Formation of Chitosan/Sodium Phytate/Nano-Fe3O4 Magnetic Coatings on Wood Surfaces via Layer-by-Layer Self-Assembly

Abstract

Magnetic wood would have potential uses in electromagnetic shielding and electromagnetic wave absorption. In this paper, magnetic coatings on a wood surface were synthesized using a layer-by-layer self-assembly method. As the cationic polyelectrolyte carrier, natural macromolecular chitosan was pre-immobilized on a wood surface first, followed by the alternate adsorption of anionic polyelectrolyte sodium phytate and positively-charged Fe3O4 nanoparticles. The concentration of pH-controlled chitosan solution, sodium phytate solution, and Fe3O4 nanoparticle suspension, soaking time, and the number of alternating sedimentary layers varied. The morphology and crystal structure of the Fe3O4 modified wood samples were studied using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The magnetic hysteresis loops showed that the modified wood had magnetic properties which were improved as the number of assembled layers increased.

Investigation of Synthesis Mechanism, Optimal Hot-Pressing Conditions, and Curing Behavior of Sucrose and Ammonium Dihydrogen Phosphate Adhesive

“…Due to decreasing fossil fuel resources and rapidly increasing environmental awareness, the utilization of renewable resources has become a focus of materials science research [1][2][3][4]. As a consequence, many novel bio-based materials have been developed and are expected to be utilized in many fields [5][6][7][8][9][10]. Wood-based materials (such as particleboard [11], plywood [12], oriented strand board [13], and fiberboard [14]) are common in everyday living environments, and are typically fabricated using formaldehyde-based resins to obtain excellent bonding performance [15][16][17].…”

Trends in Chemical Wood Surface Improvements and Modifications: A Review of the Last Five Years

“…The developed coating was highly durable, keeping a contact angle higher than 150 • after UV exposition and degradation by HCl, NaOH, n-hexane, acetone, ethanol, DMF and boiling water. A magnetic wood coating based on chitosan, sodium phytate and nano-Fe 3 O 4 was prepared by Tang and Fu through layer-by-layer deposition [144]. They found that paramagnetic wood with narrow and long magnetic hysteresis loops could be created with this method, the magnetic properties of the treated wood being directly related to the number of layers in the coating.…”

“…These treatments, mostly belonging to the organic coatings' trends, included bio-based monomers for film-forming coatings [41][42][43][44]47], modified vegetal oils [39,40,45,46,51,55,56], biological polymers (chitosans, lignin, etc.) [57,58,92], and more [52,53,76,90,[143][144][145]. Many advantages come along with these materials, from the cradle to the grave.…”

Surface Properties of Spray-Assisted Layer-By-Layer ElectroStatic Self-Assembly Treated Wooden Take-Off Board

“…These LbL-assembled films on fibers result in new properties that are difficult to achieve with pulp fiber substrates [18][19][20][21]. Impregnated LbL self-assembly films have the advantage of simple equipment requirements and operational needs; however, disadvantages include the requirements of repeated impregnation, rinsing, and drying [22,23]. Moreover, the film formation is time-consuming; thus, impregnated LbL self-assembly film is a complicated procedure that has become one of the most significant bottlenecks in the development of this technology [24].…”