I have alkylated graphene oxide via reaction with alkylamine. FTIR spectrum shows that what the peak around 3400 is more intense after functionalization? what is the reason behind this?
Generally, alkylation of graphine oxide is carried out via two steps: nucleophilic addition of n-butyllithium (n-BuLi) to the GO sheets and a subsequent coupling and etherification reaction of the intermediates (Bu-GO)n−Lin+ and alkyl halide (such as alkyl bromide) leading to functionalized GO:
Reaction of GO with alkylamine is expected to form the corresponding ammonium salt of GO (ionization of the carboxylic groups present in GO) and it is hard to believe that alkylation of GO can take place via this method.
Please see GO structure illustrated in the following link:
In order to confirm what I proposed, take a quantity of your product, acidify with HCl, wash with water, filter, dry and take FTIR. The FTIR for the material after acidification should be identical to that of the starting material (graphene oxide).