RESUMO
These data and analyses support the research article "Production of cellulose nanoparticles from blue agave waste treated with environmentally friendly processes" Robles et al. [1]. The data and analyses presented here include fitted curves for selected carbons of the 13C CP-MAS NMR analysis; SEM images of the raw and bleached fibers, graphics with chemical composition and visual images of the fibers throughout the process.
RESUMO
Tequila elaboration leaves two main byproducts that are undervalued (bagasse and leaves). Organosolv pulping and Total Chlorine Free bleaching were integrated to obtain cellulose fibers from agricultural waste which consisted of blue agave bagasse and leaf fibers; together they represent a green process which valorizes biomass waste. The obtained celluloses were characterized by FT-IR, colorimetry, and SEM and their extraction yields were evaluated. These celluloses were used to produce cellulose nanocrystals and cellulose nanofibers. First, an acid hydrolysis was performed in a sonication bath to induce cavitation during the reaction to produce cellulose nanocrystals. Then a high-pressure homogenization was selected to produce cellulose nanofibers. These nanocelluloses were characterized by powder XRD, Nanosizer, zeta potential, NMR, and electronic microscopy. Results showed that cellulose from organosolv pulps bleached with TCF bleaching is suitable for nanocellulose production. Moreover, the use of a new step to separate cellulose nanocrystals resulted in yields almost doubling traditional yields, while the rest of the properties remained within the expected.
RESUMO
The dependences on energy of the resonant soft x-ray Bragg diffraction intensities in DyB(2)C(2) for the (00½) reflection at the Dy M(4,5) edges have been calculated with an atomic multiplet Hamiltonian including the effect of the crystal field and introducing an intra-atomic quadrupolar interaction between the 3d core and 4f valence shell. These calculations are compared with experimental results (Mulders et al 2006 J. Phys.: Condens. Matter 18 11195) for the antiferroquadrupolar and antiferromagnetic phases of DyB(2)C(2). We reproduce all the features appearing in the (00½) reflection energy profile in the antiferroquadrupolar ordered phase, and we reproduce the behaviour of the resonant x-ray scattering intensity at different energies in the vicinity of the Dy M(5) edge when the temperature is lowered within the antiferromagnetic phase. These calculations show that a detailed description of the energy dependences of resonant x-ray scattering signals at the M edges in 4f and 5f systems with multipolar ordering may require the inclusion of an aspherical intra-atomic Coulomb interaction.
RESUMO
A systematic analysis of resonant x-ray Bragg diffraction data for UPd(3), with signal enhancement at the U M(IV) edge, including possible structural phase transitions leads to a new determination of the space groups of the material in the phases between T(0)=7.8 K and T(+1)=6.9 K, as P 222(1), and between T(-1)=6.7 K and T(2)=4.4 K, as P2(1). In addition, the quadrupolar order parameters, {Q(ab)}, inferred from diffraction data for the phase between T(-1) and T(2), are {Q(xz)} and {Q(yz)} at the (103) Bragg reflection and {Q(xy)} at the (104) reflection.