FTIR microscopy and ultrastructural investigation of silylated solid wood

The reaction of two silylating agents (TMSIM, TMS-acetamide) on softwood (white fir) and hardwood (beech) is examined. As proved by means of FTIR microscopy, silylation takes place at the outer surface as well as the inner surface. The FTIR spectroscopical features of both softwood and hardwood remain unchanged. Scanning electron microscopy provides additional evidence that the inner surface is also successfully silylated. Furthermore, the anatomical characteristics of the silylated wood species are not changed. No inorganic elements except silicon could be detected in the EDX-analysis. By means of transmission electron microscopy the reaction site was determined to be on the lumen-faced side of the cell wall. Half of the S2 wall appears to be silylated.