Hydrogels Based on Natural Polymers Loaded with Bentonite and/or Halloysite: Composition Impact on Spectroscopic, Thermal, and Swelling Properties.

Hydrogels are characterized by their property of absorbing and releasing a high content of water and water-based liquids; thus, they can be applied in agriculture as controlled-release water and fertilizer products. The focus of this research was efficient and low-cost natural polymer-based hydrogels obtained by crosslinking gellan gum (GGLA) and starch (ST) with acetic acid (CA) and loading them with either bentonite (BET) and/or halloysite (HAL). The hydrogels were obtained by mixing 100, 75, 50, 25, and 0 wt.

The Formation of Volume Transmission Gratings in Acrylamide-Based Photopolymers Using Curcumin as a Long-Wavelength Photosensitizer.

Curcumin, a natural dye found in the rhizome, commonly called turmeric, is used as a photosensitizer in acrylamide-based photopolymers for holographic data storage. We studied the absorbance of photopolymer films that show two absorption bands due to curcumin, acrylamide monomer (AA), and the crosslinking agent N,N'-methylenebisacrylamide (MBA). Analysis of the real-time diffraction efficiency of these films shows a maximum of 16% for the sample with the highest curcumin concentration.

Improved Conductivity in Gellan Gum and Montmorillonite Nanocomposites Electrolytes.

Nanocomposite polymer electrolytes (NPEs) were obtained using gellan gum (GG) and 1 to 40 wt.% of montmorillonite (NaSYN-1) clay. The NPEs were crosslinked with formaldehyde, plasticized with glycerol, and contained LiClO.

Surface Relief Grating on Chitosan-N,N-dimethyl-4-(2-pyridylazo)aniline Thin Film.

We deposited homogeneous, thin, yellow-colored films of chitosan (Chi)-N,N-dimethyl-4-(2-pyridylazo)aniline (PADA) dye from an acid Chi-PADA solution by spin-coating on glass substrates. We characterized Chi, PADA, and Chi-PADA films by ATR-FTIR spectroscopy, which revealed a slight shift of 3170 and 3268 cm bands, indicating H-bonding between the chitosan hydroxyl (OH) group and the amine (N) of the PADA pyridine ring. Based on these analyses, it was possible to determine the efficiency of the hydrogen bonds to form a Surface Relief Grating (SRG) on azo-polymer thin film.

Nanocomposite Polymer Electrolytes of Sodium Alginate and Montmorillonite Clay.

Nanocomposite polymer electrolytes (NPEs) were synthesized using sodium alginate (Alg) and either sodium (SCa-3-Na)- or lithium (SCa-3-Li)-modified montmorillonite clays. The samples were characterized by structural, optical, and electrical properties. SCa-3-Na and SCa-3-Li clays' X-ray structural analyses revealed peaks at 2θ = 7.

WO3 nanorods created by self-assembly of highly crystalline nanowires under hydrothermal conditions.

WO3 nanorods and wires were obtained via hydrothermal synthesis using sodium tungstate as a precursor and either oxalic acid, citric acid, or poly(methacrylic acid) as a stabilizing agent. Transmission electron microscopy images showed that the organic acids with different numbers of carboxylic groups per molecule influence the final sizes and stacking nanostructures of WO3 wires. Three-dimensional electron diffraction tomography of a single nanocrystal revealed a hexagonal WO3 structure with preferential growth along the c-axis, which was confirmed by high-resolution transmission electron microscopy.

Influence of plasticizer type on the properties of polymer electrolytes based on chitosan.

Polymer electrolytes were obtained by the casting technique from a solution containing chitosan, hydrochloric acid, and plasticizer such as glycerol, ethylene glycol, and sorbitol. The transparent membranes with good ionic conductivity properties were characterized by impedance and UV-vis spectroscopies, thermal analysis (DSC), and X-ray diffraction. The best ionic conductivity values of 9.