Abstract
M.Sc. (Nanoscience)
Flexible polymer nanocomposites thin films holds promising applications in electronics and are good candidates for pressure sensing and other technological applications due to their flexibility and other novel properties they exhibits. Carbonaceous nanomaterial polymer nanocomposites were utilized to fabricate pressure sensors via a simple and cost- effective process of non-covalent functionalization.
We successfully managed to demonstrate the use of cheap, stable, thermoplastic polymers for producing thin films for pressure sensing applications and applicable also for future electronic devices applications. The use of CNPs gave better resistive and capacitive sensing application with response times ranging from 3 to 11 seconds and operate effective for a wide dynamic range (56 to 190 kPa) for both resistive and capacitive sensing compared to O-MWCNTs. The sensitivities of carbonaceous nanomaterials are dependent on the nature of the polymer, loadings of polymer ratios (1:1, 1:2, 1:3, 2:1, 2:2, 2:3, 3:1, 3:2 and 3:3) and percolation threshold.
CNPs/PAN pressure sensor was measured for electrical resistance and capacitance pressure sensing. The CNPs/PAN was the highest sensitivity resistive pressure sensor than any other in relation to O-MWCNTs and rGO – based pressure sensors having 5.12 kPa-1. CNPs/PAN took three second to reach 90% pressure stimuli response time and also it took in three seconds for 90 % recovery time to retain its initial state at Ro under applied pressure with linear range from 56 to 190 kPa.
Capacitive sensitivity was 1.33 kPa-1 for CNPs and CA thin film pressure sensor exhibiting linearity with a wide dynamic range and reversible behaviour. When Fe3O4 was incorporated to CNPs and CA, low sensitivities for resistive and capacitive pressure sensing were obtained for CNPs/Fe3O4/CA. Resistive sensitivity was 2.08 x 10-6 kPa-1 and 0.04 kPa-1 for capacitive sensitivities. This implies that, Fe3O4 had a huge impact on the structure, arrangement, uniformity, distribution and conducting channels within the polymer nanocomposites. As for O-MWCNTs and rGO –based pressure sensors, similar reduction in sensitivities due to Fe3O4...