This work proposes a new approach to fabricate highly transparent and flexible composite films that exhibit enhanced UV-shielding properties. Lignin has innate UV-shielding properties. However, when purified lignin, which is conventionally extracted through chemical treatment, is mixed with polymeric materials, its presence negatively influences the transparency of the resulting composite. High transparency and UV-shielding are desirable properties for many applications. In this study, composites were made by mixing lignocellulose particles and polyvinyl alcohol (PVA), where lignocellulose particles were obtained from ball-milled waste hemp hurd without chemical treatments. The UV-shielding properties of the resulting composite film, as a function of hemp/PVA weight ratios, were investigated. The intermolecular interactions between the hemp particles and the PVA were characterized using infrared spectroscopy with the presence of –C=O group at 1655 cm⁻¹, providing evidence that the chemical structure of lignin was preserved. The fabricated hemp/PVA films exhibit stronger UV-shielding, in the UVA-I range (340–400 nm) than TiO₂/PVA films. The composite films also showed comparable water vapor permeability (WVP) with commercial packaging plastic film made of HDPE (high-density polyethylene). The optimization experiments were reported, with aim at understanding the balance between the UV-shielding and mechanical properties of the hemp/PVA films. The findings of this work can be applicable to the packaging, food and cosmetic industries where UV shielding is of utmost importance, hence adding value to hemp hurd waste.

Microplastics (MPs), particularly fibrous MPs, have emerged as a significant environmental concern due to their pervasive presence in aquatic and terrestrial ecosystems. The textile industry is a significant contributor to MP pollution, particularly through the production of synthetic fibers and natural/synthetic blends, which release substantial amounts of fibrous MPs. Among the various types of MPs, fibrous MPs account for approximately 49–70% of the total MP load found in wastewater globally, primarily originating from textile manufacturing processes and the domestic laundering of synthetic fabrics. MP shedding poses a significant challenge for environmental management, requiring a comprehensive examination of the mechanisms and strategies for the mitigation involved. To address the existing knowledge gaps regarding MP shedding during the textile production processes, this brief review examines the current state of MP shedding during textile production, covering both dry and wet processes, and identifies the sources and pathways of MPs from industrial wastewater treatment plants to the environment. It further provides a critical evaluation of the existing recycling and upcycling technologies applicable to MPs, highlighting their current limitations and exploring their potential for future applications. Additionally, it explores the potential for integrating sustainable practices and developing regulatory frameworks to facilitate the transition towards a circular economy within the textile industry. Given the expanding application of textiles across various sectors, including medical, agricultural, and environmental fields, the scope of microplastic pollution extends beyond conventional uses, necessitating urgent attention to the impact of fibrous MP release from both synthetic and bio-based textiles. This brief review consolidates the current knowledge and outlines the critical research gaps to support stakeholders, policymakers, and researchers in formulating effective, science-based strategies for reducing textile-derived microplastic pollution and advancing environmental sustainability.

Lignin is a natural light-coloured ultraviolet (UV) absorber; however, conventional extraction processes usually darken its colour and could be detrimental to its UV-shielding ability. In this study, a sustainable way of fabricating lignin–cellulose nanocrystals (L-CNCs) from hemp hurd is proposed. A homogeneous morphology of the hemp particles was achieved by ball milling, and L-CNCs with high aspect ratio were obtained through mild acid hydrolysis on the ball-milled particles. The L-CNCs were used as filler in polyvinyl alcohol (PVA) film, which produced a light-coloured nanocomposite film with high UV-shielding ability and enhanced tensile properties: the absorption of UV at wavelength of 400 nm and transparency in the visible-light region at wavelength of 550 nm was 116 times and 70% higher than that of pure PVA, respectively. In addition to these advantages, the nanocomposite film showed a water vapour transmission property comparable with commercial food package film, indicating potential applications.

Traditional soluble phosphorous (P) fertilisers can be easily leached to pollute water systems, resulting in water eutrophication, a major environmental problem from the oversupply of unused nutrients. One innovative solution is to control the release of P upon demands of the plants. This study established a new concept of controlled-release P fertiliser via incorporation of ferric phosphate (FePO₄) as a P source in polyvinyl alcohol (PVA) films, which can immobilise the FePO₄ particles and stimuli-responsively accelerate their release rate in the presence of citric acid. More importantly, FePO₄ used in this work originated from steelmaking slag as a potential waste reuse. Due to the low solubility of FePO₄, diethylamine was introduced to modify FePO₄ particles to facilitate the release of P before incorporating with PVA. The effects of diethylamine modification and the properties of FePO₄/PVA films were systematically investigated through microscopic and spectroscopic methods. The release of P from particles and films was examined in both deionised water and citric acid solution for 30 days. The results showed a tenfold increase of the release rate of modified FePO₄/PVA in citric acid solution compared with that in deionised water, and also a doubled release rate of the modified FePO₄/PVA compared to that of FePO₄/PVA in citric acid. The improved performance suggests that PVA can maintain the phosphorous content with exposure to water and expedite release in citric acid upon the demand of plants. This composite film offers a new opportunity for the application of insoluble phosphate as a phosphorous fertiliser.

Lignin is a natural source of UV-shielding materials, though its recalcitrant and heterogeneous structure makes the extraction and purification processes complex. However, lignin’s functionality can be directly utilised when it stays as native with cellulose and hemicellulose in plant biomass, rather than being separated. The fabrication process of this native lignin is sustainable, as it consumes less energy and chemicals compared to purified lignin; thus, it is an economic and more straightforward approach. In this study, the properties of native and purified lignin–cellulose nanocrystals (L–CNCs) sourced from hemp hurd waste were compared to explore the differences in their morphology, UV-shielding properties and chemical structure affected by their distinct fabrication process. These two kinds of L–CNCs were further added into polyvinyl alcohol (PVA) to evaluate their reinforcement characteristics. The resulting native L–CNCs/PVA film showed stronger UV-shielding ability than purified L–CNCs. Moreover, the native L–CNCs showed better compatibility with PVA, while the purified L–CNCs/PVA interfaces showed phase separation. The phase separation in purified L–CNCs/PVA films reduced the films’ tensile strength and Young’s modulus and increased the water vapour transmission. The laboratory-scale cost of native L–CNCs production (~AUD 80/kg) was only 10% of purified L–CNCs (~AUD 850/kg), resulting in a comparatively lower cost for preparing native L–CNCs/PVA composite films. Overall, this study shows that the proposed method of production and use of native L–CNCs can be an economic approach to deliver UV-shielding properties for potential applications, such as food packaging.