The functionalization of carbon nanotubes using a batch oscillatory flow reactor

Abstract

This paper describes an efficient method for the functionalizing of multi-walled carbon nanotubes (MWCNT) using oscillatory flow mixing (OFM). A 3. l batch oscillatory flow reactor (OFR) was designed and constructed for pilot scale functionalization of MWCNT in order to potentially improve their compatibility within a thermoplastic polyphenylene sulphide (PPS) matrix. The OFM batch reactor consisted of a jacketed cylindrical vessel with a vertical axial oscillator that contained a series of baffled mixing plates. MWCNTs dispersed in dimethylformamide (DMF) were introduced into the reactor and a two stage reaction for functionalizing MWCNTs with PPS compatible groups was carried out under oscillation of baffles at elevated temperatures. Fluid mixing observations in the reactor showed that MWCNTs formed a uniform dispersion of aggregated flocs before and during the functionalization reaction. On completion of the reaction and cessation of the oscillation, the aggregated flocs of MWCNT rapidly sedimented at the bottom of the reactor; hence could be collected as a concentrated mass thereby facilitating the separation of functionalized MWCNTs from the solvent. The functionalized MWCNTs were dried and then characterized by transmission electron microscopy, infrared spectroscopy as well as thermal gravimetric analysis in order to investigate the extent of MWCNT functionalization. The characterization results confirmed the effective and relatively uniform functionalization of the MWCNTs despite formation of aggregates, indicating that OFM provides a viable approach for functionalizing MWCNTs. © 2012

Oscillatory Flow Reactors (OFRs) for Continuous Manufacturing and Crystallization

“…Additionally, while the majority of these applications involved a single orifice baffle design, alternative approaches have also been considered. 178 The OFR has also been examined for continuous applications, see 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 breakage of flow axi-symmetry which was found to be related to the smaller cross-free section of the constrictions in the SPC geometry. Numerical simulations 187 The results of the study showed that the level of back-mixing was highly dependent on both f and x 0 (as with traditional ...…”

Improving flexural and dielectric properties of MWCNT/epoxy nanocomposites by introducing advanced hybrid filler system

“…Previously, a great deal of research was conducted to overcome the challenges mentioned above; i.e., to improve the dispersion of CNT in the epoxy matrix [16][17][18][19][20][21]. Most techniques deal with processing issues rather than scrutinizing the filler design aspect or architecture.…”

“…Most techniques deal with processing issues rather than scrutinizing the filler design aspect or architecture. The research included investigations of different methods such as chemical functionalization [16][17][18][19], physical blending (ultrasonication or high shear mixing) [20,21] and hybridization [22]. Chemical functionalization focuses on the surface treatment of the CNT structure to improve its chemical interaction with the polymer matrix, resulting in enhanced dispersion.…”

Experimental investigation of thermal conductivity of medical nanofluids based on functionalised single‐wall carbon nanotube and conjugated cisplatin

“…Covalent functionalisation of the CNT surface is considered as another chemical method. The most commonly used covalent functionalisation is through oxidative treatment which attaches oxidised functional groups to the CNT surface, such as carboxylic groups [14][15][16]. This increases the CNTs solubility, because of the generation of a more hydrophilic surface structure, which in turn reduces agglomeration of CNTs [17].…”