Electrochemical DNA Sensor Based on Acridine Yellow Adsorbed on Glassy Carbon Electrode

Electrochemical DNA sensors offer unique opportunities for the sensitive detection of specific DNA interactions. In this work, a voltametric DNA sensor is proposed on the base of glassy carbon electrode modified with carbon black, adsorbed acridine yellow and DNA for highly sensitive determination of doxorubicin antitumor drug. The signal recorded by cyclic voltammetry was attributed to irreversible oxidation of the dye. Its value was altered by aggregation of the hydrophobic dye molecules on the carbon black particles. DNA molecules promote disaggregation of the dye and increased the signal. This effect was partially suppressed by doxorubicin compensate for the charge of DNA in the intercalation. Sensitivity of the signal toward DNA and doxorubicin was additionally increased by treatment of the layer with dimethylformamide. In optimal conditions, the linear range of doxorubicin concentrations determined was 0.1 pM–1.0 nM, and the detection limit was 0.07 pM. No influence of sulfonamide medicines and plasma electrolytes on the doxorubicin determination was shown. The DNA sensor was tested on two medications (doxorubicin-TEVA and doxorubicin-LANS) and showed recoveries of 102–105%. The DNA sensor developed can find applications in the determination of drug residues in blood and for the pharmacokinetics studies.

A Single Step Preparation of Photothermally Active Polyvinylidene Fluoride Membranes Using Triethyl Phosphate as a Green Solvent for Distillation Applications

Membrane distillation is a growing technology that can address the growing problem of water shortage. The implementation of renewable energy and a reduction in the environmental impact of membrane production could improve the sustainability of this process. With this perspective, porous hydrophobic polyvinylidene fluoride (PVDF) membranes were prepared using triethyl phosphate (TEP) as a green solvent, using the non-solvent induced phase separation technique. Different amounts of carbon black were added to dope solutions to improve the photothermal properties of the membranes and to enable direct heating by solar energy. By optimizing the preparation conditions, membranes with porosity values as high as 87% were manufactured. Vacuum membrane distillation tests carried out using a concentrated NaCl solution at 50 °C showed distillate fluxes of up to 36 L/m² h and a complete salt rejection. Some preliminary studies on the photothermal performance were also conducted and highlighted the possibility of using such membranes in a direct solar membrane distillation configuration.

Thermal, Morphological, Electrical Properties and Touch-Sensor Application of Conductive Carbon Black-Filled Polyamide Composites

Polyamide 66 (PA66) is a well-known engineering thermoplastic polymer, primarily employed in polymer composites with fillers and additives of different nature and dimensionality (1D, 2D and 3D) used as alternatives to metals in various technological applications. In this work, carbon black (CB), a conductive nanofiller, was used to reinforce the PA66 polymer in the 9–27 wt. % CB loading range. The reason for choosing CB was intrinsically associated with its nature: a nanostructured carbon filler, whose agglomeration characteristics affect the electrical properties of the polymer composites. Crystallinity, phase composition, thermal behaviour, morphology, microstructure, and electrical conductivity, which are all properties engendered by nanofiller dispersion in the polymer, were investigated using thermal analyses (thermogravimetry and differential scanning calorimetry), microscopies (scanning electron and atomic force microscopies), and electrical conductivity measurements. Interestingly, direct current (DC) electrical measurements and conductive-AFM mapping through the samples enable visualization of the percolation paths and the ability of CB nanoparticles to form aggregates that work as conductive electrical pathways beyond the electrical percolation threshold. This finding provides the opportunities to investigate the degree of filler dispersion occurring during the transformation processes, while the results of the electrical properties also contribute to enabling the use of such conductive composites in sensor and device applications. In this regard, the results presented in this paper provide evidence that conductive carbon-filled polymer composites can work as touch sensors when they are connected with conventional low-power electronics and controlled by inexpensive and commercially available microcontrollers.

Characterization 0.1 wt.% Nanomaterial/Photopolymer Composites with Poor Nanomaterial Dispersion: Viscosity, Cure Depth and Dielectric Properties

Notably, 3D printing techniques such as digital light processing (DLP) have the potential for the cost-effective and flexible production of polymer-based piezoelectric composites. To improve their properties, conductive nanomaterials can be added to the photopolymer to increase their dielectric properties. In this study, the microstructure, viscosity, cure depth, and dielectric properties of ultraviolet (UV) light curable 0.1 wt.% nanomaterial/photopolymer composites are investigated. The composites with multi-walled carbon nanotubes (MWCNTs), graphene nanoplatelets (GNPs), and carbon black (CB) are pre-dispersed in different solvents (acetone, isopropyl alcohol, and ethanol) before adding photopolymer and continuing dispersion. For all prepared suspensions, a reduction in viscosity is observed, which is favorable for 3D printing. In contrast, the addition of 0.1 wt.% nanomaterials, even with poor dispersion, leads to curing depth reduction up to 90% compared to pristine photopolymer, where the nanomaterial dispersion is identified as a contributing factor. The formulation of MWCNTs dispersed in ethanol is found to be the most promising for increasing the dielectric properties. The post-curing of all composites leads to charge immobility, resulting in decreased relative permittivity.

Joint Effects of Carbon Black Exposure and Dietary Antioxidant Vitamin Intake on Small Airway Dysfunction

Objectives: Small airway dysfunction is considered as a precursor of chronic obstructive pulmonary disease and asthma. Our aim was to explore the joint effects of carbon black (CB) exposure and antioxidant vitamin intake on small airway dysfunction.

Methods: A total of 70 CB packers (CBPs) and 107 non-CBPs were enrolled from an established cohort of CBP. Carbon content in airway macrophage (CCAM) quantified in induced sputum was used as a bio-effective dosimetry for exposure to CB. Logistic regression models were used to examine the odds ratios (ORs) of CB and dietary intake of antioxidant vitamins on small airway dysfunction, and the dose–response association.

Results: The prevalence of small airway dysfunction was 32.9% (23 of 70) among CBPs, and 19.6% (21 of 107) among non-CBPs. For each 2.72-fold increase in CCAM, the OR of small airway dysfunction was 2.31 (95% CI = 1.20–4.44). For every 10 mg day⁻¹ increase of the vitamin C intake, the risk of small airway dysfunction decreased by 6% (OR = 0.94, 95% CI = 0.88–0.99). Compared to non-CB exposure and higher vitamin C intake, CB exposure and lower vitamin C intake (OR = 7.56, 95% CI = 1.80 to 31.81) were associated with an increased risk of small airway dysfunction.

Conclusions: Chronic exposure to a high level of CB aerosol increased the risk of small airway dysfunction in CB baggers. Dietary intake of vitamin C might be a modifiable factor for preventing small airway dysfunction.

Intracellular Cargo Delivery Induced by Irradiating Polymer Substrates with Nanosecond-Pulsed Lasers

There is a great need in the biomedical field to efficiently, and cost-effectively, deliver membrane-impermeable molecules into the cellular cytoplasm. However, the cell membrane is a selectively permeable barrier, and large molecules often cannot pass through the phospholipid bilayer. We show that nanosecond laser-activated polymer surfaces of commercial polyvinyl tape and black polystyrene Petri dishes can transiently permeabilize cells for high-throughput, diverse cargo delivery of sizes of up to 150 kDa. The polymer surfaces are biocompatible and support normal cell growth of adherent cells. We determine the optimal irradiation conditions for poration, influx of fluorescent molecules into the cell, and post-treatment viability of the cells. The simple and low-cost substrates we use have no thin-metal structures, do not require cleanroom fabrication, and provide spatial selectivity and scalability for biomedical applications.

Thermoplastic Starch-Based Composite Reinforced by Conductive Filler Networks: Physical Properties and Electrical Conductivity Changes during Cyclic Deformation

Conductive polymer composites (CPC) from renewable resources exhibit many interesting characteristics due to their biodegradability and conductivity changes under mechanical, thermal, chemical, or electrical stress. This study is focused on investigating the physical properties of electroconductive thermoplastic starch (TPS)–based composites and changes in electroconductive paths during cyclic deformation. TPS–based composites filled with various carbon black (CB) contents were prepared through melt processing. The electrical conductivity and physicochemical properties of TPS–CB composites, including mechanical properties and rheological behavior, were evaluated. With increasing CB content, the tensile strength and Young’s modulus were found to increase substantially. We found a percolation threshold for the CB loading of approximately 5.5 wt% based on the rheology and electrical conductivity. To observe the changing structure of the conductive CB paths during cyclic deformation, both the electrical conductivity and mechanical properties were recorded in parallel using online measurements. Moreover, the instant electrical conductivity measured online during mechanical deformation of the materials was taken as the parameter indirectly describing the structure of the conductive CB network. The electrical conductivity was found to increase during five runs of repeated cyclic mechanical deformations to constant deformation below strain at break, indicating good recovery of conductive paths and their new formation.

Guar Gel Binders for Silicon Nanoparticle Anodes: Relating Binder Rheology to Electrode Performance

Binding agents are a critical component of Si-based anodes for lithium-ion batteries. Herein, we introduce a composite hydrogel binder consisting of carbon black (CB) and guar, which is chemically cross-linked with glutaraldehyde as a means to reinforce the electrode structure during lithiation and improve electronic conductivity. Dynamic rheological measurements are used to monitor the cross-linking reaction and show that rheology plays a significant role in binder performance. The cross-linking reaction occurs at a faster rate and produces stronger networks in the presence of CB, as evidenced from higher gel elastic modulus in guar + CB gels than guar gels alone. Silicon nanoparticle (SiNP) electrodes that use binders with low cross-link densities (t_rxn < 2 days) demonstrate discharge capacities ∼1200 mAh g^-1 and Coulombic efficiencies >99.8% after 300 cycles at 1-C rate. Low cross-link densities likely increase the capacity of SiNP anodes because of binder-Si hydrogen-bonding interactions that accommodate volume expansions. In addition, the cross-linked binder demonstrates the potential for self-healing, as evidenced by an increased elastic modulus after the gel was mechanically fragmented, which may preserve the electrode microstructure during lithiation and increase capacity retention. The composite hydrogel with integrated conductive additives gives promise to a new type of binder for next-generation lithium-ion batteries.

Polyethylene glycol/silica and carbon black/silica xerogel composites as an adsorbent for CO2 capture

Mesoporous polyethylene glycol (PEG)/silica and carbon black (CB)/silica xerogel composites were prepared by the sol-gel method as an adsorbent for CO2 adsorption. The CO2 adsorption process was carried out under pure CO2 atmosphere at room temperature in addition to ambient air. The xerogel composites with high surface area and pore volume showed better CO2 adsorption capacity than the pure silica xerogel. After modifying samples with propylene diamine using the wet impregnation method, an increase in CO2 adsorption capacity was observed for the samples except CB/silica xerogel composite. The highest CO2 adsorption capacity was determined as approximately 0.80 mmol/g for amine modified PEG/silica xerogel composite under pure CO2 exposure. According to the adsorption-desorption cyclic stability test, it was clear that the stable samples were obtained, which is a desirable property for all CO2 adsorbents. The promising findings revealed that the xerogel composites can be efficiently used as a CO2 adsorbent instead of conventional materials in many CO2 adsorption applications. Additionally, it can be expected that the xerogel composites can provide an effective adsorption process without high-cost, complexity, corrosion, and toxicity problems.

Mechanical, Thermal, Electrical Characteristics and EMI Absorption Shielding Effectiveness of Rubber Composites Based on Ferrite and Carbon Fillers

In this work, rubber composites were fabricated by incorporation of manganese-zinc ferrite alone and in combination with carbon-based fillers into acrylonitrile-butadiene rubber. Electromagnetic parameters and electromagnetic interference (EMI) absorption shielding effectiveness of composite materials were examined in the frequency range 1 MHz-3 GHz. The influence of ferrite and fillers combination on thermal characteristics and mechanical properties of composites was investigated as well. The results revealed that ferrite imparts absorption shielding efficiency to the composites in tested frequency range. The absorption shielding effectiveness and absorption maxima of ferrite filled composites shifted to lower frequencies with increasing content of magnetic filler. The combination of carbon black and ferrite also resulted in the fabrication of efficient EMI shields. However, the EMI absorption shielding effectiveness was lower, which can be ascribed to higher electrical conductivity and higher permittivity of those materials. The highest conductivity and permittivity of composites filled with combination of carbon nanotubes and ferrite was responsible for the lowest absorption shielding effectiveness within the examined frequency range. The results also demonstrated that combination of ferrite with carbon-based fillers resulted in the enhancement of thermal conductivity and improvement of mechanical properties.

Laboratory Investigation of Carbon Black/Bio-Oil Composite Modified Asphalt

As environmentally friendly materials, carbon black and bio-oil can be used as modifiers to effectively enhance the poor high-temperature and low-temperature performance of base asphalt and its mixture. Different carbon black and bio-oil contents and shear time were selected as the test influencing factors in this work. Based on the Box-Behnken design (BBD), carbon black/bio-oil composite modified asphalt was prepared to perform the softening point, penetration, multiple stress creep and recovery (MSCR), and bending beam rheometer (BBR) tests. The response surface method (RSM) was used to analyze the test results. In addition, the base asphalt mixtures and the optimal performance carbon black/bio-oil composite modified asphalt mixtures were formed for rutting and low-temperature splitting tests. The results show that incorporating carbon black can enhance the asphalt's high-temperature performance by the test results of irrecoverable creep compliance (J_nr) and strain recovery rate (R). By contrast, the stiffness modulus (S) and creep rate (M) test results show that bio-oil can enhance the asphalt's low-temperature performance. The quadratic function models between the performance indicators of carbon black/bio-oil composite modified asphalt and the test influencing factors were established based on the RSM. The optimal performance modified asphalt mixture's carbon black and bio-oil content was 15.05% and 9.631%, and the shear time was 62.667 min. It was revealed that the high-temperature stability and low-temperature crack resistance of the carbon black/bio-oil composite modified asphalt mixture were better than that of the base asphalt mixture because of its higher dynamic stability (DS) and toughness. Therefore, carbon black/bio-oil composite modified asphalt mixture can be used as a new type of choice for road construction materials, which is in line with green development.

An Experimental Study on the Dielectric Properties of Rubber Materials

According to specific formulas, the mixing of rubber samples occurs by two methods: open mixing and internal mixing. The effects of frequency, mixing process, carbon black (CB) content, zinc oxide (ZnO) content, and stearic acid (SA) content on the dielectric properties of rubber materials were studied. The results showed that the effects of the mixing process on the dielectric properties of the rubber samples cannot be ignored, and the appropriate mixing process should be selected when preparing the required rubber materials. The dielectric constant and loss factor of the rubber samples vary depending on the frequency. The dielectric constant had a peak and valley value, while the loss factor only had a peak. The dielectric constant and loss factor of rubber samples were significantly affected by the content of CB, ZnO, and SA. The peak frequency decreased with the increase in CB content, however, the dielectric constant increased with an increase in CB content. The higher the ZnO content, the lower the peak frequency. In addition, the dielectric constant and loss factor increased with an increase in ZnO content. The higher the SA content, the greater the peak frequency. In addition, the dielectric constant and loss factor decreased with an increase in SA content. It is hoped that the experimental results obtained can provide guidance for the study of the dielectric properties, microwave absorption properties, and microwave heating characteristics of rubber polymers.

Preparation and Characterization of Eco-Friendly Spent Coffee/ENR50 Biocomposite in Comparison to Carbon Black

This study investigates the impact of spent coffee biochar (Biochar) compared to carbon black (CB) as a partial replacement for carbon black in epoxidized natural rubber (ENR). Particle size and elemental analysis were used to characterize the biochar and CB. Cure characteristics, tensile, thermal, and morphological properties on the effect of biochar and CB as filler were studied. It was found that incorporating 10 phr of spent coffee biochar could improve the composites’ tensile properties and thermal performance compared to carbon black. However, the addition of biochar significantly affects the maximum torque compared to CB and delays the vulcanization time. SEM study shows that biochar has a strong effect on the morphology of composite films. The FTIR graph reveals no substantial difference between compounds with biochar and CB. According to the thermal calorimetric study, the thermal stability of ENR-Biochar is higher than that of ENR-CB. Additionally, these findings suggest that the utilization of spent coffee as a sustainable biochar could be further explored, but little has been done in epoxidized natural rubber (ENR).

Flexible and Conductive Bioelectrodes Based on Chitosan-Carbon Black Membranes: Towards the Development of Wearable Bioelectrodes

Wearable sensors for non-invasive monitoring constitute a growing technology in many industrial fields, such as clinical or sport monitoring. However, one of the main challenges in wearable sensing is the development of bioelectrodes via the use of flexible and stretchable materials capable of maintaining conductive and biocompatible properties simultaneously. In this study, chitosan-carbon black (CH-CB) membranes have been synthesized using a straightforward and versatile strategy and characterized in terms of their composition and their electrical and mechanical properties. In this sense, CH-CB membranes showed good conductivity and mechanical resistance thanks to the presence of carbon black, which decreases the insulating behavior of chitosan, while flexibility and biocompatibility are maintained due to the dual composition of the membrane. Thus, flexible and biocompatible conductive bioelectrodes have been developed by the combined use of CH and CB without the use of toxic reagents, extra energy input, or long reaction times. The membranes were modified using the enzymes Glucose Oxidase and Laccase in order to develop flexible and biocompatible bioelectrodes for enzymatic glucose biofuel cells (BFCs) and glucose detection. A BFC assembled using the flexible bioelectrodes developed was able to deliver 15 µW cm^-2, using just 1 mM glucose as biofuel, and up to 21.3 µW·cm^-2 with higher glucose concentration. Additionally, the suitability of the CH-CB membranes to be used as a glucose sensor in a linear range from 100 to 600 µM with a limit of detection (LOD) of 76 µM has been proven. Such demonstrations for energy harvesting and sensing capabilities of the developed membrane pave the way for their use in wearable sensing and energy harvesting technologies in the clinical field due to their good mechanical, electrical, and biocompatible properties.

Small Airway Wall Thickening Assessed by Computerized Tomography Is Associated With Low Lung Function in Chinese Carbon Black Packers

Nanoscale carbon black as virtually pure elemental carbon can deposit deep in the lungs and cause pulmonary injury. Airway remodeling assessed using computed tomography (CT) correlates well with spirometry in patients with obstructive lung diseases. Structural airway changes caused by carbon black exposure remain unknown. Wall and lumen areas of sixth and ninth generations of airways in 4 lobes were quantified using end-inhalation CT scans in 58 current carbon black packers (CBPs) and 95 non-CBPs. Carbon content in airway macrophage (CCAM) in sputum was quantified to assess the dose-response. Environmental monitoring and CCAM showed a much higher level of elemental carbon exposure in CBPs, which was associated with higher wall area and lower lumen area with no change in total airway area for either airway generation. This suggested small airway wall thickening is a major feature of airway remodeling in CBPs. When compared with wall or lumen areas, wall area percent (WA%) was not affected by subject characteristics or lobar location and had greater measurement reproducibility. The effect of carbon black exposure status on WA% did not differ by lobes. CCAM was associated with WA% in a dose-dependent manner. CBPs had lower FEV1 (forced expiratory volume in 1 s) than non-CBPs and mediation analysis identified that a large portion (41-72%) of the FEV1 reduction associated with carbon black exposure could be explained by WA%. Small airway wall thickening as a major imaging change detected by CT may underlie the pathology of lung function impairment caused by carbon black exposure.

Self-Sensing Properties of Fly Ash Geopolymer Doped with Carbon Black under Compression

The development of smart materials is a basic prerequisite for the development of new technologies enabling the continuous non-destructive diagnostic analysis of building structures. Within this framework, the piezoresistive behavior of fly ash geopolymer with added carbon black under compression was studied. Prepared cubic specimens were doped with 0.5, 1 and 2% carbon black and embedded with four copper electrodes. In order to obtain a complex characterization during compressive loading, the electrical resistivity, longitudinal strain and acoustic emission were recorded. The samples were tested in two modes: repeated loading under low compressive forces and continuous loading until failure. The results revealed piezoresistivity for all tested mixtures, but the best self-sensing properties were achieved with 0.5% of carbon black admixture. The complex analysis also showed that fly ash geopolymer undergoes permanent deformations and the addition of carbon black changes its character from quasi-brittle to rather ductile. The combination of electrical and acoustic methods enables the monitoring of materials far beyond the working range of a strain gauge.

[Roles of ERK/JNK in carbon black induced AP-1 cell signaling pathway changes]

OBJECTIVE

To investigate the role of ERK/JNK in the alteration of activator protein-1(AP-1) signaling pathway in human embryonic lung fibroblasts(HELFs) induced by carbon black.

METHODS

HELFs were cultured in RPMI 1640 medium containing 0, 15, 30, 60, 120 or 240 μg/mL carbon black for 24 h, and the appropriate dose of carbon black was determined by MTT assay result. HELFs were divided into three groups: HELFs, HELFs transfected with ERK dominant negative mutant plasmid(DN-ERK) and HELFs transfected with JNK dominant negative mutant plasmid(DN-JNK). 100 μg/mL carbon black was used to treat HELFs(CB), DN-ERK HELFs(CB-DN-ERK), DN-JNK HELFs(CB-DN-JNK), and HELFs without any treatment were considered as control group. At 0, 1, 2, 4, 8, 12, 24 and 36 h of CB and control groups HELFs, the western blot was used to detect ERK, p-ERK, JNK, p-JNK, p38, p-p38, c-Jun, p-c-Jun, c-Fos, p-c-Fos protein expression levels, and AP-1 activity was detected by luciferase method. Whereas CB-DN-ERK and CB-DN-JNK HELFs were detected only at 24 h.

RESULTS

Compared with the protein expression levels at 0 h, CB group HELFs ERK and p-ERK protein expression increased at each time point, whereas p38 protein expression decreased. AP-1 activity of CB group HELFs was declined to the lowest at 8 h(0.72±0.12), and upregulated to the peak at 36 h(1.38±0.11). CB group HELFs c-Fos, p-c-Fos and c-Jun protein expression levels at each time point from 1 h to 24 h were greater than those of 0 h, and p-c-Jun protein expression levels at 1 h, 2 h, 4 h, 8 h, 36 h were also greater than those of 0 h. CB group HELFs AP-1 activity, ERK, p-ERK, JNK, p-JNK, p38, p-p38, c-Jun, p-c-Jun, c-Fos, p-c-Fos protein expression levels changes followed biphasic patterns. There were no statistically significant differences in AP-1 activity between CB group HELFs(1.03±0.10) and CB-DN-ERK group(1.02±0.04) or CB-DN-JNK group(1.09±0.10) HELFs(t=0.16, P=0.88; t=0.73, P=0.50). However, compared with CB group HELFs, c-Fos(t=5.31, P=0.01), p-c-Fos(t=4.33, P=0.01), p-c-Jun(t=10.95, P& lt; 0.01)in CB-DN-JNK group, and c-Fos protein expression levels in CB-DN-ERK group(t=42.72, P& lt; 0.01)were significantly decreased.

CONCLUSION

While carbon black induces HELFs increased protein expression levels of ERK, p-ERK, c-Jun, p-c-Jun, c-Fos and p-c-Fos, JNK may upregulate c-Fos, p-c-Fos, p-c-Jun protein expression levels, and ERK may upregulate c-Fos protein expression level.

Effect of Secondary Carbon Nanofillers on the Electrical, Thermal, and Mechanical Properties of Conductive Hybrid Composites Based on Epoxy Resin and Graphite

In this work, we present a comparative study of the impact of secondary carbon nanofillers on the electrical and thermal conductivity, thermal stability, and mechanical properties of hybrid conductive polymer composites (CPC) based on high loadings of synthetic graphite and epoxy resin. Two different carbon nanofillers were chosen for the investigation—low-cost multi-layered graphene nanoplatelets (GN) and carbon black (CB), which were aimed at improving the overall performance of composites. The samples were obtained by a simple, inexpensive, and effective compression molding technique, and were investigated by the means of, i.a., scanning electron microscopy, Raman spectroscopy, electrical conductivity measurements, laser flash analysis, and thermogravimetry. The tests performed revealed that, due to the exceptional electronic transport properties of GN, its relatively low specific surface area, good aspect ratio, and nanometric sizes of particles, a notable improvement in the overall characteristics of the composites (best results for 4 wt % of GN; σ = 266.7 S cm⁻¹; λ = 40.6 W mK⁻¹; fl. strength = 40.1 MPa). In turn, the addition of CB resulted in a limited improvement in mechanical properties, and a deterioration in electrical and thermal properties, mainly due to the too high specific surface area of this nanofiller. The results obtained were compared with US Department of Energy recommendations regarding properties of materials for bipolar plates in fuel cells. As shown, the materials developed significantly exceed the recommended values of the majority of the most important parameters, indicating high potential application of the composites obtained.

Silicone Rubber Composites Reinforced by Carbon Nanofillers and Their Hybrids for Various Applications: A Review

Without fillers, rubber types such as silicone rubber exhibit poor mechanical, thermal, and electrical properties. Carbon black (CB) is traditionally used as a filler in the rubber matrix to improve its properties, but a high content (nearly 60 per hundred parts of rubber (phr)) is required. However, this high content of CB often alters the viscoelastic properties of the rubber composite. Thus, nowadays, nanofillers such as graphene (GE) and carbon nanotubes (CNTs) are used, which provide significant improvements to the properties of composites at as low as 2–3 phr. Nanofillers are classified as those fillers consisting of at least one dimension below 100 nanometers (nm). In the present review paper, nanofillers based on carbon nanomaterials such as GE, CNT, and CB are explored in terms of how they improve the properties of rubber composites. These nanofillers can significantly improve the properties of silicone rubber (SR) nanocomposites and have been useful for a wide range of applications, such as strain sensing. Therefore, carbon-nanofiller-reinforced SRs are reviewed here, along with advancements in this research area. The microstructures, defect densities, and crystal structures of different carbon nanofillers for SR nanocomposites are characterized, and their processing and dispersion are described. The dispersion of the rubber composites was reported through atomic force microscopy (AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The effect of these nanofillers on the mechanical (compressive modulus, tensile strength, fracture strain, Young’s modulus, glass transition), thermal (thermal conductivity), and electrical properties (electrical conductivity) of SR nanocomposites is also discussed. Finally, the application of the improved SR nanocomposites as strain sensors according to their filler structure and concentration is discussed. This detailed review clearly shows the dependency of SR nanocomposite properties on the characteristics of the carbon nanofillers.

Modification of Carbon Black with Hydrogen Peroxide for High Performance Anode Catalyst of Direct Methanol Fuel Cells

In this study, high-surface-area carbon black is used to support PtRu. In order to increase the functional groups on the surface of carbon black and to have a more homogenous dispersed PtRu metal, the surface of carbon black is functionalized by H₂O₂. PtRu/carbon black is synthesized by the deposition–precipitation method. NaH₂PO₂ is used as the reducing agent in preparation. These catalysts are characterized by N₂ sorption, temperature-programmed desorption, X-ray diffraction, transmission electron microscope, and X-ray photoelectron spectroscopy. The methanol oxidation ability of the catalyst is tested by cyclic voltammetry measurement. Using H₂O₂ to modify carbon black can increase the amount of functional groups on the surface, thereby increasing the metal dispersion and decreasing metal particle size. NaH₂PO₂ as a reducing agent can suppress the growth of metal particles. The best modified carbon black catalyst is the one modified with 30% H₂O₂. The methanol oxidation activity of the catalyst is mainly related to the particle size of PtRu metal, instead of the surface area and conductivity of carbon black. The PtRu catalyst supported by this modified carbon black has very high activity, with an activity reaching 309.5 A/g.

ROCK inhibitor attenuates carbon blacks-induced pulmonary fibrosis in mice via Rho/ROCK/NF-kappa B pathway

Exposure to carbon blacks (CBs) has been associated with the progression of pulmonary fibrosis, whereas the mechanism is still not clear. We therefore aimed to investigate the effect of RhoA/ROCK pathway on pulmonary fibrosis caused by CBs exposure. Western blot analysis indicated that CBs could promote the activation of RhoA/ROCK pathway and phosphorylation of p65 and IκBα in mice lung. However, ROCK inhibitor Y-27632 could attenuate phosphorylation levels of p65 and IκBα and restore histopathological changes of the lung tissue. Then, we evaluated the effect of RhoA/ROCK pathway on pulmonary fibrosis by detecting the expression levels of α-SMA, vimentin, and Collagen type-I (Col-I), which could be partly inhibited by Y-27632. It was assumed that inhibition of ROCK could be a promising therapeutic candidate for CBs-induced pulmonary fibrosis, which possibly through the blockage of RhoA/ROCK/NF-κB pathway.

Hollow Silica Particles: A Novel Strategy for Cost Reduction

Thermal insulation materials are highly sought after for applications such as building envelopes, refrigerators, cryogenic fuel storage chambers, and water supply piping. However, current insulation materials either do not provide sufficient insulation or are costly. A new class of insulation materials, hollow silica particles, has attracted tremendous attention due to its potential to provide a very high degree of thermal insulation. However, current synthesis strategies provide hollow silica particles at very low yields and at high cost, thus, making the particles unsuitable for real-world applications. In the present work, a synthesis process that produces hollow silica particles at very high yields and at a lower cost is presented. The effect of an infrared heat absorber, carbon black, on the thermal conductivity of hollow silica particles is also investigated and it is inferred that a carbon black-hollow silica particle mixture can be a better insulating material than hollow silica particles alone.

A Facile Method to Realize Oxygen Reduction at the Hydrogen Evolution Cathode of an Electrolytic Cell for Energy-Efficient Electrooxidation

Electrochemical oxidation, widely used in green production and pollution abatement, is often accompanied by the hydrogen evolution reaction (HER), which results in a high consumption of electricity and is a potential explosion hazard. To solve this problem, we report here a method for converting the original HER cathode into one that enables the oxygen reduction reaction (ORR) without having to build new electrolysis cells or be concerned about electrolyte leakage from the O₂ gas electrode. The viability of this method is demonstrated using the electrolytic production of ammonium persulfate (APS) as an example. The original carbon black electrode for the HER is converted to an ORR electrode by first undergoing in situ anodization and then contacting O₂ or air bubbled from the bottom of the electrode. With this sole change, APS production can achieve an electric energy saving of up to 20.3%. Considering the ease and low cost of this modification, such significant electricity savings make this method very promising in the upgrade of electrochemical oxidation processes, with wide potential applications.

Structure-Function Relationships of Nanocarbon/Polymer Composites for Chemiresistive Sensing: A Review

Composites of organic compounds and inorganic nanomaterials provide novel sensing platforms for high-performance sensor applications. The combination of the attractive functionalities of nanomaterials with polymers as an organic matrix offers promising materials with tunable electrical, mechanical, and chemisensitive properties. This review mainly focuses on nanocarbon/polymer composites as chemiresistors. We first describe the structure and properties of carbon nanofillers as reinforcement agents used in the manufacture of polymer composites and the sensing mechanism of developed nanocomposites as chemiresistors. Then, the design and synthesizing methods of polymer composites based on carbon nanofillers are discussed. The electrical conductivity, mechanical properties, and the applications of different nanocarbon/polymer composites for the detection of different analytes are reviewed. Lastly, challenges and the future vision for applications of such nanocomposites are described.

Compressive Fatigue Behavior of Gum and Filled SBR Vulcanizates

The influence of carbon black on physical mechanical properties, compressive fatigue life, and the temperature changes during compression fatigue process of styrene-butadiene rubber (SBR) vulcanizates were explored. A series of unfilled and filled SBR compounds were prepared, and the compressive fatigue behaviors of the vulcanizates were performed on a mechanical testing and simulation (MTS) machine. The top surfaces of the filled SBR were imaged using scanning electron microscopy (SEM) after 105 cycles of compressive fatigue. The filled SBR shows greater compressive fatigue resistance than the unfilled SBR. The incorporation of carbon black into SBR improves the creep resistance. The best compressive fatigue resistance for the filled SBR was achieved by the addition of 30 phr carbon black. With the increase of carbon black content, the energy dissipation and the heat build-up increase simultaneously. Furthermore, SEM images of the vulcanizates suggest that the crack propagation mechanism of the unfilled and the filled SBR was different. For the unfilled SBR, due to periodical compressive stress, the polymer chains can be destroyed, and the cracks can be easily initiated and propagated, showing serious damage on the top surfaces of the specimen. However, for the filled SBR, the carbon black agglomeration around the cracks can greatly delay the generation of the cracks, decrease the fatigue damage, and ultimately improve the fatigue resistance.