Structure and properties of regenerated cellulose/tourmaline nanocrystal composite films

Abstract

Nanocomposite films were successfully prepared from cellulose and tourmaline nanocrystals with mean diameters of 70 nm in a 1.5 M NaOH/0.65 M thiourea aqueous solution by coagulation with 5 wt % CaCl 2 and then a 3 wt % HCl aqueous solution for 2 min. The structure and properties of the composite films were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and tensile testing. The results indicated that the tourmaline nanocrystals were dispersed in a cellulose matrix, maintaining the original structure of the nanocrystals in the composite films. The loss peaks (tan ␦) in the DMA spectra and the decomposition temperatures in the DSC curves of the composite films were significantly shifted toward low temperatures, suggesting that the nanocrystals broke the partial intermolecular hydrogen bonds of cellulose, and this led to a reduction in the thermal stability. However, the nanocomposite films exhibited a homogeneous structure and dispersion of the nanocrystals. When the tourmaline content was in the range of 4 -8 wt %, the composite films possessed good tensile strength (92-107 MPa) and exhibited obvious antibacterial action against Staphylococcus aureus. This work provides a potential way of preparing functional composite films or fibers from cellulose and nanoinorganic particles with NaOH/thiourea aqueous solutions.

Characterization and temperature-dependent conductivity of polyaniline nanocomposites encapsulating gold nanoparticles on the surface of carboxymethyl cellulose

“…A Keithly 224 constant current source and a Keithly 617 digital electrometer were used. [29][30][31]. The band regions shifted slightly lower than the neat CMC, confirming the presence of AuNPs in the CMC polymer.…”

New fabricate of styrene–butadiene rubber/montmorillonite nanocomposites by anionic polymerization

“…The value of T d1 of S-25M4 is lower than that of S-25M2.5 and S-25M3. This can be attributed to the slight phase separation with further introduction of OMMT [27]. The DTG results can more clearly illustrate the difference in thermal decomposition behavior of all samples.…”

Efficient adsorption behavior of phosphate on La-modified tourmaline

“…The important feature of tourmaline is the generation of spontaneous and permanent poles which can produce an electric dipole. It is capable of radiating far infrared energy, permanently releasing negative ions, producing an electric field and releasing rare microelements [18]. Meanwhile, the solution pH in the presence of tourmaline can be automatically controlled to near neutral pH [19].…”