Biogenic silica with amazing diversity of nanostructure shells, fibers andgranules in diatoms and sponges is mediated by proteins and polysaccharides and forms at ambientpressure and temperatures. Chemical synthetic m...Biogenic silica with amazing diversity of nanostructure shells, fibers andgranules in diatoms and sponges is mediated by proteins and polysaccharides and forms at ambientpressure and temperatures. Chemical synthetic methods, in contrast, have to rely on extreme pHand/or surfactants to induce the condensation of silica precursors into specific patterns. One kindof benign synthesis method through plant cell wall template-directed ordered biosilica materialsunder ambient conditions is intriguing in this context. Organized silica materials in intercellularspaces of epidermal cells of tall fescue leaves were synthesized through molecular recognitionbetween Si-OH and polysaccharide-OH or glycoprotein-OH of main components of plant cell walls andcellular processing as well when Si(OEt)_4 was supplied rather than monosilicic acid. Thebiosynthesis of structural silica in tall fescue plant was correlated with the Si species applied,reflecting the slower condensation from tetraethoxysilane (TEOS) and thus providing greateropportunities for structural control by the underlying matrix of cell walls. The composition wasestimated by energy dispersive X-ray (EDX) spectra on a scanning electron microscope. All organizedstructures showed carbon, oxygen and silicon peaks, indicating that their formations differ fromnatural siliceous process.展开更多
基金theNationalNaturalScienceFoundationofChina (No 39870 480 )andNationalKeyBasicResearchFoundation(No.G19990 1170 0 )
文摘Biogenic silica with amazing diversity of nanostructure shells, fibers andgranules in diatoms and sponges is mediated by proteins and polysaccharides and forms at ambientpressure and temperatures. Chemical synthetic methods, in contrast, have to rely on extreme pHand/or surfactants to induce the condensation of silica precursors into specific patterns. One kindof benign synthesis method through plant cell wall template-directed ordered biosilica materialsunder ambient conditions is intriguing in this context. Organized silica materials in intercellularspaces of epidermal cells of tall fescue leaves were synthesized through molecular recognitionbetween Si-OH and polysaccharide-OH or glycoprotein-OH of main components of plant cell walls andcellular processing as well when Si(OEt)_4 was supplied rather than monosilicic acid. Thebiosynthesis of structural silica in tall fescue plant was correlated with the Si species applied,reflecting the slower condensation from tetraethoxysilane (TEOS) and thus providing greateropportunities for structural control by the underlying matrix of cell walls. The composition wasestimated by energy dispersive X-ray (EDX) spectra on a scanning electron microscope. All organizedstructures showed carbon, oxygen and silicon peaks, indicating that their formations differ fromnatural siliceous process.
