More than 10 million tons of textile waste are disposed through landfill every year in North America. The disposal of textile waste via landfill or incineration causes environmental problems and represents a waste of useful resources. In this work, we explored the possibility to directly extract cellulose nanocrystals (CNCs) from untreated textile waste through two methods, namely sulfuric acid hydrolysis and three-step oxidization. CNCs with cellulose I_β crystalline structure and rod-like shape were successfully obtained. The aspect ratios of CNCs prepared from acid hydrolysis and oxidization were 10.00 ± 3.39 and 17.10 ± 12.85, respectively. Their application as reinforcing agent of soybean protein isolate (SPI) film was evaluated. With the addition of 20% CNCs, the composite film maintained the high transparency, while their water vapor barrier property, tensile strength, and Young’s modulus were significantly improved. This research demonstrates a promising approach to recycle textile waste, and more value-added applications based on the derived CNCs could be expected.

Increasing utilization of textiles has raised concern regarding the environmental impact brought by the textile manufacturing process and disposal of waste textiles. In our previous work, the dissolution of cotton waste through different solvent systems was demonstrated. Herein, this study aimed to further investigate the recycling of waste cotton–elastane fabrics using H₂SO₄, NaOH/urea, and LiCl/DMAc solvent systems. The structure of regenerated films was characterized with Fourier transform infrared spectroscopy and scanning electron microscopy, and the properties of the regenerated films, including transparency, mechanical properties, water vapor permeability, and thermal stability, were investigated. The results revealed that all solvent systems could convert the waste cotton–elastane fabrics into regenerated films with the existence of different forms of elastane components. The elastane fibers were partially hydrolyzed in H₂SO₄ solvent and reduced the transparency of regenerated films, but they were well retained in NaOH/urea solvent and interrupted the structure of regenerated cellulose films. It is worth noting that the elastane fibers were completely dissolved in LiCl/DMAc solvent and formed a composite structure with cellulose, leading to obviously improved tensile strength (from 51.00 to 121.63 MPa) and water barrier property (from 3.50 × 10⁻⁷ to 1.03 × 10⁻⁷ g m⁻¹ h⁻¹ Pa⁻¹). Therefore, this work demonstrates the possibility to directly recycle waste cotton–elastane fabrics through dissolution and regeneration, and the resultant films have potential applications as packaging materials.

Colorimetric oxygen indicators can be applied for non-destructive testing in packaging; especially in modified atmosphere packaging (MAP). In this paper; titanium dioxide (TiO₂) nanotube; which is used as a semiconductor photocatalyst in oxygen indicators; was synthesized via a microwave-assisted hydrothermal method. X-Ray Diffraction (XRD) was used to analyze its crystal form and Scanning Electron Microscope (SEM).to characterize its morphology. Its properties were studied using Brunauer-Emmett-Teller (BET), Diffuse Reflection Spectrum (DRS), and Bluebottle experiments. The results showed that the synthesized TiO₂ nanotube was a mixture of rutile and anatase; with a specific surface area of 190.35 m²/g; and a wide band gap of 3.34 eV. Given the satisfactory performance; the TiO₂-based oxygen indicator was prepared and combined with glycerol; methylene blue; and hydroxyethyl cellulose (HEC). The oxygen indicator demonstrated excellent photocatalytic performance and effectively avoided excitation by visible light. We studied the rheological properties; thixotropic properties; and wettability of the indicator. The results demonstrated the printability of the indicator solution; which was then printed in the polyethylene terephthalate (PET) film by screen printing and applied to MAP. The application results showed that the prepared oxygen indicator was able to provide visual support to judge whether the packaging was intact and the food was safe.

Cellulose nanocrystals as reinforcing agents have received considerable interest, and their dimension mainly depends on the original sources of cellulose. We intend to manually modulate the morphology of cellulose nanocrystals by treating them with cellulose solvents so that we can explore their reinforcing capacity. In this work, waste cotton fabric was processed in two aqueous solvents (a sulfuric acid aqueous solution and a NaOH/urea aqueous solution), and the regenerated cellulose was used to produce cellulose nanocrystals using acid hydrolysis. The results revealed that the nanocrystals (RCNC-H) obtained after the treatment in sulfuric acid had a hybrid crystalline structure and a needle-like shape with an aspect ratio of about 15.2, while cotton fabric was completely dissolved in the NaOH/urea aqueous solution, and the regenerated nanocrystals (RCNC-N) displayed a typical crystalline form of cellulose II with a higher crystallinity and a shorter rod-like shape with an aspect ratio of about 6.3. The reinforcing effects of RCNC-H and RCNC-N were evaluated using polyvinyl alcohol (PVA) films as a model, where the addition of RCNC-H resulted in a relatively better tensile strength and oxygen barrier property, and the PVA/RCNC-N films had a slightly lower water vapor permeability. Therefore, this work suggests a new possibility for altering the naturally formed nanostructure of cellulose for different applications.

The amount of biomass wastes is rapidly increasing, which leads to numerous disposal problems and governance issues. Thus, the recycling and reuse of biomass wastes into value-added applications have attracted more and more attention. Waste paper is a major contributor to municipal and industrial waste, and its recycle and reuse are a current challenge. We presented the conversion