Solvent-free functionalization of carbon nanotube buckypaper with amines

Enhancing the fracture toughness of hierarchical composites through amino‒functionalised carbon nanotube webs

“…A similar mismatch is seen between the calculated EAM value and the CNT surface cover for the other alkyl amines (DAD, TET), whereas the aromatic compound DAN is closer with 23% EAM and 18% CNT coverage. Although these are at best approximations, this suggests that the DAN predominantly lies flat on the CNT surface as might be expected due to aromatic π-π interactions whose importance has already been demonstrated [33]. Raman spectroscopy and SEM was performed on the untreated pristine CNTw and also on the EDA treated one ( Figure S3).…”

“…Some of those authors functionalised CNT buckypapers with amines in gas-phase [33] and observed also a stepwise TGA curve, with a weight loss between approximately 400 °C and 600 °C, which was attributed to the CNT surface layer bearing covalently attached amines. Herein it should be highlighted that molecular dynamics simulations have shown that the physical adsorption of amines over a CNT surface takes place preferentially at defect rich areas, interacting with five-membered rings [16] or carboxylic groups [33]. Thus the amount of diamine incorporated in each case is calculated from the weight loss between 200 °C and 410 °C while weight lost between 410 °C and 550 °C is attributed to degradation of the CNT surfaces to which the diamine molecules had been physi-or chemisorbed ( Table 1).…”

“…From the amine TGA curves and first derivatives ( Figure S2), the first of the two weight losses (between 200 and 410 °C) is ascribed to physisorbed molecules. The second weight loss would usually be attributed to covalently bonded molecules [16,[33][34][35] however this does not seem to be the case here since it occurs at a temperature too high (410 °C to 550 °C) to be considered chemisorbed diamines. Chattopadhyay et al [36] assigned a weight loss between 150 °C and 300 °C to a CNT physisorbed aliphatic amine and Basiuk et al [16,[33][34][35] assigned weight losses below 200 °C to physisorbed amines, while losses between 200 °C and 360 °C were attributed to covalently bonded species.…”

“…The second weight loss would usually be attributed to covalently bonded molecules [16,[33][34][35] however this does not seem to be the case here since it occurs at a temperature too high (410 °C to 550 °C) to be considered chemisorbed diamines. Chattopadhyay et al [36] assigned a weight loss between 150 °C and 300 °C to a CNT physisorbed aliphatic amine and Basiuk et al [16,[33][34][35] assigned weight losses below 200 °C to physisorbed amines, while losses between 200 °C and 360 °C were attributed to covalently bonded species. Some of those authors functionalised CNT buckypapers with amines in gas-phase [33] and observed also a stepwise TGA curve, with a weight loss between approximately 400 °C and 600 °C, which was attributed to the CNT surface layer bearing covalently attached amines.…”

“…Chattopadhyay et al [36] assigned a weight loss between 150 °C and 300 °C to a CNT physisorbed aliphatic amine and Basiuk et al [16,[33][34][35] assigned weight losses below 200 °C to physisorbed amines, while losses between 200 °C and 360 °C were attributed to covalently bonded species. Some of those authors functionalised CNT buckypapers with amines in gas-phase [33] and observed also a stepwise TGA curve, with a weight loss between approximately 400 °C and 600 °C, which was attributed to the CNT surface layer bearing covalently attached amines. Herein it should be highlighted that molecular dynamics simulations have shown that the physical adsorption of amines over a CNT surface takes place preferentially at defect rich areas, interacting with five-membered rings [16] or carboxylic groups [33].…”