Conductive Hydrogels Based on Industrial Lignin: Opportunities and Challenges

Self Cite

The extensive utilization of nonbiodegradable plastic agricultural mulch in the past decades has resulted in severe environmental pollution and soil fertility decline. Biodegradable mulch film (BMF) made from renewable resources has been considered an ideal alternative to traditional plastic mulch, offering a sustainable solution to address the challenges of plastic mulch recycling and the associated environmental contamination. More importantly, BMF is compostable, which has garnered significant attention in the realm of sustainable agriculture. This review summarizes recent advances in the application of renewable resources, including polysaccharide, protein, agricultural and forestry waste, and other biological feedstocks, for preparing BMF. Also, the physical characteristics and economic cost of BMF are discussed in detail. Lastly, current issues and future prospects are proposed for sustainable and cost-effective BMF.

Section: Agriculture Mulch From Degradable and Renewable Resourcesmentioning

confidence: 99%

Recent Advances of Biodegradable Agricultural Mulches from Renewable Resources

Li,

Liu,

wei

et al. 2023

Self Cite

“…Nevertheless, few attempts have been made in this system for renewable catechol-containing natural polymers, but there is a great need and promise for green preparation and sustainability. Lignin is a natural and the most abundant polyphenolic macromolecular that can trigger dynamic redox reactions with high-valent metal ions, thereby activating peroxide to generate free radicals that enable rapid gelation of gels at ambient temperatures. , Meanwhile, the addition of lignin can impart good mechanical properties, biocompatibility, and ultraviolet (UV) shielding properties to the gels, , which imparts lignin-based hydrogels with attractive sensing applications thereby. In contrast to water-insoluble lignin, sodium lignosulfonate shows excellent solubility in aqueous solutions without a modified reaction, which can be directly added into the hydrogel networks. , The use of aqueous Ls-based macromolecular initiator systems has been paid little attention.…”

Section: Introductionmentioning

confidence: 99%

“Deep Eutectic Solvent-in-Water” Hydrogels Enable High-Performance Flexible Strain Sensors for Electronic Skin with a Wide Operating Temperature Range

Wang

Xing

et al. 2023

Self Cite

Conductive hydrogels have become one of the hot topics in flexible strain sensors owing to excellent biocompatibility, attractive mechanical flexibilities, and conductive properties. However, the time-consuming preparation of hydrogels and their unsuitable properties limit their application in low-temperature environment and high temperatures. Here, a new class of “deep eutectic solvent-in-water” hydrogels (DIWHs) is reported for the first time through a one-step gelation process in situ without solvent displacement, fabricated by combining a hydrogel with deep eutectic solvent (DES). The DIWH is constructed using a dynamic oxidation and coordination system composed of sodium lignosulfonate (Ls) and Fe3+. The effect of DES and the optimal mass ratio of water and DES on the hydrogel properties was synthetically investigated. The addition of DES not only shortens the polymerization time to 8 s and enhances the mechanical properties of the hydrogel but also provides some unique properties. For example, the addition of DES gives the gels greater self-healing ability and antibacterial properties. When the mass ratio of water to DES was 1:3, excellent antifreezing and antidrying properties were imparted to the gel, and the elasticity of the hydrogel was maintained even at −80 °C or stored at 60 °C for 7 days. Furthermore, the hydrogel exhibited strong interfacial adhesion to natural and synthetic materials (up to 60 kPa on glass) due to the presence of Ls with a catechol structure. In conclusion, this work stimulates more interest in the sustainable and high-value utilization of DES and fully demonstrates the advantages of this new easy-to-prepare coacervation gel for sensing.

“…Green grease can also be created by mixing vegetable oil or animal fat with a green thickener . Several such green thickeners have been reported, such as methylated cellulose pulp, carboxymethyl guar gum, sorbitan or glyceryl monostearate, and modified lignin. − Modified lignin has become one of the most promising green thickeners due to its broad range of sources, excellent antioxidant properties, and biodegradable properties. , In the work done by Borrero-López et al, different diisocyanates (hexamethylene diisocyanate (HDI), isophorone diisocyanate (IDI), toluene diisocyanate (TDI), and 4,4′-methylene bis (phenyl isocyanate) (MDI))-modified alkali lignins have been tested as gelling agents in castor oil medium. In another work, researchers functionalized the side chains of different lignins with HDI in a toluene solution and used them as a thickener in castor oil to produce oleogels .…”

Section: Introductionmentioning

confidence: 99%

Facile Synthesis of Lignin-Castor Oil-Based Oleogels as Green Lubricating Greases with Excellent Lubricating and Antioxidation Properties

Wu,

Thoresen,

Matsakas

et al. 2023

In this study, a facile synthesis method was employed to create lignin-castor oil-based oleogels by modifying organic lignin with two silane coupling agents. The resulting oleogels demonstrated outstanding lubricating and antioxidation properties, establishing them as promising green lubricating greases. Compared with the pure castor oil, the oxidation induction time (OIT) value of the synthesized oleogels was significantly increased from 20 s (pure castor oil) to 1959 s (oleogel with 20 wt % lignin), indicating an effective improvement of the oxidation resistance. The steel contacts lubricated by the synthesized oleogel also had lower wear than those lubricated by pure castor oil, signifying the better lubricating properties of oleogels. The oleogel with 20 wt % lignin showed the lowest wear, which was around 64% lower than that of pure castor oil. The exceptional performance and environmentally sustainable composition of these oleogels, with the biomass content exceeding 80%, allow them to be used as green lubricating greases for industrial applications. Overall, this study provides valuable insights into the development of high-performance, eco-friendly lubricants.