Oxidation functionalization of multiwalled carbon nanotube by mild acid sonication

Abstract

Multiwalled carbon nanotube (MWCNT) has excellent properties in thermal and electrical conductivities, high tensile strength and surface area and low mass over volume. However, the usage is still limited due to its inert characteristic. MWCNT surface is hydrophobic and not miscible in most solvents. This work emphasize on simple and practical method of functionalization by sonication in mild acid condition. 6M of Nitric acid and Sulfuric acid mixture (Method I) and 6M of Nitric acid (Method II) were demonstrated as an oxidizing agent to introduce carboxyl functional group on MWCNTs surface. Both type of functionalization has demonstrated carboxyl formation but functionalization in acid mixture was chosen to be used for further study for aptamer immobilization. FTIR and SEM have been used to investigate the binding properties and surface morphology respectively. The functionalization time has also been studied by using dispersability test which resulted in good dispersion after 1 hour of functionalization.

Electrospray flow rate influenced the sized of functionalized soot nanoparticles

“…Sahoo and Kandasubramanian reported that the wettability properties of soot particles significantly influenced by the presence of certain functional groups such as C─H and C═O groups that will show a hydrophobic and hydrophilic property, respectively. The presence of carboxylic groups on the soot surface that is proven in the FTIR result will form a hydrogen bond with water molecules and thus reduce the water contact angle and give superhydrophilic property to the functionalized soot …”

“…Covalent functionalization occurred when the functional group shared an electron with soot to form a bond. The covalent functionalization will change the state of carbon from sp 2 to sp 3 orbital thus changing its properties . An oxidizing agent such as hydrochloric acid, nitric acid, or a mixture of sulfuric acid and nitric acid was used during the acid oxidation process .…”

The effect of spray volume and height to the electrical conductance of carbon nanotube layer

“…Functionalization of MWCNT usually turned the material hydrophilic with additional oxygenated species on the surface. The functionalization process was conducted by oxidizing the MWCNT in nitric and sulfuric acid mixture (1:3) while sonicated for 4 hours to generate carboxyl functional group [9]. The usage of dispersing solvent is the most important thing in the spray coating technique.…”

Surface Functionalization of Carbon Nanotubes for Energy Applications

“…Surface Functionalization of Carbon Nanotubes for Energy Applications DOI: http://dx.doi.org /10.5772/intechopen.84479 catalyst, or hydrofluoric acid) under ultrasonic treatment conditions [5][6][7]. The oxidation-functionalization process usually produces small CNT fragments with sidewalls containing different oxygen functional groups (e.g., hydroxyl, carbonyl, and carboxylic acids) [8] that will be able to create covalent bonding with other groups (e.g., polymeric reagents, metal oxides, amino acids, and enzymes) (see Figure 3) [9].…”