02142nas a2200217 4500008004100000245011500041210006900156260000800225300000900233490000700242520135700249100002401606700002501630700002501655700002801680700002201708700001801730700002201748700002301770856013101793 2020 eng d00aCarbon supported size-controlled ru catalysts for selective levulinic acid hydrogenation into γ-valerolactone0 aCarbon supported sizecontrolled ru catalysts for selective levul cJAN a5-160 v133 a

Liquid phase levulinic acid hydrogenation into γ-valerolactone in 1,4-dioxane as a solvent (165°C, 20 bar) was studied over a range of Ru monometallic catalysts using mesoporous carbon material Sibunit as a support. In addition to the catalyst prepared by impregnation with RuCl3∙nH2O (0.1 M) followed by reduction in H2, size-controlled Ru(NPs)/Sibunit catalysts were synthesized by immobilization of polyvinylpyrrolidone (PVP) stabilized Ru nanoparticles (NPs) (dRu=2.4 nm). Сarbon supported colloidal Ru NPs were not studied earlier in levulinic acid hydrogenation. Activity of colloidal Ru(NPs)/Sibunit catalysts was found to be lower than that of impregnated Ru/Sibunit which could be attributed to hampering effect of PVP. However, colloidal Ru(NPs)/Sibunit purified by thermal treatment in air (180°C) followed by reduction in H2 (400°C) exhibited the same activity as impregnated one yielding 93% γ-valerolactone at 100% levulinic acid conversion. Applicability of supported PVP-assisted colloidal Ru NPs in hydrogenation of levulinic acid illustrates a potential to prepare more efficient catalysts for this reaction with a desired particle size. The catalysts were characterized by TEM, XRF, and N2 physisorption to compare their physical chemical properties.

1 aSimakova, Irina, L.1 aDemidova, Yuliya, S.1 aSimonov, Mikhail, N.1 aNiphadkar, Prashant, S.1 aBokade, Vijay, V.1 aDevi, Nandini1 aDhepe, Paresh, L.1 aMurzin, Dmitry, Yu uhttps://library.ncl.res.in/content/carbon-supported-size-controlled-ru-catalysts-selective-levulinic-acid-hydrogenation-%CE%B306595nas a2200181 4500008004100000245009800041210006900139260000900208300001200217490000700229520596300236100001706199700001506216700001906231700001806250700001906268856012606287 2021 eng d00aNanoparticles of biotite mica as Krishna Vajra Abhraka Bhasma: synthesis and characterization0 aNanoparticles of biotite mica as Krishna Vajra Abhraka Bhasma sy cJUN  a269-2820 v123 a

Background

Bio-inorganic nanoparticles or metal nanoparticles are used in medicine for diagnostic and treatment purposes. The nanomedicines from traditional Ayurvedic system are termed as bhasma. Rasashastra, the branch of inorganic medicines of Ayurveda, has documented monographs of metal-mineral bhasmas as potent drugs. However there is lack of scientific analytical data of the end products.

Objectives

Present study was aimed at finding out the morphological, structural, elemental and chemical composition of the Krishna vajra abhraka bhasma (KVB).

Materials and methods

Bhasma of KVB (Biotite Mica) was prepared in our laboratory using biotite mica sheets befitting selection criteria and carrying out further processes with strict SOPs as per AFI.

Results

The bhasma complied with the confirmatory tests from Rasashastra. The physical and physicochemical tests correlate with the results obtained by instrumental analytical methods. SEM revealed square shaped nanoparticles of mean size of 92.3 nm. EDAX showed presence of Si, Mg, O, Fe, Ca, Na, C, K and Al. XRD revealed the crystalline nature of bhasma with mixture of various individual oxides and spinel shape of the crystal. DLS showed that the nanoparticles are unimodal in nature. FTIR and NMR showed the organic functional groups obtained from cow milk and selected herbs, indicating unique bio-inorganic nature of the KVB.

 

1 aWele, Asmita1 aSourav, De1 aDalvi, Madhuri1 aDevi, Nandini1 aPandit, Vijaya uhttps://library.ncl.res.in/content/nanoparticles-biotite-mica-krishna-vajra-abhraka-bhasma-synthesis-and-characterization