Based on conventional Novolak phenolic resins

organic aerogels were prepared by sol-gel method.By optimizing the microscopic pore structure of organic aerogels through modifying concentration of the cross-linking agent of HMTA

the capillary force of solvent for wet aerogels during drying was obviously decreased.Thus

the aerogels could be easily obtained by ambient drying with slight shrinkage and well skeleton strength.The effects of HMTA on the microstructure of pores

apparent density

thermal stability

mechanical properties and other performances of organic aerogels were detailedly studied.The pore textural and morphological studies showed that the average pore diameter of organic aerogels decreased and the specific area increased with increasing HMTA concentration.When the concentration of HMTA was 0.2 mol/L

the average pore diameter of aerogel was up to 100 nm.The nano-scaled pore diameter and fine distribution of pore diameter can help to promote the stability of organic aerogels skeleton.Compared to the aerogel with micro-scaled pore diameter

the compression strength and modulus of aerogel with nano-scaled pore diameter were apparently improved.Because of the increase of HMTA concentration

lots of unstable NCH2 groups were incorporated into the phenolic aerogel

which may lead to the decrease of thermal stability for phenolic organic aerogel.