Porous Carbon Nanoparticles Research Articles

A comparative study of antioxidant-loaded carbon nanoparticles as drug delivery vehicles

Chronic obstructive pulmonary disease (COPD) describes chronic lung diseases that cause limitations in lung airflow. Reactive oxygen species (ROS) play a central role in causing COPD and scavenging of ROS holds great promise to alleviate the symptoms of COPD. Antioxidant proteins such as catalase are good therapeutic drug candidates; however, they are easily degraded by proteases in vivo. Here, we investigated the characteristics of carbon nanoparticles as vehicles for delivering antioxidant proteins to macrophages. A direct comparison using catalase was conducted from zero to three dimensional carbon nanoparticles, namely: fullerene (zero dimensional (0D)), carbon nanotubes (CNTs, one dimensional (1D)), graphene oxide (GO, two dimensional (2D)), and graphene aerogel (GA, three dimensional (3D)). Over 90% of catalase was encapsulated in CNTs, GO, and GA. GA released less than 3% catalase in 24 hours, which is useful for long-term release. Fullerene delivered catalase inside macrophages with high efficiency although the encapsulation of catalase in the fullerene was 39.7%. Functionalization of carbon nanoparticles can modify the chemical properties that affect the characteristics of drug delivery vehicles. The release rate of catalase from functionalized carbon nanoparticles, CNTs with 2.0 wt% (percent by weight) of –COOH and GO, is 15–20% in 4 hours, which is much higher than GA. As drug delivery vehicles, carbon nanoparticles are very promising due to their high loading efficiency of therapeutic drugs and tunable surface properties. We also anticipate numerous applications of porous carbon nanoparticles for treating lung diseases, since low density nanoparticles can reach the deep lung efficiently.

Catalyst free silica templated porous carbon nanoparticles from bio-waste materials

Porous Carbon Nanoparticles (PCNs) with well-developed microporosity were obtained from bio-waste oil palm leaves (OPL) using single step pyrolysis in nitrogen atmosphere at 500-600 °C in tube-furnace without any catalysis support. The key approach was using silica (SiO2) bodies of OPL as a template in the synthesis of microporous carbon nanoparticles with very small particle sizes of 35-85 nm and pore sizes between 1.9-2 nm.

Correction: Corrigendum: Porous Carbon Nanoparticle Networks with Tunable Absorbability

Porous carbon materials with high specific surface areas and superhydrophobicity have attracted much research interest due to their potential application in the areas of water filtration, water/oil separation, and oil-spill cleanup. Most reported superhydrophobic porous carbon materials are fabricated by complex processes involving the use of catalysts and high temperatures but with low throughput. Here, we present a facile single-step method for fabricating porous carbon nanoparticle (CNP) networks with selective absorbability for water and oils via the glow discharge of hydrocarbon plasma without a catalyst at room temperature. Porous CNP networks were grown by the continuous deposition of CNPs at a relatively high deposition pressure. By varying the fluorine content, the porous CNP networks exhibited tunable repellence against liquids with various degrees of surface tension. These porous CNP networks could be applied for the separation of not only water/oil mixtures but also mixtures of liquids with different surface tension levels.

Porous Carbon Nanoparticle Networks with Tunable Absorbability

Porous carbon materials with high specific surface areas and superhydrophobicity have attracted much research interest due to their potential application in the areas of water filtration, water/oil separation, and oil-spill cleanup. Most reported superhydrophobic porous carbon materials are fabricated by complex processes involving the use of catalysts and high temperatures but with low throughput. Here, we present a facile single-step method for fabricating porous carbon nanoparticle (CNP) networks with selective absorbability for water and oils via the glow discharge of hydrocarbon plasma without a catalyst at room temperature. Porous CNP networks were grown by the continuous deposition of CNPs at a relatively high deposition pressure. By varying the fluorine content, the porous CNP networks exhibited tunable repellence against liquids with various degrees of surface tension. These porous CNP networks could be applied for the separation of not only water/oil mixtures but also mixtures of liquids with different surface tension levels.

In situ synthesis of binded, thick and porous carbon nanoparticle dye sensitized solar cell counter electrode with nickel gel as catalyst source

A TiO2-embedded NiCl2 gel is prepared and used as growth catalyst to in situ synthesize binded, thick and porous carbon nanoparticles (CNPs) on Ti foil substrate with a simple flame synthesis method for dye sensitized solar cell (DSSC) counter electrode (CE) applications. The viscous gel catalyst can hold sufficient NiCl2 coated on substrate to make CNP layer thick. The embedded TiO2 can effectively separate the abundant NiCl2 components to active the Ni catalyst for CNP growth and then make CNP layer become porous. In addition, the TiO2 components can bind the porous CNP products to make them conductive. With an optimized TiO2 fraction, the CE shows high catalytic ability and electrical conductivity. By applying this CNP CE for DSSC, a photovoltaic conversion efficiency of 6.6% is achieved, which exceeds 6.5% of a reference cell using costly platinum as CE. Furthermore, the CNP structure is demonstrated beneficial to carrier transport by a mass transfer model. This easy and effective preparation method may have a potential application in general nanomaterial preparation.

Nafion ® nanofibers and their effect on polymer electrolyte membrane fuel cell performance

Current fuel cell research is focused on reducing manufacturing costs by reducing platinum catalyst loading without sacrificing performance. Although improvements have been demonstrated by using platinum supported on porous carbon nanoparticles, significant losses in “active” platinum surface area within the catalyst layer (CL) still occur. Optimizing the reactant gas/Nafion ®/platinum triple phase boundary (TPB) in the CL (i.e., CL morphology) will result in increased “active” catalyst area and overall fuel cell performance. In this study, the effect of temperature on the formation of Nafion ® nanofibers in the CL during fuel cell operation and its subsequent improvement on fuel cell performance was clearly characterized. Post mortem scanning electron micrographs clearly show that Nafion ® nanofibers improve the TPB, where Nafion ® nanofibers act as a more efficient proton transport route from the catalyst particles to the polymer electrolyte membrane reducing ohmic and mass transport resistance.