Modification of Chitin with Kraft Lignin and Development of New Biosorbents for Removal of Cadmium(II) and Nickel(II) Ions

Novel, functional materials based on chitin of marine origin and lignin were prepared. The synthesized materials were subjected to physicochemical, dispersive-morphological and electrokinetic analysis. The results confirm the effectiveness of the proposed method of synthesis of functional chitin/lignin materials. Mechanism of chitin modification by lignin is based on formation of hydrogen bonds between chitin and lignin. Additionally, the chitin/lignin materials were studied from the perspective of waste water treatment. The synthetic method presented in this work shows an attractive and facile route for producing low-cost chitin/lignin biosorbents with high efficiency of nickel and cadmium adsorption (88.0% and 98.4%, respectively). The discovery of this facile method of synthesis of functional chitin/lignin materials will also have a significant impact on the problematic issue of the utilization of chitinous waste from the seafood industry, as well as lignin by-products from the pulp and paper industry

Isolation and identification of chitin from heavy mineralized skeleton of Suberea clavata (Verongida: Demospongiae: Porifera) marine demosponge

WOS: 000412959500037PubMed: 28185932Since the discovery of chitin in skeletal structures of sponges (Porifera) in 2007, studies on search of novel species which possess this structural aminopolysaccharide continue up today. The most potential source of chitin is suggested to be localized in the four families of sponges related to the order Verongida (Demospongiae) which nevertheless require further clarification. Here, we report for the first time the isolation and identification of alpha-chitin from the Suberea clavata demosponge (Aplysinidae: Verongida). Raman spectroscopy, Calcofluor White staining, chitinase test and ESI-MS techniques were used to identify chitin. We suggest that the presence of chitin within fibrous skeletons of diverse species of Verongida order, and, especially in all species of the Aplysinidae family, may be useful for the identification of novel, previously unidentified marine demosponges. (C) 2017 Elsevier B.V. All rights reserved.DFG (Germany) [EH 394-3]; PUT research grant (Poland) [03/32/DSPB/0706/2017]This work was supported by DFG Grant EH 394-3 (Germany) and PUT research grant 03/32/DSPB/0706/2017 (Poland). The authors thank Prof. Dr. Yixin Zhang for the use of the ESI-MS instrument and Rob van Soest for his support and comments

Photoluminescence of HgCdTe nanostructures grown by molecular beam epitaxy on GaAs

AbstractPhotoluminescence (PL) of HgCdTe-based hetero-epitaxial nanostructures with 50 to 1100 nm-wide potential wells was studied. The nanostructures were grown by molecular beam epitaxy on GaAs substrates. A strong degree of alloy disorder was found in the material, which led to the broadening of the PL spectra and a considerable Stokes shift that could be traced up to temperature T∼230 K. Annealing of the structures improved the ordering and led to the increase in the PL intensity. A remarkable feature of the PL was an unexpectedly small decrease of its intensity with temperature increasing from 84 to 300 K. This effect can be related to localization of carriers at potential fluctuations and to the specific character of Auger-type processes in HgCdTe-based nanostructures.</jats:p

Isolation and identification of chitin in three-dimensional skeleton of Aplysina fistularis marine sponge

The recent discovery of chitin within skeletons of numerous marine and freshwater sponges (Porifera) stimulates further experiments to identify this structural aminopolysaccharide in new species of these aquatical animals. Aplysina fistularis (Verongida: Demospongiae: Porifera) is well known to produce biologically active bromotyrosines. Here, we present a detailed study of the structural and physico-chemical properties of the three-dimensional skeletal scaffolds of this sponge. Calcofluor white staining, Raman and IR spectroscopy, ESI-MS as well as chitinase digestion test were applied in order to unequivocally prove the first discovery of α-chitin in skeleton of A. fistularis

Solvothermal synthesis of hydrophobic chitin–polyhedral oligomeric silsesquioxane (POSS) nanocomposites

Chitinous scaffolds isolated from the skeleton of marine sponge Aplysina cauliformis were used as a template for the deposition of polyhedral oligomeric silsesquioxanes (POSS). These chitin–POSS based composites with hydrophobic properties were prepared for the first time using solvothermal synthesis (pH 3, temp 80°C), and were thoroughly characterized. The resulting material was studied using scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and thermogravimetry. A mechanism for the chitin-POSS interaction after exposure to these solvothermal conditions is proposed and discussed

Extreme biomimetic approach for developing novel chitin-GeO2GeO_{2} nanocomposites with photoluminescent properties

This work presents an extreme biomimetics route for the creation of nanostructured biocomposites utilizing a chitinous template of poriferan origin. The specific thermal stability of the nanostructured chitinous template allowed for the formation under hydrothermal conditions of a novel germanium oxide-chitin composite with a defined nanoscale structure. Using a variety of analytical techniques (FTIR, Raman, energy dispersive X-ray (EDX), near-edge X-ray absorption fine structure (NEXAFS), and photoluminescence (PL) spectroscopy, EDS-mapping, selected area for the electron diffraction pattern (SAEDP), and transmission electron microscopy (TEM)), we showed that this bioorganic scaffold induces the growth of $GeO_{2}$ nanocrystals with a narrow (150–300 nm) size distribution and predominantly hexagonal phase, demonstrating the chitin template’s control over the crystal morphology. The formed $GeO_{2}$–chitin composite showed several specific physical properties, such as a striking enhancement in photoluminescence exceeding values previously reported in $GeO_{2}$-based biomaterials. These data demonstrate the potential of extreme biomimetics for developing new-generation nanostructured materials