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Cellulose-based fibers are desirable materials for nonwoven wipes for their good absorbency, strength, cleaning, and biodegradable properties. However, quaternary ammonium compounds (QACs), being cationic in nature, show electrostatic interactions with anionic cellulosic fibers, reducing the available QACs to efficiently clean surfaces. This research presents sustainable alternative fibers that show better controlled exhaustion than commercial wipes and textile fibers. Textile and lignocellulosic fibers were prepared, soaked in QAC, and a UV–vis spectrophotometer was used to measure their exhaustion percentages. Factors such as immersion time and concentration of the disinfectant were also investigated, which affect the rate of exhaustion of the disinfectant from the fibers. A higher immersion time resulted in better exhaustion, whereas the total exhaustion decreased with an increase in the initial concentration of the disinfectant. The exhaustion of benzalkonium chloride (BAC) from the commercial wipes was also investigated at different immersion times and BAC concentrations. It was found that the wood and non-wood fibers showed more controlled exhaustion than the textile fibers and commercial wipes, and could be considered an alternative option for renewable and sustainable wipes and hygiene products. [ABSTRACT FROM AUTHOR]

The degree of crystallinity in cellulose significantly affects the physical, mechanical, and chemical properties of cellulosic materials, their processing, and their final application. Measuring the crystalline structures of cellulose is a challenging task due to inadequate consistency among the variety of analytical techniques available and the lack of absolute crystalline and amorphous standards. Our article reviews the primary methods for estimating the crystallinity of cellulose, namely, X-ray diffraction (XRD), nuclear magnetic resonance (NMR), Raman and Fourier-transform infrared (FTIR) spectroscopy, sum-frequency generation vibrational spectroscopy (SFG), as well as differential scanning calorimetry (DSC), and evolving biochemical methods using cellulose binding molecules (CBMs). The techniques are compared to better interrogate not only the requirements of each method, but also their differences, synergies, and limitations. The article highlights fundamental principles to guide the general community to initiate studies of the crystallinity of cellulosic materials. [ABSTRACT FROM AUTHOR]

Planar (2D) nanomaterials are garnering broad recognition in diverse scientific areas because of their intrinsic features. Herein, bulk graphitic carbon nitride (g-C 3 N 4 ) was prepared from melamine, which was exfoliated to produce g-C 3 N 4 nanosheets. The prepared g-C 3 N 4 nanosheets were characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), photo luminescence (PL) spectroscopy, and dynamic light scattering (DLS). The stable dispersion of a g-C 3 N 4 nanosheet was incorporated into a PVA/Gelatin matrix to explore its efficacy as a promising drug carrier. A remarkable 42% increase in tensile strength for 1% g-C 3 N 4 /PVA/Gelatin was attained compared with that of the PVA/Gelatin film. Thermal stability increased due to addition of g-C 3 N 4 nanosheet in the PVA/Gelatin film, where the maximum thermal degradation temperature increased by 9.5 °C when the 1% nanosheet was added to the PVA/Gelatin film. Moreover, the g-C 3 N 4 nanosheets and g-C 3 N 4 /PVA/Gelatin showed no cytotoxicity against HeLa and BHK-21 cells. To investigate the in vitro drug releasing efficacy, ciprofloxacin was incorporated into g-C 3 N 4 /PVA/Gelatin. Experimental results showed a 62% drug release within 120 min at physiological pH 7.4. The data was curve fitted by different kinetic models of drug release to understand the drug release mechanism. The experimental data was found to fit best with the Higuchi model and revealed the diffusion control mechanism of drug release. Additionally, antibacterial study confirmed the drug release potency from g-C 3 N 4 /PVA/Gelatin film on both Gram-positive and Gram-negative bacteria. The above-mentioned promising findings might lead to an opportunity of using g-C 3 N 4 as a potential drug carrier.

Hydrogels are three-dimensional porous polymeric networks prepared by physical or chemical cross-linking of hydrophilic molecules, which can be made into smart materials through judicious chemical modifications to recognize external stimuli; more specifically, this can be accomplished by the integration with stimuli-responsive polymers or sensing molecules that has drawn considerable attention in their possible roles as sensors and diagnostic tools. They can be tailored in different structures and integrated into systems, depending on their chemical and physical structure, sensitivity to the external stimuli and biocompatibility. A panoramic overview of the sensing advances in the field of hydrogels over the past several decades focusing on a variety protocols of hydrogel preparations is provided, with a major focus on natural polymers. The modifications of hydrogel composites by incorporating inorganic nanoparticles and organic polymeric compounds for sensor applications and their mechanisms are also discussed.