Another important feature is that many delicate shaped cellulose materials, e.g. nano-structured aerogels, do not survive immersion in liquids. In addition, due to the low-cost, high volatility and high reactivity of most common acylating reagents, acylations are an important class of reaction for modification of the properties of cellulosics. Even high boiling aliphatic acylating agents are of use, that can impart significant hydrophobicity to cellulosic materials at low degrees of substitution (DS) ).