The aim of the present study is to investigate the effect of the hydrolysis process on the properties of nanocrystalline cellulose (NCC) isolated from different precursors and the subsequent use of the extracted NCC for the reduction of graphene oxide (GO). The raw materials (almond and peanut shells) chosen for the isolation of cellulose were selected on the basis of their abundance and their poorly investigation in the production of NCC. Microcrystalline cellulose (MCC) was firstly extracted by alkali and bleaching treatments, then hydrolyzed under different processes to produce NCC polymorphs with structure I (NCC-I) and NCC structure II (NCC-II). The Fourier transform infrared spectroscopy, the X-ray diffraction (XRD) and the 13C NMR studies of the alkali and bleached products confirmed the formation of cellulose type I with high purity and good crystallinity, while scanning electron microscopy (SEM) showed micrometric fibers with lengths reaching 80 µm. Sulfuric acid treatment of these microfibers results in NCC type I or II, depending on the hydrolysis process. SEM of the NCC samples exhibited nanorods with diameter and aspect ratio in the range of 20–40 and 20–25 nm, respectively. Thermogravimetric analysis (TGA) of the MCC and NCC products indicated stable materials with a degradation temperature reaching 240 and 200 °C for MCC and NCC, respectively. The other part of our work concerns the use of the obtained cellulose nanocrystals (type II) for the preparation of reduced graphene oxide composite (NCC/RGO), to demonstrate the reducing properties of the isolated NCCII.

The first lanthanopolyoxometalate-supported bifunctional periodic mesoporous organosilica (BPMO) composite is here reported. The incorporation of decatunsgstoeuropate anions ([Eu(W5O18)2]9−) within the porous channels of an ethylene-bridged TMAPS-functionalized BPMO produced a luminescent material exhibiting a strong red emission under UV irradiation. Photoluminescence studies showed an efficient energy transfer process to the lanthanide emitting center in the material (antenna effect). A significant change in the coordination environment of Eu3+ ions was observed after its incorporation into the TMAPS-functionalized material. The possible reason for this is discussed within the paper.

Three iron(III) complexes with ligands derived from N-ethyl-N-(2-aminoethyl) salicylaldiminate (H, 1; 5-Br, 2; 3-OMe, 3 substituents at the phenyl group) were prepared and the X-ray crystal structures of 1 and 2 are reported. NMR studies of solutions of these complexes in DMSO allowed for investigation of their magnetic behaviour and paramagnetic relaxation contribution. The relaxivities measured ranged from 0.35 to 0.80 mM(-1) s(-1) for proton Larmor frequencies from 0.01 to 300 MHz, in agreement with those known for other iron(III) based contrast agents. Biological studies on colonic epithelial T-84 cell monolayers showed that the compounds exert toxic effects only at concentrations higher than 100 mu M while coincidently reducing colonic epithelial secretory function. These two features make these complexes good candidates for further development in order to be used as MRI contrast agents. (C) 2015 Elsevier B.V. All rights reserved.

Deuterium NMR was used to investigate the orientational order in a composite cellulosic formed by liquid crystalline acetoxypropylcellulose (A PC) and demented nematic 4'-penty1-4-cyanobiphenyl (5CB-4 alpha d(2)) with the per centage of 85% A PC by weight Three forms of the composite including electro spun microfibers, thin film and bulk samples were analyzed The NMR results initially suggest two distinct scenarios, one whet e the 503-alpha d(2), is confined to small droplets with dimensions smaller than the magnetic coherence length and the other where the 503-alpha d(2) molecules arc aligned with the A PC network chains Polarized optical microscopy (POW from thin film samples along with all the NMR results show the presence of 5CB-alpha d(2) droplets in the composite systems with a nematic wetting layer at the APC-5CB-alpha d(2) interface that experiences and order disorder transition driven by the polymer network N-I transition The characterization of the APC network I-N transition shows a pronounced subcritical behavior within a heterogeneity scenario

Deuterium and carbon-13 NMR spectroscopy were used to study both the high temperature uniaxial nematic and the low temperature biaxial nematic glass of a shape-persistent V-shaped mesogen. It was found that biaxial ordering determined in the domains of the latter has symmetry lower than D(2h) and is compatible with C(2h) symmetry or lower. In particular, elements of the ordering matrix including biaxial phase order parameters were determined from (2)H NMR at two temperatures, one just below the glass transition, and the other deep inside the biaxial glass, which allowed for the characterization of the dominant molecular motions at these temperatures. (13)C NMR magic angle spinning sideband patterns, collected both in the high temperature nematic phase and in the nematic glass, clearly show the difference between them in terms of the phase symmetry.