Part One: Conductive behaviour of graphene/carbon nanotube and graphene oxide/ carbon nanotube hybrid materials
Experimental
Introduction
Although many CNTs and graphene based electrodes have been developed with outstanding properties, drawbacks are still noticeable using some methods. For instance, EPD method commonly produces unsatisfied CNTs film strength and on the other hand, CVD technique is costly. Moreover, graphene based electrodes needs lots of labour works which is time consuming and costly. Hence, there are still some hindrances in controlling CNT and graphene film preparation to get the large scale quality and the massive quantity[1][2]. Very recently, a simple and practical solution-casting method has been used to prepare the …show more content…
The preparation of graphene is as follows: The expandable graphite was mixed with powder melamine in volume ratios of 1:1 and 1:3 to produce several mixtures as shown in table 2-1. The mixtures were dispensed into the de-ionised water to make solutions with a concentration of 1g/100ml. The solutions were then heated up to and kept at 80oC for 1 hour with constant stirring. This is to allow the melamine to fully penetrate and expand the graphite spaces. Later, the solutions were filtrated and dried for five hours at 80oC. The dried mixtures then underwent ball-milling to initially exfoliate the graphite layers, and then dispersed in de-ionised water and underwent further exfoliation with sonication for 1 hour using Ultrasonic machine ( Fisher scientific Sonic Dismembrator Model 500, 300 W). Finally, to remove the melamine, hot water was used to repeatedly wash the mixtures. The prepared graphene and its water dispersion are presented in Figure 2 …show more content…
SWCNTs, or MWCNTS, or MWCNTs-OH was also dissolved in distilled water by the assistance of ultra-sonication for the same time using Ultrasonic machine ( Fisher scientific Sonic Dismembrator Model 500, 300 W). Then GO/distilled water dispersion and SWCNTs, or MWCNTs, or MWCNTs-OH/distilled water dispersion were mixed to make different concentration by controlling the volume of GO. All the mixtures were then treated by ultrasonic separately for another 30mins. After this, each mixture was dropped on a cover slip placed in a glass container as in Figure 2 3. The hybrid thin films coated on the coverslips were obtained after drying for 3 days (in a vacuum oven for the 3rd day) at 40oC. The thickness of the films was controlled by the volume of the mixture dropped on the cover slip. The coated hybrid films were obtained after drying for one day at 40oC oven and then in a vacuum oven of 60 oC for 3 days as shown in Figure 2
Experimental
Introduction
Although many CNTs and graphene based electrodes have been developed with outstanding properties, drawbacks are still noticeable using some methods. For instance, EPD method commonly produces unsatisfied CNTs film strength and on the other hand, CVD technique is costly. Moreover, graphene based electrodes needs lots of labour works which is time consuming and costly. Hence, there are still some hindrances in controlling CNT and graphene film preparation to get the large scale quality and the massive quantity[1][2]. Very recently, a simple and practical solution-casting method has been used to prepare the …show more content…
The preparation of graphene is as follows: The expandable graphite was mixed with powder melamine in volume ratios of 1:1 and 1:3 to produce several mixtures as shown in table 2-1. The mixtures were dispensed into the de-ionised water to make solutions with a concentration of 1g/100ml. The solutions were then heated up to and kept at 80oC for 1 hour with constant stirring. This is to allow the melamine to fully penetrate and expand the graphite spaces. Later, the solutions were filtrated and dried for five hours at 80oC. The dried mixtures then underwent ball-milling to initially exfoliate the graphite layers, and then dispersed in de-ionised water and underwent further exfoliation with sonication for 1 hour using Ultrasonic machine ( Fisher scientific Sonic Dismembrator Model 500, 300 W). Finally, to remove the melamine, hot water was used to repeatedly wash the mixtures. The prepared graphene and its water dispersion are presented in Figure 2 …show more content…
SWCNTs, or MWCNTS, or MWCNTs-OH was also dissolved in distilled water by the assistance of ultra-sonication for the same time using Ultrasonic machine ( Fisher scientific Sonic Dismembrator Model 500, 300 W). Then GO/distilled water dispersion and SWCNTs, or MWCNTs, or MWCNTs-OH/distilled water dispersion were mixed to make different concentration by controlling the volume of GO. All the mixtures were then treated by ultrasonic separately for another 30mins. After this, each mixture was dropped on a cover slip placed in a glass container as in Figure 2 3. The hybrid thin films coated on the coverslips were obtained after drying for 3 days (in a vacuum oven for the 3rd day) at 40oC. The thickness of the films was controlled by the volume of the mixture dropped on the cover slip. The coated hybrid films were obtained after drying for one day at 40oC oven and then in a vacuum oven of 60 oC for 3 days as shown in Figure 2