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991.
Comparative studies on radiolytic degradation of deuterium labeled and unlabeled tributyl phosphates
Shikha Sharma Sunil K. Ghosh Devidas B. Naik Prem S. Dhami Joti N. Sharma 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(1):583-591
Deuterium labeled tributyl phosphates were synthesized and their solutions in n-dodecane have been investigated for γ-radiolytic degradation up to an absorbed dose of 2,000 kGy from a 60Co source. The performance was compared with undeuterated TBP. Radiolysis extent and pattern of formation of major degradation products, viz. dibutyl hydrogen phosphate and monobutyl dihydrogen phosphate were found to be very similar from deuterated or undeuterated samples. Extraction behavior for UO2 2+ and Pu(IV) was studied after the radiolysis, and the results showed similarity in extraction/stripping behavior for all labeled or unlabeled TBP samples. The isotope effect (k H/k D) observed is minimal in this γ-radiolytic degradation study. 相似文献
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Lok P. Singh Sriman K. BhattacharyyaRahul Kumar Geetika MishraUsha Sharma Garima SinghSaurabh Ahalawat 《Advances in colloid and interface science》2014
Recently, silica nanoparticles (SNPs) have drawn widespread attention due to their applications in many emerging areas because of their tailorable morphology. During the last decade, remarkable efforts have been made on the investigations for novel processing methodologies to prepare SNPs, resulting in better control of the size, shape, porosity and significant improvements in the physio-chemical properties. A number of techniques available for preparing SNPs namely, flame spray pyrolysis, chemical vapour deposition, micro-emulsion, ball milling, sol-gel etc. have resulted, a number of publications. Among these, preparation by sol-gel has been the focus of research as the synthesis is straightforward, scalable and controllable. Therefore, this review focuses on the recent progress in the field of synthesis of SNPs exhibiting ordered mesoporous structure, their distribution pattern, morphological attributes and applications. The mesoporous silica nanoparticles (MSNPs) with good dispersion, varying morphology, narrow size distribution and homogeneous porous structure have been successfully prepared using organic and inorganic templates. The soft template assisted synthesis using surfactants for obtaining desirable shapes, pores, morphology and mechanisms proposed has been reviewed. Apart from single template, double and mixed surfactants, electrolytes, polymers etc. as templates have also been intensively discussed. The influence of reaction conditions such as temperature, pH, concentration of reagents, drying techniques, solvents, precursor, aging time etc. have also been deliberated. These MSNPs are suitable for a variety of applications viz., in the drug delivery systems, high performance liquid chromatography (HPLC), biosensors, cosmetics as well as construction materials. The applications of these SNPs have also been briefly summarized. 相似文献
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Th(IV) has been titrated amperometrically at an applied e.m.f of −1.0 V (dropping mercury electrode vs. SCE) with diphenic acid (neutralized with sodium hydroxide). Th(IV) in the range 8.0–60.0 mg/100ml can be determined with an error of ±0.5%. A number of foreign ions including Ce(IV), Zr(IV), La(III), U(IV), U(VI) do not interfere even if present in excess but traces of Ti(IV) do. The method is rapid and selective and has been used for the determination of Th(IV) in monazite sand. 相似文献