Design, Structural Characteristic and Antibacterial Performance of Silver-Containing Cotton Fiber Nanocomposite.

In the present study, cotton fiber was treated with phosphorus trichloride in the presence of oxygen. As a result of the subsequent hydrolysis of modified cotton fibers, phosphorus-containing fragments with acidic groups and chlorine atoms were introduced onto their surface. Afterward, silver-containing composites based on raw and modified cotton fibers were prepared using the chemical reduction method. The obtained samples were characterized in detail by Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, X-ray powder diffraction, as well as by thermogravimetric analysis, scanning electron microscopy, and energy-dispersive X-ray analysis. A comparative bioassay experiment of four samples for gram-negative (Escherichia coli) bacteria, gram-positive (Staphylococcus aureus) bacteria, and the fungus Candida albicans was carried out. These results showed the predominant antibacterial activity of the phosphorylated sample and the composite based on it. Thus, the development of these antibacterial cotton fibers using readily available reagents under relatively mild conditions could be used as potential industrial applications for the production of everyday medical textiles.

Cobalt chromium-layered double hydroxide, α- and ß- Co(OH)2 and amorphous Cr(OH)3: synthesis, modification and characterization.

Cobalt-chromium layered double hydroxide (CoCr LDH), α- and ß- Co(OH)2 and amorphous Cr(OH)3 have been synthesized under different reaction conditions. The obtained CoCr LDH was modified by stearic acid (SA) and sodium stearate (SS). The obtained samples have been characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), Ultraviolet-visible- (UV-Vis), Fourier transform infrared- (FTIR) and Energy-dispersive X-ray- (EDX) spectroscopy. The influence of reaction conditions on product composition, structural and optical properties of the samples have been discussed in detail. The basal spacing of CoCr-LDH increased from 7.366 Å to 7.428 Å and 25.214Å after the intercalation by stearic acid and sodium stearate, respectively. The average particles size by SEM analyze was estimated to be approximately 100-150 nm and 30-50 nm for CoCr-LDH0.6M(90°C) and CoCr-LDH0.6M(90°C)/SS nanostructures, respectively. Mixed hydroxides like α- and ß- Co(OH)2 have been obtained along with LDH at lower pH value (pH ∼ 7). The number of diffraction peaks corresponding to ß-Co(OH)2 has increased with relatively decreasing of Co2+ ions in the reaction medium. At high chromium concentrations (Co2+:Cr3+ = 1:3 and 1:5), amorphous Cr(OH)3 were formed in the experiment.

Fabrication of Functional Carbon/Magnetic Nanocomposites as A Promising Model of Utilization of Used Crosslinked Polymers.

The utilization of used crosslinked functional polymers (CFP) applied as sorbents or ion-exchangers is a great challenge arising from the need to protect the environment. In this paper we report a very promising way of obtaining carbon/magnetic composites based on metal (Co2+; Ni2+; Fe3+) derivatives of butadiene rubber-based phosphorus-containing polymer, which were treated as the model used CFP. We proposed a facile one-step thermal degradation approach to transform used CFP into carbon/magnetic composites (CMC). The obtained CMCs contained a mixture of metal phosphates and metal phosphides that exhibited strong magnetic properties due to the presence of nanosized metal derivatives with diameters of 100⁻140 nm. Structural and morphological changes of CFP and CMC after thermal degradation were investigated by the FTIR technique, X-ray Diffraction analysis, Scanning Electron Microscope, and Atomic Force Microscope⁻Magnetic Force Microscope. Moreover, thermal degradation kinetics parameters were determined to optimize the efficiency of the process.

Covalently Modified Graphene Oxide and Polymer of Intrinsic Microporosity (PIM-1) in Mixed Matrix Thin-Film Composite Membranes.

In this study, mixed matrix membranes (MMMs) consisting of graphene oxide (GO) and functionalized graphene oxide (FGO) incorporated in a polymer of intrinsic microporosity (PIM-1) serving as a polymer matrix have been fabricated by dip-coating method, and their single gas transport properties were investigated. Successfully surface-modified GOs were characterized by Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The effect of FGO loading on MMM morphology and performance was investigated by varying the FGO content in polymer matrix from 9 to 84 wt.%. Use of high FGO content in the polymer matrix helped to reveal difference in interaction of functionalized fillers with PIM-1 and even to discuss the change of FGO stiffness and filler alignment to the membrane surface depending on functional group nature.