the protein–ligand interaction for the synthesized hydroxyl pyrazole derivatives were analyzed using molecular modeling and docking studies. The results of in silico analyses showed that compound 5b had a higher binding affinity with AQP9 than other compounds. Further, in vitro studies conducted in LC-540 cells confirmed that compound 5b effectively inhibits AQP9. Hence, compound 5b may be used as an inhibitor in enhancing our understanding of AQP9 function, and in the treatment of several diseases. 相似文献
49.
S. Ramasubramanian M. Rajagoplan R. Thangavel J. Kumar 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(2):265-268
Elastic and Thermodynamical properties of Ti1-xZrxC have been investigated using LAPW + lo within the density-functional theory with the generalized gradient approximation.
We have studied the stability of the alloy Ti1-xZrxC as a function of Zr composition in rocksalt (B1) structure by calculating the elastic constants C11, C12 and C44 using the tetragonal and trigonal distortions. Mechanical properties such as Poisson ratio, bulk, shear and Young’s modulii
of Ti1-xZrxC are calculated. The Debye temperature and hardness are also computed for the first time to our knowledge for Ti1-xZrxC in various compositions. 相似文献
50.
R. Jothilakshmi V. Ramakrishnan R. Thangavel J. Kumar Andrei Sarua Martin Kuball 《Journal of Raman spectroscopy : JRS》2009,40(5):556-561
ZnO nanostructures have attracted great attention for possible applications in optoelectronic and spintronic devices. The electrical resistivity because of carriers can be improved by the introduction of Li ions, as Li is a possible dopant for achieving p‐type ZnO. We have carried out a comprehensive micro‐Raman scattering study of the phonons in 1% Li‐ and undoped ZnO needle crystals grown and annealed at 1073 K for 1 and 2 h under oxygen environment. Phonon mode of doped and undoped ZnO does not show any measurable shift for the doping concentration of 1%. As line width is related to point defect density, we find for both Li‐ and undoped ZnO crystals the crystallinity is improving towards the tip of the needle crystals. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献