Laser induced carbon nanotube microcapsules formation through depletion enhanced deposition
We report a method to fabricate carbon nanotube (CNT) microcapsule through laser induced bubble formation in a polyethylene glycol modified CNT (PEG CNT) solution in the presence of PEG. A low power laser is focused on a heat absorbing surface to create a bubble. While PEG CNTs in the solution are deposited on the bubble surface to form a microcapsule. The shape stability of microcapsule during swelling process is measured in different concentrations of PEG solutions. The stable CNTs microcapsules form with uniform spherical shape within 8 seconds in a 2% PEG solution, while PEG CNTs only randomly aggregate without the presence of PEG molecules. Thus, we propose that the deposition of PEG CNTs is enhanced by PEG molecules due to depletion interaction. Comparing with other methods, assembling PEG CNTs microcapsules at liquid air interface of polymer solution by optical heating greatly reduce the time and provide good quality of CNTs microcapsules. This study may enable applications of PEG CNTs microcapsules.We report a method to fabricate carbon nanotube (CNT) microcapsule through laser induced bubble formation in a polyethylene glycol modified CNT (PEG CNT) solution in the presence of PEG. A low power laser is focused on a heat absorbing surface to create a bubble. While PEG CNTs in the solution are deposited on the bubble surface to form a microcapsule. The shape stability of microcapsule during swelling process is measured in different concentrations of PEG solutions. The stable CNTs microcapsules form with uniform spherical shape within 8 seconds in a 2% PEG solution, while PEG CNTs only randomly aggregate without the presence of PEG molecules. Thus, we propose that the deposition of PEG CNTs is enhanced by PEG molecules due to depletion interaction. Comparing with other methods, assembling PEG CNTs microcapsules at liquid air interface of polymer solution by optical heating greatly reduce the time and provide good quality of CNTs microcapsules. This study may enable applications of PEG CNTs microcapsules.
AIP Advances