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Carbon nanomaterials are ideal fillers in composites for electrothermal applications due to their ultrahigh electrical conductivity, thermal conductivity, and excellent mechanical property. In this study, high-performance electrothermal laminate films were prepared by a layer-by-layer process, which used tannic acid-functionalized multiwalled carbon nanotubes as filler and thermoplastic polyurethane as substrate. The prepared electrothermal laminate films exhibit excellent mechanical property, electrical heating property, and high electrothermal performance, which can reach steady-state temperature in about 120 s. Additionally, the maximum steady-state temperature can reach ∼150 °C at 20 V. During 10 different cycles of experiments and 5 h aging time, no significant change in temperature was observed. Moreover, from the results, it is clear that the performance of the samples is related to the amount of filler added and the applied voltage, and we can precisely control the sample performance by regulating the amount of filler addition and applied voltage. We believe that these electrothermal laminate films could be widely used in wearable heating cotton fabric, controllable electric heating module, floor heating, and deicing devices.

Graphene oxide (GO), reduced graphene oxide (rGO) and carbon nanotubes (CNTs) have their own advantages in electrical, optical, thermal and mechanical properties. An effective combination of these materials is ideal for preparing transparent conductive films to replace the traditional indium tin oxide films. At present, the preparation conditions of rGO are usually harsh and some of them have toxic effects. In this paper, an SnCl2/ethanol solution was selected as the reductant because it requires mild reaction conditions and no harmful products are produced. The whole process of rGO preparation was convenient, fast and environmentally friendly. Then, SEM, XPS, Raman, and XRD were used to verify the high reduction efficiency. CNTs were introduced to improve the film conductive property. The transmittance and sheet resistance were the criteria used to choose the reduction time and the content ratios of GO/CNT. Thanks to the post-treatment of nitric acid, not only the by-product (SnO2) and dispersant in the film are removed, but also the doping effect occurs, which are all conducive to reducing the sheet resistances of films. Ultimately, by combining rGO, GO and CNTs, transparent conductive films with a bilayer and three-dimensional structure were prepared, and they exhibited high transmittance and low sheet resistance (58.8 Ω/sq. at 83.45 T%, 47.5 Ω/sq. at 79.07 T%), with corresponding $${{\sigma_{dc} } \mathord{\left/ {\vphantom {{\sigma_{dc} } {\sigma_{opt} }}} \right. \kern-\nulldelimiterspace} {\sigma_{opt} }}$$ σ dc / σ opt values of 33.8 and 31.8, respectively. In addition, GO and rGO can modify the surface and reduce the film surface roughness. The transparent conductive films are expected to be used in photoelectric devices.

Wrinkled p-phenylenediamine (PPD)-functionalized graphene oxide (PGO) is synthesized, characterized, and subsequently incorporated in a ethanol-based polyvinyl butyral (PVB) film (ca. 10 μm thick). The anti-corrosive properties of the pure PVB and nanocomposite (PVB-PGO and PVB-GO) films are tested on steel and compared. Electrochemical impedance spectra reveal that the PGO-reinforced PVB nanocomposite film exhibits the slowest corrosion rate (4 × 10−4 mm a−1 after a 20-day immersion) among the samples, and the results of 7-day saline spray bombardment tests show it is the most robust and durable. The PVB-PGO coating protects the steel substrate from visible corrosion. Incorporation of GO in the PVB matrix results in a reduction of the PVB film anti-corrosion properties. However, by functionalizing GO with PPD, highly dispersible wrinkled PGO flakes are obtained, thus leading to a uniform film that presents a highly tortuous path for impeding liquid and gas molecules. The PVB-PGO nanocomposite film exhibits high, stable capacitance without film delamination, cracking, or other visible damage. Readily accessible as a simple and environmentally friendly, this approach may present an advantageous strategy for creating protective coatings in marine and other applications. PGO with wrinkle structure, as nanometer reinforcing materials in PVB coatings, improved the corrosion resistance of the coatings by extending the permeation path of the corrosive medium.

Herein, we demonstrated for the first time the green fabrication of graphene by wet ball milling method which utilizes natural honey as exfoliation medium, further the 3D conductive networks (Graphene/Carbon nanotubes/PEDOT:PSS, G/CNT/PEDOT:PSS) were integrated into the biodegradable Starch/Chitosan/Poly vinyl alcohol (S/C/PVA) substrates. This electrode possesses an excellent optoelectronic performance (Rs = 43.2 Ω/sq., T = ca. 80% at 550 nm), and a very low Root Mean Square (RMS) roughness (approximately 1.38 nm). The sheet resistance of the films changed slightly after 1000 bending cycles and adhesion tests. The flexible green light OLED using G/CNT/PEDOT:PSS-S/C/PVA film as anode was successfully fabricated, the luminance of the device was 5701 cd/m2 at 15 V and the maximum current efficiency was 3.75 cd/A at 13 V. Moreover, this new type of OLED device degrades gradually within 10 min in 2 wt% lysozyme CH3COOH solution, which could be used to prepare the next generation of user-friendly, eco-friendly flexible wearable electronic devices.

The research and preparation of excellent anti-corrosion coatings is still a difficult task and critical to practical applications. In this paper, phosphoric acid, dodecylbenzenesulfonic acid (DBSA), and polyaniline (PANI) were polymerized in-situ onto graphene oxide (GO) by the one-pot method to prepare dodecylbenzenesulfonic acid-PANI/phosphorylated graphene oxide (DPPGO). The results of TEM, FTIR, Raman spectrum, XRD, TGA, and XPS analysis showed that the DPPGO was successfully prepared. The SEM observations showed that DPPGO has best dispersibility and compatibility than GO and PANI/phosphorylated graphene oxide (PPGO) in waterborne polyurethane (WPU) matrix. To achieve anti-corrosion performance, a new type of graphene-based polymer nanocomposites water-based coating was developed and tested by electrochemical measurements. Through a series of electrochemical tests, it is concluded that the anti-corrosion performance of a composite coating DPPGO is significantly improved. The excellent anti-corrosion properties are due to the perfect dispersion and good compatibility of DPPGO in WPU.

Carbon nanotubes (CNTs) and graphene oxide (GO) were sprayed on flexible polyethylene terephthalate (PET) substrates to prepare CNT and GO–CNT transparent conductive films (TCFs). For the GO–CNT TCFs, when the mass ratio of GO to CNTs was 0.2, a relatively low sheet resistance of 90.4 Ω sq−1 at a transmittance of 87% (550 nm) was obtained with an average σdc/σopt value of 28.9. Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) solution without or with ethylene glycol (EG) added was sprayed on the surface of the GO–CNT films to obtain P/GO–CNT and P(E)/GO–CNT films, respectively. P(E)/GO–CNT films were post-treated with sulfuric acid to obtain P(E,S)/GO–CNT TCFs. The addition of PEDOT:PSS can permeate into the pores of networks and densify the GO–CNT networks, increasing the conductivity and wettability and decreasing the roughness of the films. Additional EG can reduce the Coulomb force between PEDOT and PSS and change the morphology of PEDOT, and at the same time sulfuric acid treatment can effectively remove PSS from the PEDOT:PSS layer. The P(E,S)/GO–CNT 0.2 TCFs exhibited a sheet resistance of 46.3 Ω sq−1 at a transmittance of 87.5% (550 nm) with an average σdc/σopt value of 56.1. The organic light emitting diodes were successfully fabricated, and the mechanism of how the electrical conductivity of the hybrid film increased was also investigated.

The amphiphilic graphene derivative was prepared by covalent grafting of graphene oxide (GO) with isophorone diisocyanate and N,N-dimethylethanolamine and then noncovalent grafting of GO with sodium dodecylbenzenesulfonate. The results obtained from infrared spectroscopy, X-ray photoelectron spectroscopy, thermal gravimetric analysis, and X-ray diffraction analysis revealed that the short chains were successfully grafted onto the surface of GO. Subsequently, scanning electron microscopy and optical microscopy results showed that the modified GO (IP-GO) has the best dispersibility and compatibility than GO and reduced GO in the waterborne polyurethane matrix. The relationship between the corrosion resistance of composite coatings and the dispersibility of the graphene derivative and the compatibility of the graphene derivative with a polymer matrix were discussed. The anticorrosive properties were characterized by electrochemical impedance spectroscopy analysis and salt spray tests. Through a series of anticorrosion tests, it is concluded that the anticorrosion performance of a composite coating with 0.3 wt % IP-GO is significantly improved. The excellent anticorrosion performance is due to the perfect dispersion and good compatibility of IP-GO in waterborne polyurethane.

Strawberry is one of the most highly consumed fruits worldwide, but is extremely perishable. This study systematically compared the effects of chitosan, sucrose, glucose, and fructose immersion on the physiology and disease development in harvested strawberries. After storage at 15 °C for 9 days, all sugar treatment groups had significantly higher total soluble solids and total anthocyanin content than those of the control group. All sugar treatment groups inhibited malondialdehyde accumulation. At the end of the storage, chitosan, glucose, and fructose maintained higher superoxide dismutase activity and chitosan maintained higher catalase activity. The chitosan and glucose groups had lowest fruit decay index, followed by sucrose and fructose groups. The fruit firmness and luster were better maintained in the glucose group. Furthermore, genes related to sucrose metabolism (e.g., FaSUS1 and FaSUS2), titratable acidity accumulation (e.g., FaMDH1, FaMDH2, FaCS1, and FaCS2), disease resistance (e.g., FaPGIP1, FaWRKY1, and FaWRKY33) and to anabolic jasmonic acid and abscisic acid pathways (e.g., FaJAZ1, FaJAZ2, FaOPR3, FaNCED1, and FaNCED2) were regulated to varying degrees, suggesting that chitosan and glucose participate in plants’ immune signaling networks and regulate disease resistance in fruit through hormone pathways. The findings provide new insights into the physiological regulation of harvested strawberries.

Membrane fouling is an inevitable aspect of water treatment that severely limits membrane performance. Therefore, simple and effective membrane fouling monitoring methods are highly sought after to assess the level of fouling before damage occurs or membrane replacement is necessary. Here, conductive blended ultrafiltration (UF) membranes prepared by blending conducting polyaniline (PANI) nanofibers and multi-walled carbon nanotubes (MWCNTs) in a polysulfone (PSF) matrix were applied to an online fouling monitoring system. The UF blended membranes with higher porosity and larger pores than the pristine PSF membrane exhibited higher conductivity and water flux (196 L m−2 h−1). An in-house crossflow cell connected to an electrochemical workstation was used to measure the resistance by linear sweep voltammetry (LSV) in order to monitor the fouling process. The blended UF membrane simultaneously achieved a bovine serum albumin (BSA) rejection of 94.2% and a significant resistance drop in response to BSA pollutant caking. It is the first study to monitor fouling using LSV. Exploring the relationship and trends between the permeate flux and membrane resistance provided a theoretical basis for practical applications and enabled online monitoring of the degree of pollution, demonstrating promising potential for industrialization.

Carbon nanotubes (CNTs) and poly(3,4-ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS) were employed to prepare sandwich-structured CNT/PEDOT:PSS/CNT transparent conductive films (TCFs) on flexible polyethylene terephthalate (PET) substrate by a spraying method. Based on the film morphology, we suggest that the CNTs were embedded in PEDOT:PSS. The structured film was more stable and did not peel off during post-processing nitric acid treatment. Ethylene glycol (EG) was used to improve the conductivity of the film, and the best ratio of PEDOT:PSS to EG was 10:5. XPS and Raman spectroscopy studies revealed that the non-conductive sodium dodecylbenzene sulfonate and PSS were removed during the nitric acid treatment. TCF sheet resistance as low as 95.15 Ω/sq at 87.72% transmittance (at a wavelength of 550 nm) was obtained. When the CNT/PEDOT:PSS/CNT-TCF was used as an anode in an organic light emitting diode, the high luminance of the device was 1598 cd/cm2 at 14 V, and the maximum current efficiency was 1.5 cd/A at 13 V.

Transparent conductive films (TCFs) were fabricated via a spray-coating method with a solution prepared by dispersing single-walled carbon nanotubes (SWCNTs) in deionized water with sodium dodecylbenzene sulfonate (SDBS) as surfactant. We explored the mechanism of HNO3 treatment by treating TCFs with different reagents. After being treated with different concentrations of reagents by HNO3, HCl, and NaNO3 to lower the sheet resistance of TCFs, the properties of TCFs were further characterized by a UV-VIS spectrophotometer, a four-point probe method, atom force microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. In this study, we conclude that the HNO3 treatment results in a decrease in the sheet resistance of the TCFs due to the combined effect of acidity and oxidizability. The strong interaction of the strong acidity and strong oxidizing property of HNO3 causes the SDBS to be removed. To further improve the film conductivity of the TCFs, the experimental conditions of the HNO3 treatment were optimized.

WRKY genes and jasmonic acid (JA) play a crucial role in plants&rsquo, responses against biotic and abiotic stress. However, the regulating mechanism of WRKY genes on strawberry fruits&rsquo, resistance against Botrytis cinerea is largely unknown, and few studies have been performed on their effect on the JA-mediated defense mechanism against B. cinerea. This study explored the effect of FaWRKY25 on the JA-mediated strawberry resistance against B. cinerea. Results showed that the JA content decreased significantly as the fruits matured, whereas the FaWRKY25 expression rose substantially, which led to heightened susceptibility to B. cinerea and in strawberries. External JA treatment significantly increased the JA content in strawberries and reduced the FaWRKY25 expression, thereby enhancing the fruits&rsquo, resistance against B. cinerea. FaWRKY25 overexpression significantly lowered the fruits&rsquo, resistance against B. cinerea, whereas FaWRKY25 silencing significantly increased resistance. Moreover, FaWRKY25 overexpression significantly lowered the JA content, whereas FaWRKY25 silencing significantly increased it. FaWRKY25 expression level substantially affects the expression levels of genes related to JA biosynthesis and metabolism, other members of the WRKY family, and defense genes. Accordingly, FaWRKY25 plays a crucial role in regulating strawberries&rsquo, resistance against B. cinerea and may negatively regulate their JA-mediated resistance mechanism against B. cinerea.

Membrane fouling limits membrane performance and membrane applications. Changing the membrane surface properties may effectively alleviate membrane fouling. Preparing conductive membranes is an efficient way to achieve this goal. In this paper, the polypyrrole–carbon nanotube/polyethersulfone composite membranes (PPy–CNT/PES) were successfully fabricated via a process of chemical polymerization of pyrrole on the CNT/PES substrate. The resistivity, pure water flux, as well as the fouling prevention performance of the PPy–CNT/PES membrane were systematically studied. The electric resistance of the PPy–CNT/PES membrane was greatly reduced to 450 ± 40 Ω cm-1, and the pure water flux for the PPy–CNT/PES membrane was about 136.2 ± 5.1 L m− 2 h− 1 bar− 1. The flux recovery rate of the PPy–CNT/PES membrane was increased from 68.18 to 76.38% compared with the pristine PES membrane. An electric field of 1 V/cm was applied between the titanium sheet and the PPy–CNT/PES membrane as a cathode, and the flux recovery rate of the PPy–CNT/PES membrane was improved to 81.78%. Therefore, the membrane cathode could effectively prevent the pore clogging, meaning that the prepared PPy–CNT/PES membrane has significant potential for practical applications in anti-fouling.

Soil salinity is one of the major factors that affect plant growth and decrease agricultural productivity worldwide. Chitosan (CTS) has been shown to promote plant growth and increase the abiotic stress tolerance of plants. However, it still remains unknown whether the application of exogenous CTS can mitigate the deleterious effects of salt stress on lettuce plants. Therefore, the current study investigated the effect of foliar application of exogenous CTS to lettuce plants grown under 100 mM NaCl saline conditions. The results showed that exogenous CTS increased the lettuce total leaf area, shoot fresh weight, and shoot and root dry weight, increased leaf chlorophyll a, proline, and soluble sugar contents, enhanced peroxidase and catalase activities, and alleviated membrane lipid peroxidation, in comparison with untreated plants, in response to salt stress. Furthermore, the application of exogenous CTS increased the accumulation of K+ in lettuce but showed no significant effect on the K+/Na+ ratio, as compared with that of plants treated with NaCl alone. These results suggested that exogenous CTS might mitigate the adverse effects of salt stress on plant growth and biomass by modulating the intracellular ion concentration, controlling osmotic adjustment, and increasing antioxidant enzymatic activity in lettuce leaves.

Improved OLED systems have great potential for next-generation display applications. Carbon nanotubes (CNTs) and the conductive polymers poly (3,4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS) have attracted great interest for advanced applications, such as optoelectronic products. In this paper, the simultaneous enhancement of the conductivity, roughness, and adhesion properties of transparent conductive films with PEDOT: PSS/CNTs is reported. These films prepared by a simple spin-coating process were successfully used to produce high-performance organic light-emitting diodes (OLEDs) with an improved lifetime. Addition of PEDOT: PSS lowered the film sheet resistance and CNTs helped to enhance the stability and maintain the lifetime of the OLEDs. In addition, treatment with methanol and nitric acid changed the morphology of the polymer film, which led to greatly reduced sheet resistance, enhanced substrate adhesion, and reduced film roughness. The best performance of the film (PEDOT: PSS: CNT = 110: 1, W/W) was 100.34 Ω/sq.@ 90.1 T%. High transmittance, low sheet resistance, excellent adhesion, and low roughness (3.11 nm) were achieved synchronously. The fabricated OLED demonstrated a low minimum operating voltage (3 V) and could endure high voltage (20 V), at which its luminance reached 2973 cd/m2. Thus, the incorporation of CNTs within PEDOT: PSS electrodes has great potential for the improvement of the performance of OLED devices.

To enhance the anti-fouling performance of polysulfone (PSF) membranes, polyaniline (PANI) nanofibers were used as additives in a facile method to prepare PANI/PSF blended membranes (PPMs). The fouling behavior between the membrane and natural organic matters (NOM) pollutant was further analyzed by implementing extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) theory. Overall, the performance of the PPMs was improved in comparison with that of the pristine PSF membrane. The pure water flux of the PPM increased to 2.4 times that of pristine PSF, reaching up to 169 L·m−2 h−1 bar−1. The tensile strength of the hybrid membranes also increased after the incorporation of PANI nanofibers. In particular, in anti-fouling measurement, the PPMs exhibited enhanced anti-fouling properties for filtration serum albumin (BSA), humic acid (HA) and sodium alginate (SA) solutions. The anti-fouling mechanism was analyzed by the interfacial interaction energy, which were obtained by applying the XDLVO theory. Results confirmed that there are reduced attractive interaction energies between the PPMs and NOM pollutants molecules in comparison to the interaction between the pristine PSF and NOM pollutants molecules.

Flexible transparent conducting films (TCFs) with carbon nanotubes (CNTs) have attracted more and more attention for their wide range of potential applications. While, there are still some problems to be solved on several aspects. In this study, a graphene oxide/carbon nanotube (GO/CNT) hybrid TCF was fabricated through the simple spray coating method. GO sheets were introduced to form new electron transporting channels. It was found that the best optoelectronic property films were fabricated when the ratio of GO/CNT is 1.5:1.0, which the sheet resistance of the film was found to be 146 Ω/sq at the transmittance of 86.0%. Due to the two-dimensional structure and the oxidation groups of GO sheets, flatness and wettability of the electrode surface was improved obviously. Adhesion factor of the TCFs was calculated by the change of transparent and sheet resistance after trial test, the addition of GO sheets enhanced the adhesion dramatically and the mechanism was analyzed. Improvements of conductivity, flatness, wettability and adhesion above are all advantageous for the solution-based processing of organic electronics for spraying and printing.

Antistatic technology has been applied in all aspects of modern life, including the manufacture of electronic products, aerospace systems, daily necessities and so on. The main purpose of this study is to obtain, using the Mayer rod-coating method, a flexible antistatic film with high transmittance, low sheet resistance and strong adhesion. With the help of the dispersant, single-walled carbon nanotubes (SWCNTs) were dispersed in water to form an homogeneous dispersion. The SWCNT dispersion was coated onto a poly(ethylene terephthalate) (PET) film with use of a rod to produce a uniform film. The antistatic films obtained had special characteristics, such as high transparency, low sheet resistance and excellent resistance to water and heat. Sheet resistance varied between 102–105 Ω sq−1 by controlling the content of water-based polyurethane (WPU), changing the thickness of the films and the post-treatment. The best film had a sheet resistance of 423 Ω sq−1 with 82.7% transmittance. In particular, the addition of the WPU binder greatly improved the adhesion between the CNTs and the PET film. Scanning electron microscopy, energy dispersive X-ray spectroscopy and Scotch™ tape method were conducted to determine the microstructure, cleanliness, and adhesion of the film, respectively.

Membrane fouling can be effectively addressed by modifying the membrane to realize anti-fouling capability together with real-time fouling detection. Here, we present the synthesis and water treatment testing of a promising candidate for this application, a composite membrane of polyvinylidene fluoride (PVDF) and functionalized carbon nano-materials prepared by a facile phase inversion method. The synergistic effect of oxidized multi-walled carbon nanotubes (OMWCNTs) and graphene oxide (GO) enabled better surface pore structures, higher surface roughness, hydrophilicity, and better antifouling property as compared with that of pristine PVDF membranes. The PVDF/OMWCNT/GO mixed matrix membranes (MMMs) achieved a high water flux of 125.6 L m−2 h−1 with high pollutant rejection rate, and their electrical conductivity of 2.11 × 10−4 S cm−1 at 100 kHz was sensitive to the amount of pollutant uptake. By using hybrid MMMs, we demonstrate simultaneous pollutant filtering and uptake monitoring, which is an important step in revolutionizing the water treatment industry.

The purpose of this study was to evaluate the role of proline in relieving the growth inhibition of lettuce grown under low potassium conditions. Lettuce was hydroponically grown in a half-strength Enshi formula nutrient solution containing 2 mM K+ and treated with exogenous prolines (0.5, 1.0, 1.5, and 2.0 mM). The results revealed that exogenous proline applications with 1.0 and 1.5 mM alleviated oxidative damage in lettuce leaves, as demonstrated by lower lipid peroxidation and hydrogen peroxide concentrations, together with an increased activity of antioxidant enzymes. Additionally, the application of 1.0 or 1.5 mM proline enhanced the levels of proline, soluble sugars, and ascorbic acid in leaves compared with lettuce grown under low potassium condition. The growth analysis results suggest that addition of 1.0 and 1.5 mM exogenous proline increased the relative growth rate, mainly by increasing the leaf area ratio. To a lesser extent, this growth was caused by an increase in the net assimilation rate. We proposed that the application of proline in certain concentrations could increase the yield and quality of lettuce through regulating the biochemical process of plants under low potassium conditions.

Organic films and coatings, specifically those incorporating graphene oxide, offer many advantages as corrosion barriers due to the excellent shielding and tailorable characteristics of graphene oxide. A simple method was used to prepare a composite coating with polyurethane (PU) as a polymer matrix; gallic acid modified graphene oxide (FGO) flakes and acidified multi-walled carbon nanotubes (FMWCNTs) acted as nanoscale reinforcement. The presence of FMWCNTs improved the dispersion of FGO in PU, and the composite coating exhibited nearly no defects. The one-dimensional FMWCNTs and two-dimensional graphene oxide sheets attract each other to form a relatively stable layered structure, such that the graphene oxide sheets form a large shielding layer. The anticorrosion properties of the pristine PU and composite coatings were investigated by electrochemical impedance spectroscopy tests for 96 h. The composite coating reinforced by two carbon nanomaterials simultaneously underwent no corrosion after immersion for 96 h, and the corrosion resistance was better than that of the other coatings. The enhanced anticorrosion properties of the FMWCNT-FGO/PU composite coating are attributed to the fully exploited reinforcement effect from the network of FGO and FMWCNTs that is enabled via enhanced dispersion.

High-performance, flexible film heaters with carbon nanotube transparent conducting films are easily fabricated by both a rod-coating method and a spraying method. The main conclusion we have reached is that the film demonstrates a heating rate of 6.1°C s −1 at 35 V and sheet resistance as low as 94.7 Ω sq −1 with 72.04% optical transmittance at a wavelength of 550 nm by the spraying method after a series of post-treatment processes with acid and distilled water. Then, we adopt a mathematical method of nonlinear fitting to simulate the collected experimental data and the functions effectively. Furthermore, through analysis of the formula, the correlation between temperature and time is well explained. Therefore, carbon nanotube-based, flexible, transparent heaters exhibit high electrothermal performance and are expected to find different applications, e.g. various functional devices such as heating materials, heatable smart windows or dining tables.

In this paper, nanocomposite electrodes for rechargeable Lithium-ion battery composed of tin dioxide (SnO2) and multi-walled carbon nanotubes (MWCNTs) were prepared using the chemical deposition method with a subsequent sintering process. The as-prepared hybrids were characterized by thermal gravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction and transmission electron microscopy. The results showed that the size of pure SnO2 particles was ∼5 nm and hybrids presented a uniform dispersion of SnO2 nanoparticles on the surfaces of the MWCNTs. The electrochemical properties of the composites were researched through a cyclic voltammetry and a galvanostatic charge–discharge test. It was found that the electrochemical performance of the composite was strongly dependent on the content of MWCNTs in the composites. The SnO2/MWCNT composite with 18.40 wt% MWCNTs gave the best performance, exhibiting a relatively higher reversible capacity of 475 mAh g−1 and an extended capacity retention of 65% even after 30 cycles at a current density of 78.2 mA g−1.

Morphology-controllable carbon nanocoils (CNCs) are synthesized by thermal chemical vapor deposition using Ni nanoparticle as catalyst prepared by spray-coating method. It is found that, with the increase of number of spray-coating times, the helicity of CNCs increases whereas the average line diameter and coil pitch decrease. Additionally, infrequent Y-junction CNCs and plait-like CNCs are found in the deposits. What is noteworthy is that, compared with dip-coating, spray-coating method can prepare more uniform catalyst on substrate, resulting in more CNCs with high purity.

In this study, a hydrophobic and thermostable amine-modified graphene oxide (MGO) material was fabricated using two different methods. p-Toluidine was covalently introduced onto the surface of graphene oxide (GO) sheets using direct and indirect amidation processes to obtain the amine-modified GO (MGO-1 and MGO-2). Successful grafting of p-toluidine at the graphitic framework of graphene oxide was confirmed using infrared spectroscopy and ultraviolet-visible spectroscopy. X-ray photoelectron spectroscopy showed the simultaneous reduction and modification. The reduced weight loss, increased initial decomposition temperature and enhanced residue formation indicate significant improvement of the thermal stability of MGO compared to GO. In addition, MGO-2 has greater thermostability and hydrophobic properties than MGO-1, with a water/air contact angle of ∼126.4°. The hydrophobic and thermostable MGO material could be applied to separate organic contaminants from water, which has great potential in environmentally friendly, low-cost advanced liquid–liquid separation or water treatment technologies.

Single-walled carbon nanotubes (SWCNTs) were dispersed in water with the help of a combination of surfactants to achieve a high concentration SWCNT ink. Transparent conducting films (TCFs) were fabricated through a rod-coating method using the SWCNT ink. The addition of binders (polyacrylic acid or carboxymethyl cellulose) greatly enhanced the adhesion of SWCNT films to substrates and the cohesion between CNTs, which produced a uniform film of SWCNTs by preventing damage during the post-treatment process. The thickness of SWCNT films is controlled by the amount of SWCNTs in the solution and the diameter of the wire used. To test the film adhesion, Scotch™ tape was used to detach some loosely bound SWCNTs. Then the SWCNT films were further post-treated with nitric acid to improve the conductivity. The addition of polyacrylic acid to the SWCNT dispersion improved the film adhesion obviously without decreasing its electrical conductivity. This rod-coating method demonstrates great potential for the scalable fabrication of flexible SWCNT-TCFs.

Here a novel technique was employed to fabricated three-dimensionally porous polystyrene (PS) films via ultrasound assisted template method. In contrast to spin-coated thin film, different morphologies appeared on the films prepared by casting PS/toluene solution on glass substrates. By varying either systematic parameters or intrinsic parameters, surface structures changed from two-dimension flat pores to three-dimension sponge pores. The influences of ultrasonic intensity, frequency, irradiation time, film thickness and toluene content in water bath on surface morphologies were extensively studied. Scanning electron microscopy and white-light confocal microscopy showed that PS casted films with thickness of 200μm have a higher porosity and lower surface roughness within micrometer range. The contact angle measurement indicated slight changes of surface hydrophilicity with toluene content in water bath. Suitable toluene content favored multilayer formation of PS film and led to monodisperse pore distribution analyzed by ImageJ.

Graphene oxide (GO) is typically synthesized by graphite powder under strong oxidizing reaction, possessing with the same set of functional groups: epoxy and hydroxyl in basal plane and carboxyl and hydroxyl groups existence on the flake edges which endow GO with amphipathy. GO and its functionalized derivatives have been successfully tested in many domains, such as polymer composites, biosensors, drug delivery systems, etc. In this paper, GO was prepared by a modified Hummers method employing improved process (preparation and separation), aiming at industrialization with the lowest cost. Moreover, some novel functional groups with different properties were controlled chemically grafted onto GO to modify the wettability and reaction activity with other materials. The hydrophobicity and the thermal property of graphene oxide were enhanced by chemical functionalization.

This study introduced an innovative method to fabricate flexible transparent conducting films (TCFs) by spraying single-walled carbon nanotubes (SWCNTs) solution, dispersed by sodium dodecyl benzene sulfonate (SDBS), on polyethylene terephthalate (PET) substrate. The PET substrates were pretreated with nitric acid to improve the surface hydrophilicity. The films were spray deposited on the pretreated PET substrates in a two-step spray coating method. The film conductivity was further improved by nitric acid. As a convenient process, ultrasonication resonance method was applied to test the adhesion of TCFs. Comparing with the traditional preparation method, the adhesion of TCFs was enhanced and the mechanism was analyzed. The morphologies and thicknesses of TCFs were characterized by scanning electron microscopy and atomic force microscopy, while the Raman spectroscopy confirmed the structures of SWCNTs and the thickness changes of TCFs treated with different ultrasonication time.

A gas-fired coal preheating (GFCP) technology, offering a flexible method to reduce NOx, could be used with other de-NOx combustion technology such as air staging to seek maximum NOx reduction. The preheating chamber key apparatus of GFCP was investigated with the help of infrared camera. The results show that devolatilization and partial oxidation (combustion) of coal occurred in the preheating chamber, and this may prove the main heat source of preheating chamber is combustion of coal volatiles and gas is only used to prevent flameout. A self-sustaining combustion drop furnace was used to investigate the NOx reduction potential of GFCP with air staging. Gas species concentrations along furnace are plotted for several runs, offering details to further study and analyze the GFCP. With GFCP, much HCN, CiHj, and soot were produced in the preheating chamber, so under the similar air staging condition, the NO destructed by HCN and soot was stronger than that without. NOx reduction could archive up to 72% with...

Single-walled carbon nanotubes were dispersed in deionized water with sodium dodecyl benzene sulfonate as surfactant. The solutions were sprayed on UV and plasma treated polyethylene terephthalate to achieve transparent conductive films with excellent adhesion. The carbon nanotube films were further treated with different concentrations of nitric acid to improve conductivity. SWCNTs and films were characterized by thermo gravimetric analysis, field-emitting scanning electron microscopy, UV-VIS spectrophotometer, four-point probe method, and Raman spectroscopy. The results demonstrated that the conductivity of carbon nanotube films with high transparency was improved to a greater degree with higher concentration of nitric acid due to effectively removing residual surfactants. The low sheet resistance films of ~100 Ω/sq @ 80T% have widely applications in touch screen, flat panel displays, organic light emitting diode, and etc.

In our study, air oxidation together with three different procedures for purifying single-walled carbon nanotubes (SWCNTs) was investigated. High purity SWCNTs were obtained. The purified SWCNTs were dispersed into four different types of dispersants and different ratio of SWCNTs to dispersant was evaluated in order to find the optimal condition. Transparent conducting films were fabricated by the purified and well dispersed SWCNT solution. Nitric acid concentration was optimized to enhance the film conductivity. SWCNT films with low sheet resistance and high transmittance were obtained by nitric acid treatment.

Nanodispersion of single-walled carbon nanotubes (SWCNTs) have been systematically investigated with the use of sodium dodecyl sulfate (SDS) and poly(vinylpyrrolidone) (PVP) surfactant in deionized water. A high concentration of nanodispersed SWCNTs up to 0.08 mg/mL was achieved with introduction of an additional dispersant of PVP by optimizing surfactant concentration, sonication time, and centrifugation speed, which was crucial to obtaining a high concentration of SWCNTs in the supernatant solution. We also demonstrate that diameters of the nanodispersed nanotubes can be sorted out by controlling the centrifugation speed, and furthermore, the saturated SWCNT concentration was nearly constant, independent of the initial concentration at high centrifugation speed. Two dispersion states were identified depending on the centrifugation speed: (I) an intermediate mixed state of nanodispersion and macrodispersion and (II) nanodispersion state. This was verified by Raman spectroscopy, scanning probe microscopy,...

We investigated the modulation of optical properties of single-walled carbon nanotubes (SWCNTs) by AuCl 3 doping. The van Hove singularity transitions (E 11 (S), E 22 (S), E 11 (M)) in absorption spectroscopy disappeared gradually with an increasing doping concentration and a new peak appeared at a high doping concentration. The work function was downshifted up to 0.42 eV by a strong charge transfer from the SWCNTs to AuCl 3 by a high level of p-doping. We propose that this large work function shift forces the Fermi level of the SWCNTs to be located deep in the valence band, i.e., highly degenerate, creating empty van Hove singularity states, and hence the work function shift invokes a new asymmetric transition in the absorption spectroscopy from a deeper level to newly generated empty states.

The effect of surfactant in dispersing single-walled carbon nanotubes (SWCNTs) to form conducting films were examined using UV–vis–NIR absorption spectroscopy. The distinctive sub-band transition peaks of sodium dodecyl sulfate (SDS)-dispersed SWCNTs in water were severely suppressed in the film due to the presence of residual SDS interacting strongly with SWCNTs. The recovery of electronic structures of SWCNTs could be monitored systematically using a simple acid treatment through the peak intensities and peak positions of the corresponding transition energies of absorption spectrum. The changes in electrical and optical conductivity of SWCNT film before and after acid treatment were discussed.

Oxydianiline-pyromellitic dianhydride poly(amic acid) (ODA-PMDA PAA) was polymerized with a catalyst support of triethyl amine for controlling molecular weight. This polymer was used for electrospinning in the preparation of PAA nanofibers, a precursor of carbon nanofibers. Here the amount of catalyst and concentration of PAA solution were optimized to produce polyimide-based carbon nanofibers approximately 80 nm in diameter. The effects of molecular weight of PAA, bias voltage, and spinning rate on the morphology of electrospun PAA and polyimide nanofibers have been evaluated. We showed that the conductivity of the carbon nanofiber mat decreased with increasing nanofiber diameter, where the conductivity of polyimide-based carbon nanofiber mat was much higher than those of other types of carbon nanofiber mat. The key ingredient to increase conductivity in a carbon nanofiber mat was found to be the number of cross junctions between nanofibers.

Y-junction carbon nanocoils (Y-CNCs) were synthesized by thermal chemical vapor deposition using Ni catalyst prepared by spray-coating method. According to the emerging morphologies of Y-CNCs, several growth models were advanced to elucidate their formation mechanisms. Regarding the Y-CNCs without metal catalyst in the Y-junctions, fusing of contiguous CNCs and a tip-growth mechanism are considered to be responsible for their formation. However, as for the Y-CNCs with catalyst presence in the Y-junctions, the formation can be ascribed to nanoscale soldering/welding and bottom-growth mechanism. It is found that increasing spray-coating time for catalyst preparation generates agglomerated larger nanoparticles strongly adhering to the substrate, resulting in bottom-growth of CNCs and appearance of the metal catalyst in the Y-junctions. In the contrary case, CNCs catalyzed by isolated smaller nanoparticles develop Y-junctions with an absence of metal catalyst by virtue of weaker adhesion of catalyst with the substrate and tip-growth of CNCs.

An array of random-oriented zinc oxide nanowires (ZnO NWs) was fabricated on silicon substrate by thermal evaporation. After a thermal evaporation process, the silicon substrate was covered with a large number of uniformly distributed ZnO islands, from which non-aligned NWs with a diameter of several ten nanometres were grown. During this process, the temperature around the substrate was intentionally kept below 500 degrees C for practical consideration. From these ZnO NWs field emission was achieved. The turn-on field, under which a 10μA/cm2 current density was extracted, was measured to be 3.0V/μm. Also, the emission site distribution was investigated using the transparent anode technique. The field emission was observed to have occurred from the whole sample surface. These results suggest that ZnO NWs have great potential application in flat panel displays.

Field-ion microscopy (FIM), a tool for surface analysis with atomic resolution, has been employed to observe the end structure of single-walled carbon nanotubes (SWCNTs). FIM images revealed the existence of open SWCNT ends. Amorphous carbon atoms were also observed to occur around SWCNTs and traditional field evaporation failed to remove them. Heat treatment was found to be efficacious in altering the end structures of SWCNT bundles. Carbon and oxygen atoms released from heated tungsten filament are believed to be responsible for the decoration imposed on the SWCNT ends.

This paper firstly introduces the fiber sensor technology of conductor temperature monitoring of the dynamic compatibilization technology in transmission line. Secondly, on the basis of the principle of dynamic compatibilization technology, the fiber sensor technology of conductor temperature is applied to investigate the compatibilization technology in transmission line, and a dynamic compatibilization system is developed. At last, monitoring the carrying capacity of a certain electric transmission line throughout the day, the drawings shows the relationship between current-carrying capacity of the transmission line and the cross-sectional area of the conductor, the conductor temperature, the environment temperature, wind speed, sunshine intensity, etc. according to the experiment data. It shows that the dynamic compatibilization.

Novel hierarchical chrysanthemum-flower-like carbon nanomaterials (CFL-CNMs) were synthesized by thermal chemical vapor deposition based on acetylene decomposition. A scanning electron microscope and a transmission electron microscope were employed to observe the morphology and structure of the unconventional nanostructures. It is found that the CFL-CNMs look like a blooming chrysanthemum with a stem rather than a spherical flower. The carbon flower has an average diameter of 5 μm, an average stem diameter of 150 nm, branch diameters ranging from 20 to 70 nm, and branch lengths ranging from 0.5 to 3 μm. The morphologies of the CFL-CNMs are unlike any of those previously reported. Fishbone-like carbon nanofibers with a spindle-shaped catalyst locating at the tip can also be found. Furthermore, the catalyst split was proposed to elucidate the formation mechanism of CFL-CNMs. A large and glomerate catalyst particle at the tip of the carbon nanofiber splits into smaller catalyst particles which are catalytic-active points for branch formation, resulting in the formation of CFL-CNMs.

Graphene oxide nanosheets (GONSs) with a lateral size less than 100 nm have attracted more and more attention for their wide range of potential applications, from bionanotechnology and nanobiomedicine to surfactants. However, at present GONSs are commonly prepared from graphite nanofibers or graphite nanopowders which are both expensive. Here, a timesaving, low-cost, high-yield method is proposed for preparing ultrasmall uniform GONSs with an average lateral size of ∼30 nm, utilizing common graphite powder as the raw material in the absence of a strong acid. The obtained GONSs are able to disperse single-walled carbon nanotubes (SWCNTs) effectively, and the dispersion could withstand high-speed centrifugation. Consequently, GONSs could indeed serve as a superior surfactant for the dispersion of SWCNTs, and the dispersion could be further applied in electronics, as the GONSs may be further reduced to reduced GONSs or graphene nanosheets.

Nanodispersion of single-walled carbon nanotubes (SWCNTs) has been systematically investigated with the use of sodium dodecyl sulfate (SDS) and poly(vinylpyrrolidone) (PVP) surfactant in de-ionized water. A high concentration of nanodispersed SWCNTs up to 0.08 mg/mL was achieved with introduction of an additional dispersant of PVP by optimizing surfactant concentration, sonication time, and centrifugation speed, which was crucial to obtaining a high concentration of SWCNTs in the supernatant solution. We also demonstrate that diameters of the nanodispersed nanotubes can be sorted out by controlling the centrifugation speed and furthermore the saturated SWCNT concentration was nearly constant, independent of the initial concentration at high centrifugation speed. Two dispersion states were identified depending on the centrifugation speed: an intermediate dispersion of nanodispersion mixed with macrodispersion (I) and nanodispersion (II). This was verified by Raman spectroscopy, scanning probe microscopy, optical absorption spectroscopy, and photoluminescence measurements. The obtained SWCNT solution was stable up to about ten days. Some aggregated SWCNT solution after a long period of time was fully recovered to initial state of dispersion after re-sonication for a few minutes. Our systematic study on high concentration nanodispersion of SWCNTs with selective diameters provides an opportunity to extend the application areas of high quality SWCNTs in large quantity.

Flexible transparent conducting films (TCFs) were fabricated on a PET substrate by various methods using carbon nanotubes dispersed in organic or water-based solution. Thin multi-walled carbon nanotubes, double-walled carbon nanotubes, and single-walled carbon nanotubes were used to compare the performance for TCFs. Optimal design rules for types of nanotubes, surfactants, the degree of dispersion, and film preparation methods were discussed. The TCFs were characterized by scanning electron microscopy, TGA, Raman, optical absorption spectra, and sheet resistance. The dispersion of CNTs in water and in bisolvent has been tried. A simple acid treatment on the TCF film increased the conductivity by about four times. Doping and functionalization techniques will be further introduced to improve the conductivity of the film.