Carbon Black Loading Research Articles

Dual functionality of cathode microporous layers: Reducing hydrogen permeation and enhancing performance in proton exchange membrane water electrolyzers

Hydrogen permeation and cell performance are critical factors for the safe and efficient operation of proton exchange membrane (PEM) water electrolysis. In this study, the effects of a cathode microporous layer (MPL) on water transport, hydrogen permeation, and cell performance in a proton exchange membrane water electrolyzer (PEMWE) were investigated. Results reveal that adding an MPL between the catalyst layer (CL) and the porous transport layer (PTL) at the cathode reduces interfacial contact resistance by approximately 60 % under 400 N cm−2, leading to superior performance. The wettability of the MPL plays a crucial role in water transport and hydrogen permeation in PEMWEs. The hydrophobic MPL-P-CB4, which uses polytetrafluoroethylene (PTFE) as a binder with a carbon black (CB) loading of 4 mgCB cm−2, enhances the crossover of water and hydrogen from the cathode to the anode through back diffusion, exceeding the technical safety criterion of 2 vol% H2 in the anode product gas (50 % lower explosion limit) at 2.0 A cm−2. However, the hydrophilic MPL with Nafion ionomers as binders (MPL-N-CB4) facilitates efficient removal of water and hydrogen from the cathode CL to the cathode flow field via capillary pressure, resulting in only 0.2 vol% H2 in O2 at 2.0 A cm−2. Consequently, a hydrophilic MPL is optimal for achieving superior performance and low-hydrogen-crossover in a PEMWE cathode. This study provides valuable insights for designing the PTL/CL interface in next-generation PEMWE cathodes.

Optimised graphite/carbon black loading of recycled PLA for the production of low-cost conductive filament and its application to the detection of β-estradiol in environmental samples

The production, optimisation, physicochemical, and electroanalytical characterisation of a low-cost electrically conductive additive manufacturing filament made with recycled poly(lactic acid) (rPLA), castor oil, carbon black, and graphite (CB-G/PLA) is reported. Through optimising the carbon black and graphite loading, the best ratio for conductivity, low material cost, and printability was found to be 60% carbon black to 40% graphite. The maximum composition within the rPLA with 10 wt% castor oil was found to be an overall nanocarbon loading of 35 wt% which produced a price of less than £0.01 per electrode whilst still offering excellent low-temperature flexibility and reproducible printing. The additive manufactured electrodes produced from this filament offered excellent electrochemical performance, with a heterogeneous electron (charge) transfer rate constant, k0 calculated to be (2.6 ± 0.1) × 10−3 cm s−1 compared to (0.46 ± 0.03) × 10−3 cm s−1 for the commercial PLA benchmark. The additive manufactured electrodes were applied to the determination of β-estradiol, achieving a sensitivity of 400 nA µM−1, a limit of quantification of 70 nM, and a limit of detection of 21 nM, which compared excellently to other reports in the literature. The system was then applied to the detection of ß-estradiol within four real water samples, including tap, bottled, river, and lake water, where recoveries between 95 and 109% were obtained. Due to the ability to create high-performance filament at a low material cost (£0.06 per gram) and through the use of more sustainable materials such as recycled polymers, bio-based plasticisers, and naturally occurring graphite, additive manufacturing will have a permanent place within the electroanalysis arsenal in the future.Graphical abstract

Structure-performance relationship of polypropylene/elastomer/carbon black composites as high voltage cable shielding layer

As polypropylene (PP) is a competitive insulating material for next generation high-voltage cable, the corresponding PP based cable semi-conductive shielding layer material needs to be developed. This paper developed an excellent material prescription and proposed an analytical method of structure-performance relationship for the application and the evaluation of PP-based cable shielding layer. First, PP/POE/CB and PP/SEBS/CB composites with different carbon black (CB) loading were prepared and their electrical and mechanical properties were compared. Through thermal analysis technique, crystalline property and thermal stability of the composites were studied in detail. And the synchrotron radiation X-ray scattering techniques were employed to analyze the distribution of carbon black in the blend semi-quantitatively. The analysis result turns out the enrichment of carbon black in POE phase and its instability at high temperature limits its application under cable operation conditions. In contrast, PP/SEBS/CB30phr is recommended for lower thermal deformation, lower PTC effect and better mechanical parameters.

Effect of Carbon Black Type and Loading on Properties of Natural Rubber/Butadiene Rubber Blends for Solid Tire Tread Compounds

Effect of Carbon Black Type and Loading on Properties of Natural Rubber/Butadiene Rubber Blends for Solid Tire Tread Compounds

Study on the mechanism of constructing structure defects on surface of activated carbon with carbon black to promote hydrogen production by thermal-decomposition of methane

Hydrogen production from catalytic decomposition of methane is a promising method of hydrogen production that caters to low-carbon energy sources. The low cost and easy regeneration of carbon-based catalysts is more compatible with the concept of sustainability than metal catalysts. The key problem with catalytic decomposition using activated carbon is the rapid deactivation of the activated carbon due to structural changes caused by the production and accumulation of deposited carbon. Carbon black, on the other hand, exhibits slowly increasing catalytic performance in the catalytic decomposition of methane. Therefore, combining the properties of the two, it is proposed to disperse and load the nano conductive carbon black onto the surface of urea-modified activated carbon, so that the activated carbon can also have self-repairing ability at a later stage. It is shown that the combined application of carbon black loading and urea modification enhances the structural properties of the activated carbon by enriching the microporous structure of the activated carbon surface, increasing the disorder of its crystal structure, and altering the content and concentration of oxygen-containing functional groups on the surface. These microstructural changes combined to enhance the overall catalytic activity of the activated carbon, including its late deactivation time and catalytic performance after deactivation.

Characterisation of Novel and High Performing Double-Sided Microporous-Layers-Coated Gas Diffusion Layers for Polymer Electrolyte Membrane Fuel Cells

This study aims to experimentally evaluate the impact of a double-sided microporous layer coating on gas diffusion layers in terms of their key properties and fuel cell performance, in comparison to conventional single-sided coated gas diffusion layers (GDLs). Vulcan black and Ketjenblack were used as the carbon black materials. This was to investigate the sensitivity of the results with respect to the type of carbon black used. The results showed that the in-plane electrical conductivity is almost insensitive to microporous layer (MPL) loading and carbon black type. Furthermore, the electrical conductivity of all the MPL-coated GDLs are slightly lower than that of the uncoated GDL. The Ketjenblack black MPL samples were found to demonstrate higher gas permeability than the Vulcan black samples. The addition of the MPL resulted in a favourable shift in pore size distribution, with prominent micropores observed in both single- and double-sided MPL-coated GDLs. Contact angle measurements indicated a slight increase in the hydrophobicity with the addition of a microporous layer, but without significant differences between carbon black types or loading levels. Cross-sectional SEM images showed that there was a higher level of MPL penetration into the carbon substrate for the GDLs coated with Vulcan black as compared to a Ketjenblack coating. In situ fuel cell testing demonstrated the superior performance of the double-sided Vulcan black MPL-coated GDL under high humidity conditions, while the single-sided Vulcan black MPL-coated GDL exhibited better performance at low humidity conditions. All the above findings have been thoroughly discussed and justified.

The Numerical and Experimental Investigation of Piezoresistive Performance of Carbon Nanotube/Carbon Black/Polyvinylidene Fluoride Composite.

The composites with multiple types of nano-carbon fillers have better electrical conductivity and piezoresistive properties as compared with composites with a single type of nano-carbon fillers. As previously reported, the nano-carbon fillers with various aspect ratios, such as carbon nanotube (CNT) and carbon black (CB), have synergistic enhanced effects on the piezoresistive performance of composite sensors. However, most of the works that have been reported are experimental investigations. The efficient and usable numerical simulation investigation needs to be further developed. In this study, based on an integrated 3D statistical resistor network model, a numerical simulation model was created to calculate the piezoresistive behavior of the CNT/CB/ Polyvinylidene Fluoride (PVDF) composite. This model also takes into account the tunneling effect between nearby nano-fillers. It is found from numerical simulation results that the piezoresistive sensitivity of composite simulation cells can be influenced by the fraction of CNT and CB. In the case that the CNT content is 0.073 wt.%, the best force-electrical piezoresistive sensitivity can be achieved when the CB loading is up to 0.2 wt.%. To verify the validity of the simulation model, the previous experimental investigation results are also compared. The experimental results confirm the validity of the model. The investigation is valuable and can be utilized to design a strain sensor for this nano-composite with increased sensitivity.

Effect of carbon black components on rolling mechanical properties of tread rubber material by using improved digital image correlation

AbstractThe rolling and sliding state of the tread rubber material within contact patch was very important to the handling stability and safety of the vehicle. In this paper, first, the absolute coordinate system was introduced into the digital image correlation method, which improved the ability of the traditional digital image correlation method to solve the large deformation of polymer material surface. Second, a new calculation method of rolling friction coefficient based on the brush model was proposed. Third, a non‐contact full‐field rolling dynamics experimental device was developed to study the effects of carbon black components, rotational speed and vertical load on the rolling mechanical characteristics of tread rubber material. On this basis, the rolling mechanical characteristics of tread rubber material with different formulations were obtained by analyzing the distribution properties of global strain rate, full‐field longitudinal speed and full‐field longitudinal acceleration and the variation laws of transverse/longitudinal strain rate, trajectory of marked points, stress‐strain hysteresis curve and rolling friction coefficient. Finally, the influence mechanism of carbon black composition on rolling mechanical properties of tread rubber material was revealed.

Fabrication of styrene–butadienestyrene (SBS) matrix-based flexible strain sensors with brittle cellulose nanocrystal (CNC)/carbon black (CB) segregated networks

Strain sensors based on conductive polymer composites (CPCs) filled with carbon black (CB) are potential as wearable detection devices for mass production due to their low cost. However, it is still challenging to design sensors with low CB loading and the conductivity and sensitivity guaranteed. Herein, a Pickering emulsion template method was conducted to design the styrene–butadienestyrene (SBS) matrix-based strain sensors, in which a conducting structure of segregated cellulose nanocrystal (CNC)/carbon black (CB) networks was constructed, improving the conductivity and reducing the percolation threshold (φc) to ∼0.28 wt%. Besides, the CNC incorporation and defect construction in the networks greatly promote the sensitivity of the sensor, the maximum gauge factor (GF) determined is beyond 260 within the 200% strain. Moreover, the sensor can exhibit remarkable working durability and reproductivity. All these above favorable properties have empowered the strain sensor with superior applicability in detecting various human motions (finger bending, elbow bending, knee bending, neck rotation, cheek bulging, and swallowing).

Nonmonotonic Variation of Rutting Resistance and Fatigue Life for Polyethylene Modified Bitumen with Different Carbon Black Loading

Polyethylene (PE) and carbon black (CB) were premixed in this study for bitumen modification. The service performance of PE/CB-modified bitumen (PMB) was mainly explored by multiple stress creep recovery (MSCR) and linear amplitude sweep (LAS) tests to reveal the rutting resistance and fatigue life, respectively. Low-temperature properties were evaluated by glass transition temperature (Tg) measured by dynamic mechanical analysis (DMA). X-ray diffraction (XRD) results suggested that the crystalline structure of PE was almost the same regardless of different CB loading additions. It was found that the both rutting resistance and fatigue life of PMBs showed nonmonotonic variation with CB loading. The mechanism for this variation was closely related to the microstructure induced by phase separation, CB nanoparticle aggregation and PE crystallinity. As revealed by optical and atomic force microscopy, two different phase structures, network and droplet-matrix structure, can be formed in PMBs when the CB loading changes. In particular, a double percolated network structure can be formed, consisting of a PE-rich network in the bitumen-matrix and CB nanoparticle network within a PE-rich phase. With the presence of this structure, the rutting resistance and fatigue life of PMB can be significantly improved.

Steady State and Dynamic Oscillatory Shear Properties of Carbon Black Filled Elastomers

A correlation between the steady shear viscosity and complex dynamic viscosity of carbon black (CB) filled rubbers was found by evaluating the Cox-Merz rule and an alternative approach originally proposed by Philippoff for dilute polymer solutions, but since applied to amorphous polymers and concentrated suspensions. This was done by measuring the rheological properties of 16 industrially important rubber mixes containing CB N660 at concentrations of 20 and 35% by volume. A capillary rheometer at various shear rates and a dynamic oscillatory shear rheometer at small and large amplitude oscillatory shear (SAOS and LAOS) were used. The apparent viscosity, storage and loss moduli, complex dynamic viscosity and Fourier transform harmonics were measured. Generally, the shear stress, storage and loss moduli increased with increasing CB loading. Also, the ratio of third and fifth stress harmonics to first harmonics increased with increasing strain amplitude and filler loading. Viscous Lissajous figures (shear stress versus shear rate) at a strain amplitude of 14% showed a nearly linear response for compounds containing CB at 20% by volume. All other shear stress responses demonstrated a strong nonlinearity. The stress waveforms at a strain amplitude of 140% for compounds containing 35% CB by volume displayed a backwards tilted shape expected for highly filled compounds. The stress waveforms at a strain amplitude of 1,000% tended toward a rectangular shape expected for pure polymer. Generally, the nonlinear response of the compounds appeared to be dominated by the filler at strain amplitudes of 14% and 140% and by the rubber matrix at a strain amplitude of 1,000%. The Cox-Merz rule was not applicable for any of the compounds with their complex dynamic viscosity being greater than the apparent viscosity. However, a modification of the approach proposed by Philippoff provided reasonable agreement between the apparent viscosity and complex dynamic viscosity.

The effect of nanoparticle fillers on glass fiber/poly‐ether‐ether‐ketone prepreg laser absorbance, thermal conductivity and interlayer performance

AbstractAiming at the use of glass fiber reinforced poly‐ether‐ether‐ketone (GF/PEEK) with low laser absorbance in laser assisted tape winding/placement (LATW/LATP), a method for dyeing GF/PEEK prepreg with nanoparticle fillers (NFs) is presented. First, the effects of carbon black (CB) and graphite (G) NFs on composites laser absorbance and reflection pattern were quantified, and the complex refractive index model was derived. Next, the effects of NFs on composites transverse thermal conductivity were tested, and the accuracy of four thermal conductivity prediction models were compared. Finally, the effects of NFs on composites interlayer performance were studied. The optical test results showed that NFs could improve laser absorbance while not changing reflection pattern, and the increase rate of absorbance for CB was higher than for G. As calculated by complex refractive index model, GF/PEEK with 1‐layer thickness could achieve complete laser absorption by addition of either 2.74%CB or 3.78%G. The thermal conductivity test results showed that NFs could improve composites transverse thermal conductivity. The increase rate of thermal conductivity for G was higher than for CB. Among the four prediction model, the Lewis‐Nielsen model had correct prediction regularity and was within 10% predict deviation. Based on this model, the transverse thermal conductivity of GF/PEEK/2.74%CB was 0.557 W/m K, and of GF/PEEK/3.78%G was 0.592 W/m K. The mechanical test results showed that the CB loading ≤4% had little effect on interlayer performance, while the G decreased interlayer performance. Consequently, adding CB at a low loading is a better way to realize GF/PEEK application in LATW/LATP.

Preferential localization of conductive filler in ethylene‐co‐methyl acrylate/thermoplastic polyolefin polymer blends to reduce percolation threshold and enhanced electromagnetic radiation shielding over K band region

AbstractTo minimize radiation pollution at ultra‐low filler concentrations, there is a growing interest in microwave‐absorbing materials based on polymer blends composites. Herein, ethylene‐co‐methyl acrylate (EMA)/thermoplastic polyolefin (TPO) blend composites were prepared by employing solution mixing utilizing conductive Vulcan XC 72 carbon black (VCB) as nanofiller. The work focused on the reduction of electrical percolation and outstanding electromagnetic interference (EMI) shielding performance in low loading caused by the preferential distribution of carbon particles in one phase (ethylene‐co‐methyl acrylate copolymer) of the co‐continuous immiscible polymer blend. The fabricated conductive blend was further tested to ensure its superiority in physic‐mechanical and thermal stability. The morphology analysis reveals that the VCB particles are selectively localized in EMA phase of the blend which facilitates the formation of compact spatial conductive network throughout the matrix for electronic hopping. High electrical conductivity is achieved in the scale 10−2 S/cm for the prepared composites with 30 wt% of carbon black loading whereas a total EMI shielding effectiveness of −29 dB and thermal conductivity of ~0.75 W/m·K are achieved for this same filler content. This study reveals that the fabricated conductive polymer nanocomposites can be effectively utilized as promising EMI shields in the future generation of stretchable and wearable electronics.

Electromechanical Properties and Resistance Signal Fatigue of Piezoresistive Fiber-Based Strain Gauges

Piezoresistive nanocomposite fibers are essential elements for smart wearables and have recently become a research hotspot because of their high sensitivities at large deformations in the plastic regime. However, little attention has been paid to the electromechanical properties of such fibers at low strains where the resistance–strain (R–ε) relationship is reliably linear. In addition, prediction of the resistance signal stability for these materials during cyclic loading remains unreported. Here, we studied these two aspects using wet-spun piezoresistive nanocomposite fibers from polyether block amide (PEBA) composed of a hybrid conductive filler network of carbon black (CB) and carbon nanotubes (CNTs) in which the CB loading in the PEBA matrix was varied at a constant volume fraction of CNTs. We found the R–ε linear relationship (working factor, W) to increase with CB filler loading from 0.01 to 0.058. In addition, the gauge factors of these fibers varied inversely with W from 16.89 to 3.81. Using fatigue theory, we predicted the endurance limit of PEBA/CB-CNT fibers in the elastic regime to be ∼34.9 cycles. Although our fibers were extremely deformable, up to 500% strain, as is the case for most piezoresistive nanocomposite fibers, this work reveals the working range to be actually very small, comparable to rigid conventional strain gauges. We believe with PEBA/CB-CNT fibers’ robust mechanical properties and the ease with which the electromechanical signal can be quantified with the fatigue model, they would be ideal materials to be integrated into textiles to perform as tough, finely tuned strain sensors for a range of rigorous bodily monitoring such as low-strain impacts and joint movements.

Comparison of Carbon-Nanoparticle-Filled Poly(Butylene Succinate-co-Adipate) Nanocomposites for Electromagnetic Applications.

Electrostatic dissipative (ESD), anti-static (AS), and electromagnetic interference (EMI) shielding materials are commonly based on commodity fossil-fuel-based plastics. This, in turn, contributes to ever-growing non-biodegradable plastic pollution. Graphene nanoplatelets (GN), multi-walled carbon nanotubes (MWCNT), nanostructured carbon black (NCB), and amorphous carbon black (CB) were utilized as nanofillers to prepare bio-based and biodegradable poly(butylene succinate-co-adipate) (PBSA) nanocomposites. Solvent-cast composites were prepared with 1.1 to 30.0 vol.% nanoparticle loading. The literature mainly focuses on relatively low loadings; therefore, for this research, filler loadings were increased up to 30 vol.% but the maximum loading for NCB and CB loadings only reached 17.4 vol.% due to a lack of dimensional stability at higher loadings. The composites were characterized using tensile testing, volumetric and surface conductivity measurements, thermal conductivity measurements, dielectric spectroscopy in the microwave region, and transmittance in the terahertz range. Tensile tests showed excellent carbon filler compatibility and enhanced tensile strength for loadings up to 5 vol.% (up to 20 vol.% for MWCNT). The highest thermal conductivity values were reached for the MWCNT filler, with the 30.0 vol.% filled composite reaching 0.756 W/mK (262% increase over PBSA). All fillers were able to produce composites that yielded volume conductivities above 10−10 S/m. Composites with MWCNT, GN, and NCB inclusions above the percolation threshold are suitable for EMI applications in the microwave and THz frequency range.

Upscale recycling of nonwoven polypropylene waste using a novel blending method

AbstractWaste management of the nonwoven polypropylene (PP) fabric has become an emerging issue due to its increased usage. This study presents the upscale recycling of PP nonwoven fabric scrap generated during medical‐grade disposable gown manufacturing. To prepare PP and carbon black (CB) nanocomposite, a two‐step novel melt blending process is used. A maximum density of 937 kg/m3, shore D hardness of 74.45, and highest improvement in UV degradation resistance with a carbonyl index of 0.40 is recorded at 2 wt% of the CB while melt flow index is the lowest at 0.5 wt% of the CB. The results of this study revealed the peak melting point (161.81°C), thermal degradation temperature (421°C), highest flexural strength (49.16 MPa), and Izod impact strength (6.76 kJ/m2) are at 0.50 wt% of CB loading. A morphological study indicated that the highest agglomeration of CB particles was found at 2 wt% CB. The results showed that the optimum value of CB in PP nanocomposite is 0.5 wt%, at which the majority of the properties are maximized. This research might pave the way for the recycling of nonwoven PP waste fabric and provide an alternative to the exciting virgin raw materials.

Free volume in carbon‐black‐filled isoprene rubber investigated by positron annihilation lifetime spectroscopy

AbstractThe free volume in the amorphous phase of a simple carbon‐black‐filled peroxide cross‐linked isoprene rubber (IR) is investigated by positron annihilation lifetime spectroscopy to clarify the structural changes in the rubber phase by the carbon black (CB) fillers. The ortho‐positronium (o‐Ps) pick‐off annihilation lifetime measured in the rubber without CB is around 2.8 ns and is found to be almost constant even after CB filling. This result indicates that in a portion of the rubber phase the free volume remains similar in size to that in the cross‐linked IR without CB. The o‐Ps intensity drastically decreases from 37% without CB to 15% with a CB loading as high as 80 phr. This decline is revealed to exceed the contribution, which is expected only from the decrease in the fraction of the amorphous phase by CB addition, by a factor of 0.37 at the highest CB loading. The additional reduction is related to the generation of a bound rubber layer surrounding the CB fillers with low molecular‐chain mobility where positronium formation is inhibited. The decrease rate is found to represent the volume of this rigid rubber phase and strongly depend on the formation of the CB network structure.

Electrical and Mechanical Properties of Silicone Electrical Conductive Adhesives (ECAs) Filled Carbon Black Treated with 3-Aminotriethoxysilane at Elevated Temperature

In this study, different formulation of silicone filled carbon black electric conducting adhesive (ECAs) were successfully fabricated. Carbon black (CB) was treated with 3-aminotriethoxysilane to improve the surface adhesion by grafting of amide functional groups on the surface of the CB. Various loading of untreated and treated CB (0%,5%,10% and 15%) on silicone ECAs using film casting method were prepared and characterized. The characterization was performed on the conductive adhesive film by using Fourier Transform Infrared Spectroscopy (FTIR), hardness and tensile testing. While for the electrical property, electrochemical impedance spectroscopy (EIS) was investigated. The FTIR spectrums confirmed the surface modification of CB with 3-aminotriethoxysilane and amide functional groups was presence at 1549 cm-1, 1250.7 cm-1, 1126.6 cm-1,976.16 cm-1and 860.02 cm-1corresponding to the N-H, SiO-H, Si-O-Si, C-N and C=C stretching vibrations of the amino groups (-R-NH3+) respectively. The conductivity of the ECAs was dependent on the CB loadings. As the CB loading increased, the conductivity of adhesive conductive film was increased up to 10% of CB loading and decreased when at 15% of CB loading. This is due to the gap distance of interparticle of silicone and CB is high. Whilst the tensile strength of the silicone filled CB increased with increasing of CB content both untreated and treated CB at 0.05954 MPa and 3.3027 MPa respectively. This is supported by hardness testing also showed the same trend with increment of CB loading, the hardness value also increased. The optimum value was found at 42 and 54 for untreated and treated CB respectively. The optimum formulation of electric conductivity was found at 10% loading of CB at 1.75E-08 /cm. The conductivity of ECAs filled CB at elevated temperature exhibits increment trend of untreated/treated CB at temperature of 100 °C to 160 °C however decreased at 180 °C. It is believed that with increasing the temperature, the interparticle average distance increase due to the difference in the thermal expansion of silicone and carbon black. The utilization of treated CB in silicone ECAs improved the conductivity and mechanical properties giving way to a full potential of using CB as filler.

Funnel-Shaped Floating Vessel Oil Skimmer with Joule Heating Sorption Functionality.

Floating vessel-type oil collecting devices based on sorbent materials present potential solutions to oil spill cleanup that require a massive amount of sorbent material and manual labor. Additionally, continuous oil extraction from these devices presents opportunities for highly energy-efficient oil skimmers that use gravity as the oil/water separation mechanism. Herein, a sorbent-based oil skimmer (SOS) is developed with a novel funnel-shaped sorbent and vessel design for efficient and continuous extraction of various oils from the water surface. A carbon black (CB) embedded polydimethylsiloxane (PDMS) sponge material is characterized and used as the sorbent in the SOS. The nanocomposite sponge formulation is optimized for high reusability, hydrophobicity, and rapid oil absorption. Joule heating functionality of the sponge is also explored to rapidly absorb highly viscous oils that are a significant challenge for oil spill cleanup. The optimized sponge material with the highest porosity and 15 wt% CB loading is tested in the SOS for large-scale oil spill extraction tests and shows effective cleaning of oil spilled on the water surface. The SOS demonstrates a high maximum extraction rate of 200 mL/min for gasoline and maintains a high extraction rate performance upon reuse when the sponge funnel is cleaned and dried.

In-situ positron annihilation lifetime measurements of strained isoprene rubber filled with carbon black

The free volume in carbon-black filled isoprene rubber is determined by in-situ positron annihilation lifetime measurements on the rubber subject to tensile strain using ortho-positronium as a probe. The dependence of free volume on the elongation and carbon black loading in the strained state is investigated to clarify the reinforcement mechanism of carbon black in synthetic rubber. Although no change in the ortho-positronium lifetime is detected, the ortho-positronium formation probability sharply decreases with increasing elongation and carbon black concentration in the strained state. The percent reduction is enhanced at high elongations and carbon black loadings. This result indicates the formation of both a bound rubber layer around the CB fillers and regions in the strained rubber phase with oriented molecular chains characterized by lower mobility, where ortho-positronium formation is suppressed.