Poly(tannin urethane)-Stabilized Multiwalled Carbon Nanotube Aqueous Dispersion for Antistatic Coating

Abstract

The individually dispersed multiwalled carbon nanotubes (MWCNTs) enable the comprehensive accomplishment of intrinsic electrical conductivity, thermal conductivity, and antielectromagnetic shielding characteristics. However, the design of an aqueous carbon nanotube (CNT) dispersant remains a significant challenge in rational balances of strong interfacial interactions between CNT/dispersant and water medium. In the current research, biomass tannic acid (TA) was selected as the building block to synthesize poly(tannin urethane) (PTU) by step polymerization of TA and toluene diisocyanate, which was examined as a novel dispersant for MWCNTs. A highly homogeneous dispersion of PTU-stabilized MWCNTs and carbon black (CB) was prepared by a simple sonification and homogenization process to form aqueous antistatic additives. Furthermore, the antistatic coating for a flexible poly(vinyl chloride) (PVC) substrate was prepared by a dip-coating method using self-made waterborne polyurethane (WPU) as a binder. The results demonstrated that the aggregates of MWCNTs were successfully debundled into individually dispersed nanotubes by taking advantage of the high π−π interaction between MWCNTs and PTU. Compared with the chemical modification, the physically stabilized MWCNTs displayed fewer defects (I D /I G ∼ 0.853). Compared with the pure WPU coating, the sheet resistivity of the MWCNTs/CB/PTU/WPU coating decreased sharply from 10 16 to 10 8 Ω at 0.5 wt % loading of MWCNTs, which met the requirement of antistatic applications. With further increase of the MWCNT content, the MWCNTs/CB/PTU/WPU coatings exhibited continually decreasing sheet resistivity and reached remarkably low surface resistance of 10 4 Ω at 2.0 wt % loading of MWCNTs, which was realized by the formation of conducting networks of synergistic MWCNTs and CB-induced low percolation threshold. The facile one-pot preparation of biobased PTU and simple production of MWCNT dispersion promise an ideal additive for antistatic and conductive-related applications, especially for flexible substrates.

Synthesis ofSMA‐PEGhyperdispersant and its stabilization mechanism for carbon black

“…UV–Vis spectroscopy testing is another method to detect the dispersion stability of carbon black. At the same concentration of diluted carbon black dispersion, the peak the stronger, the more stable the dispersion 36 . As can be seen from Figure 9, the carbon black dispersion prepared from SMA3000‐MPEGA2000 shows the weakest peak, indicating the worst carbon black dispersion; while that obtained from SMA1000‐MPEGA500 and SMA3000‐MPEGA1000 shows the similar strongest peak.…”

“…At the same concentration of diluted carbon black dispersion, the peak the stronger, the more stable the dispersion. 36 As can be seen from Figure 9, the carbon black dispersion prepared from SMA3000-MPEGA2000 shows the weakest peak, indicating the worst carbon black dispersion; while that obtained from SMA1000-MPEGA500 and SMA3000-MPEGA1000 shows the similar strongest peak. This result is different from the stability sequence of the dispersant for the carbon black paste, which may be caused by the best electrostatic repulsion effect of carbon black dispersion prepared from SMA1000-MPEGA500 with the highest absolute value of zeta potential (Figure 6).…”

Highly homogeneous and stable single-walled carbon nanotubes dispersion modified by polyvinylpyrrolidone and alkanolamine in water

“…2,8,11 It is a good way to prove the surface modication effect of SWCNTs by comparing the absorbance intensity of carbon nanotubes remaining aer a centrifugation. 28,29 Therefore, the dispersing ability at varied dispersant content was characterized using UV-vis spectroscopy. As reported in previous studies, the greater absorbance proved the better dispersibility because the intensity of absorbance is related to the number of nanoparticles contained in the unit volume of the dispersion.…”

“…Supporting evidence for the non-covalent modication of commercial SWCNTs comes from the thermogravimetry analysis. 27,28 Actual SWCNTs compositions of commercial SWCNTs, P-SWCNT and PA-SWCNTs at a temperature rate of 10 °C min −1 are shown in Fig. 6.…”

Study on the Dispersion Stability and Plugging Performance of Dopamine-Modified Multiwalled Carbon Nanotubes

“…This energy is approximately 500 eV/μm . As a result, commercial MWCNTs are mostly present as solid powders of cross-linked and entangled aggregates, leading to a challenge for their homogeneous dispersion in water. , One of the keys to exploiting the excellent performance of carbon nanotubes as plugging materials in WBDFs is to solve the problem of their dispersion stability. At present, the main methods to enhance the dispersion stability of carbon nanotubes are physical dispersion (based on mechanical shear, ultrasonic dispersion, ball milling, etc.)…”