01672nas a2200229   4500008004100000022001400041245011000055210006900165260009900234300001200333490000800345520083000353653002301183653001401206653000801220653001501228653001801243653000801261100002501269700002301294856012501317       2014                        eng d  a0144-861700aFunctionalized celluloses and their nanoparticles: morphology, thermal properties, and solubility studies0 aFunctionalized celluloses and their nanoparticles morphology the  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcAPR  a135-1420 v1043 a<p>Agricultural residues derived cellulose was used to synthesize a new series of carboxy functionalized cellulosic nanoparticles (quasi-spherical shaped, 13.2-21.5% carboxyl content) and macro-sized 6-carboxycelluloses (long-fibril shaped, 1.7-22% carboxyl content). The DP (50-70) and yield (upto 46%) of nanoparticles were manipulated by controlling the reaction temperature and time. TGA/DTG thermographs of the carboxycelluloses gave thermostability data and co-related well with the residual crystalline, amorphous, and anhydroglucuronic acid content. The particle shape and size had no effect on the thermal stability. Some derivatives were fully or partially soluble in aqueous alkali and non-aqueous solvents, which can lead to increased versatility of these polymers. (C) 2014 Elsevier Ltd. All rights reserved.</p>10a6-Carboxycellulose10acellulose10aDTG10aMorphology10aNanoparticles10aTGA1 aSharma, Priyanka, R.1 aVarma, Anjanikumar  uhttps://library.ncl.res.in/content/functionalized-celluloses-and-their-nanoparticles-morphology-thermal-properties-and-002266nas a2200229   4500008004100000022001400041245015400055210006900209260009900278300001200377490000800389520136000397653002101757653001401778653001801792653000801810653001001818100002501828700003501853700002301888856012501911       2014                        eng d  a0144-861700aSupramolecular transitions in native cellulose-I during progressive oxidation reaction leading to quasi-spherical nanoparticles of 6-carboxycellulose0 aSupramolecular transitions in native celluloseI during progressi  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcNOV  a615-6230 v1133 a<p>Cellulose-I swells considerably in phosphoric acid, and converts to amorphous cellulose via a cellulose-II transition state. Controlled oxidation of cellulose-I to 6-carboxycellulose (6CC) using HNO3-H3PO4-NaNO2 oxidation system led to the selective production of 6CC's of varying carboxyl contents (1.7-22%) as well as various shapes and sizes (macro-sized fibrils of several micron length and/or spherical nanoparticles of 25-35 nm), depending on the reaction conditions. 6CC's having less than 14% carboxyl content were largely in cellulose-II form (WAXRD values in-between cellulose I and cellulose II), whereas at 14-22% the 6CC's were largely amorphous; only trace crystallinity was observed at 19% and 22% carboxyl 6CC. Spherical nanoparticles retained a high degree of crystallinity having cellulose-I structure, whereas the macro-sized fibrils were largely converted to cellulose-II structure. Analysis by WAXRD as well as by CP-MAS C-13 NMR studies gave similar conclusions. Reduced molecular weight with progressive oxidation, including presence of oligomers, was also evident from an increase in the reducing-end carbon peak at similar to 92 ppm. For high oxidation levels (&gt;14%) the NMR 92-96 ppm peaks disappeared on extracting with dilute alkali, due to soluble oligomers being removed. (C) 2014 Elsevier Ltd. All rights reserved.</p>10aCarboxycellulose10acellulose10aNanoparticles10aNMR10aWAXRD1 aSharma, Priyanka, R.1 aRajamohanan, Pattuparambil, R.1 aVarma, Anjanikumar  uhttps://library.ncl.res.in/content/supramolecular-transitions-native-cellulose-i-during-progressive-oxidation-reaction-0