I tried to lyophilize tannins from NaOH solution (at - 45 C), however the final product is not in powder form. It is black color slurry (sticky product). Is it normal for recovered tannin products by applying lyophilization method?
Tannin is precipitated as lead tannates(10%) from aqueous solution as ppt. which can be removed bynormal filtration.On drying one can get a power of lead tannate.
Is it means if I lyophilize the tannins from NaOH solution (without any further treatment), the final product must be sticky and impossible to exist as powder product ?