Design and development of trivalent Fe ion-induced novel urushi organogels

Effects of Fe Ions, Ultraviolet Irradiation, and Heating on Microscopic Structures of Black Lacquer Films

“…8 The development of several functional materials using these cross-linked structures has also been reported. 3,7,8,17 When black lacquer is used as a paint, it easily discolors under sunlight and heat. Understanding the effects of Fe addition, heating, and UV irradiation on the microscopic structural changes in urushi films is important from artistic and archeological perspectives, as well as for materials development.…”

“…Urushi (lacquer) is a natural paint with excellent water and chemical resistance, and has been used as a paint for coating various daily necessities and decorations since ancient times. , Recently, urushi has also been attracting attention as a renewable natural polymer for developing organogels, composite membranes for battery applications, , functional nanoparticles, catalysts, adhesives, , and biomaterials with antioxidant activity . In general, lacquer consists of the lipid urushiol (∼65%, Figure ), water (∼30%), polysaccharides (∼7%), glycoproteins (∼5%), and laccase enzymes (∼0.1%). − Adding a metal, such as Fe or Hg, or a pigment into raw lacquer, which is naturally brown, produces colors such as black, vermillion, and white. , …”

Nano-emulsification of oriental lacquer sap by ultrasonic wave propagation: Improvement of thin-film characteristics as a natural resin

“…The enzyme-catalysed polymerisation of oriental lacquer sap collected from lacquer trees in Asia allows it to be used as an energy-saving and environmentally friendly coating material with antibacterial, antiseptic, waterproof, and chemically resistant actions [1] , [2] , [3] , [4] , [5] , [6] , [7] . The lacquer thin films ensure excellent physicochemical properties such as high thermal stability, superior durability, anti-corrosiveness, good adhesion, and high gloss [8] , [9] , [10] . However, the drying process, which requires severe and strict conditions (approximately 70–90% relative humidity (RH) at 20–30 °C), has been issued a critical factor that hinders practical application in industrial fields, even though it is a biodegradable, renewable resource.…”

Urushiol-Induced Hydrogels with Long-Term Durability and Long Service Lifespan in Mechanosensation

“…Urushiol (UH, Figure a), a natural and cheap catechol derivative from lacquer trees, is composed of a rigid catechol group and an unsaturated flexible side alkane chain with 0–3 double bonds and 15–17 carbons. , The UH has been developed as a superb adhesive to diverse substrates in air and water on account of the existence of catechol groups (the effective moieties of mussels-inspired adhesive) and long hydrophobic alkyl chains. , Interestingly, the hydrophobic alkyl chains tend to protect catechol groups from oxidation, optimizing the self-adhesiveness of HWSs. Furthermore, the relatively long unsaturated side alkyl chain in UH possesses fast mobility in hydrogels or organogels, representing a certain flexibility . The UH can also serve as a cross-linking agent to ameliorate the mechanical strength and recyclability of aerogel .…”

“…Furthermore, the relatively long unsaturated side alkyl chain in UH possesses fast mobility in hydrogels or organogels, representing a certain flexibility. 32 The UH can also serve as a cross-linking agent to ameliorate the mechanical strength and recyclability of aerogel. 33 Therefore, it is hopeful to construct a wellelaborated polymer network structure and empower the hydrogel sensors with long-term durability via introducing the urushiol into hydrogels.…”