Hydrophilic treatment for strong carbon nanotube fibers

Abstract

The hydrophobic surface characteristics of carbon nanotube fibers (CNTFs) limit their usage in aqueous systems. Herein, we report a surface treatment method for preparing hydrophilic CNTFs by attaching a sulfonic acid group onto the surface of CNTF. The introduction of a sulfonic acid group was examined by x-ray photoelectron spectroscopy. The contact angle between the CNTF and water droplets decreased after a surface treatment to 22.9°, implying enhanced hydrophilicity. The nanostructure of the CNTF is rarely changed during surface treatment, so the surface characteristics can be controlled without losing the advantages of direct-spun CNTFs. Water infiltration was examined by measuring the electric double-layer capacitance of CNTFs. The capacitance of surface-treated CNTFs (140 μF cm−1) was even higher than the as-prepared CNTFs (21 μF cm−1), meaning that the interfacial area between CNTFs and water electrolytes significantly increased, and water can infiltrate effectively into the nanopores of CNTFs as a result of the surface treatment. The sulfonic acid group is more efficient than the carboxyl group in improving hydrophilicity and water infiltration. The surface treatment also enhances the specific strength of the CNTFs by 50%, which is beneficial for preparing CNTF-based devices. The hydrophilic CNTFs prepared in this work will be useful in preparing CNTF-possessing functional nanoparticles or in use in CNTFs for electrochemical devices.

All-in-one flexible supercapacitor with ultrastable performance under extreme load

“…S7 and S8) and Fourier transform infrared (FT-IR; Fig. 3C) spectra, carboxylic groups were introduced on the surface of DWNTY via diazotization using p-aminobenzoic acid while maintaining original properties of DWNTY (table S2, denoted as mDWNTY) (27)(28)(29). X-ray diffraction (XRD) patterns also confirmed that diazotization functionalized the surface of DWNTY without change in graphitic structure (fig.…”

Hydrophilic and Conductive Carbon Nanotube Fibers for High-Performance Lithium-Ion Batteries

“…We prepared raw CNTF and surface-modified CNTF as conductive platform materials to grow SnO 2 nanoparticles. The surface-modified CNTF was prepared by the diazotization method reported in previous works with further optimization [13,20]. We manipulated the degree of functionalization by changing the concentration of the sulfanilic acid to find optimum CNTF.…”

“…We introduced sulfonic acid groups on the raw CNTF by a diazotization method, as we reported before [13,20]. The diazonium ions were prepared by a reaction of 0.025-0.3 M of sulfanilic acid (Sigma Aldrich, Burlington, MA, USA) and an equivalent amount of sodium nitrite (NaNO 2 , Sigma Aldrich) in 1 M HCl.…”

“…Therefore, enhancing the hydrophilicity of the CNTF by surface functionalization is necessary for preparing active materials-incorporated CNTF in an aqueous system. Recently, we reported a surface modification method for CNTF to improve the hydrophilicity of the fibers [13]. In particular, sulfanilic acid groups were more effective than the carboxyl group to enhance the hydrophilicity of CNTF.…”

Identification of fatigue damage modes for carbon fiber/epoxy composites using acoustic emission monitoring under fully reversed loading

“…Compared with traditional metal materials, this material has the advantages of high strength, high rigidity, lightness, fatigue resistance, corrosion resistance, and material performance designability. [ 1–3 ] The customizable laminate structure provides brilliant mechanical properties for diverse application scenarios by changing the stacking sequence and related fiber orientation. Ahmadzadeh et al [ 4 ] developed a stiffness‐based model to characterize the progressive fatigue damage in quasi‐isotropic carbon fiber‐reinforced polymer (CFRP) [90/±45/0] composite laminates with various stacking sequences.…”