Effects of the absorbent types on changes in benzo[a]pyrene and volatile compounds in sesame oil

The effects of different absorbent types on changes in benzo[a]pyrene (BaP) and volatiles in sesame oil during filtration processes were investigated using gas chromatography–mass spectrometry analysis. The BaP content was greatly reduced after filtration using powdered activated carbons (activated carbon made from peat: PP, activated carbon made from coconut shell: PC, activated carbon made from wood: PW) in comparison to granular activated carbons (activated carbon made from coconut shell: GC, activated carbon made from wood: GW). The BaP content in sesame oil was also considerably reduced when filtrated with a PW–acid clay mixture in comparison to PW–kaolin and PW–celite mixtures. Most volatile compounds were also greatly reduced after filtration using powdered activated carbons (PP, PC, and PW) in comparison to granular activated carbons (GC and GW). These results might be due to the relatively ionic structure on the surface and internal surface area of absorbent pores.

Porous Electrodeposited Cu as a Potential Electrode for Electrochemical Reduction Reactions of CO2

In the present study, a systematic investigation is performed to assess the relationship between electroplating parameters, pore morphology and internal surface area of copper deposits which are promising to serve as electrodes for electrochemical reduction reactions of carbon dioxide (CO2). A set of porous copper deposits are fabricated with the dynamic hydrogen bubble template method. The microstructural and Brunauer–Emmett–Teller (BET) analysis demonstrate that current density, deposition time, and bath composition control pore size, strut size, and hence surface area which could be as high as 20 m2/g. Selected sets of porous copper electrodes are then employed in the electrochemical reduction reaction test to determine their conversion performance in comparison to a monolithic copper surface. From the gas chromatography (GC) and nuclear magnetic resonance (NMR) analysis, porous copper is shown to provide higher rates of production of some important chemicals, as compared to copper foil electrodes. Porous copper with fern-like morphology serves as a promising electrode that yields relatively high amounts of acetaldehyde, acetate and ethanol. The study thus presents the opportunities to enhance the electrochemical reduction reaction of CO2 through microstructural engineering of the copper surface, which benefits both CO2 reduction and generation of chemical products of high value.

Impact of Nanoparticle Consolidation on Charge Separation Efficiency in Anatase TiO2 Films

Mesoporous films and electrodes were prepared from aqueous slurries of isolated anatase TiO2 nanoparticles. The resulting layers were annealed in air at temperatures 100°C ≤ T ≤ 450°C upon preservation of internal surface area, crystallite size and particle size. The impact of processing temperature on charge separation efficiency in nanoparticle electrodes was tracked via photocurrent measurements in the presence of methanol as a hole acceptor. Thermal annealing leads to an increase of the saturated photocurrent and thus of the charge separation efficiency at positive potentials. Furthermore, a shift of capacitive peaks in the cyclic voltammograms of the nanoparticle electrodes points to the modification of the energy of deep traps. Population of these traps triggers recombination possibly due to the action of local electrostatic fields attracting photogenerated holes. Consequently, photocurrents saturate at potentials, at which deep traps are mostly depopulated. Charge separation efficiency was furthermore investigated for nanoparticle films and was tracked via the decomposition of hydrogen peroxide. Our observations evidence an increase of charge separation efficiency upon thermal annealing. The effect of particle consolidation, which we associate with minute atomic rearrangements at particle/particle contacts, is attributed to the energetic modification of deep traps and corresponding modifications of charge transport and recombination, respectively.

Manufacturing of Closed Impeller for Mechanically Pump Fluid Loop Systems Using Selective Laser Melting Additive Manufacturing Technology

In the space industry, the market demand for high-pressure mechanically pumped fluid loop (MPFL) systems has increased the interest for integrating advanced technologies in the manufacturing process of critical components with complex geometries. The conventional manufacturing process of a closed impeller encounters different technical challenges, but using additive manufacturing (AM) technology, the small component is printed, fulfilling the quality requirements. This paper presents the Laser Powder Bed Fusion (LPBF) process of a closed impeller designed for a centrifugal pump integrated in an MPFL system with the objective of defining a complete manufacturing process. A set of three closed impellers was manufactured, and each closed impeller was subjected to dimensional accuracy analysis, before and after applying an iterative finishing process for the internal surface area. One of the impellers was validated through non-destructive testing (NDT) activities, and finally, a preliminary balancing was performed for the G2.5 class. The process setup (building orientation and support structure) defined in the current study for a pre-existing geometry of the closed impeller takes full advantages of LPBF technology and represents an important step in the development of complex structural components, increasing the technological readiness level of the AM process for space applications.

Studies on the Behavior of Epoxy Polymer Matrix Reinforced by Carbon Particles obtained from Pyrolysis of Mixed Waste Plastic: A Review

Commercial Carbon black is produced by thermal cracking of natural gas but nowadays the prices of carbon black are going down at a very sharp rate. The low prices of carbon black resulted in the search for low cost raw material. Most of the researchers focused on inexpensive agricultural waste such as shells of coconut, palm or bamboo. Pyrolysis of plastics is providing an excellent opportunity to manufacture carbon and presents an effective way to recycle non degradable plastics. Carbon element has revolutionized entire material science studies as it provides well developed pore structure and a very high internal surface area. It finds application as adsorbent, catalyst or electrode. Researchers like carbon black particles as they can be reinforced into polymer matrices providing a huge opportunity to prepare composites. The properties of these carbon black reinforced composites hugely depend on their origin, processing conditions and chemical treatments. The addition of these carbon black fillers obtained from plastics into polymer composites results in the formation of different microstructures and thus providing different types of composites based on shape, particle sizes and source of origin. The high concentration of carbon fillers results in making highly hydrophobic composites and finds application in making pipelines for extreme weather conditions.

Minimizing the Use of Polyethene inside Paper Coffee Cups

Although made of paper, most coffee cups are not recycled because of the polyethene covering their internal surface area (1, 2). Instead, they are sent to landfills where they break down into microplastics and negatively impact organisms after entering the food chain (2, 3). This is an especially alarming issue due to the extensive usage of paper coffee cups around the world. As a result, many global companies have been searching for an eco-friendly cup that eliminates the use of polyethene, a challenge that remains unresolved to this day (9). While the search continues, many businesses have relied on temporary strategies to reduce polyethene production until a design that eliminates its use is developed (9, 10, 11, 12). Two major methods include public awareness and promotion of reusable cups (2). However, these approaches have only resulted in minor changes due to their reliance on customer cooperation (2). To guarantee polyethene reduction, this report proposes a strategy that is independent of customer cooperation. This method determines the dimensions (i.e., height and bottom radius) that minimize the amount of polyethene needed to coat the internal surface area of a cup, while keeping the cup’s volume and lid size (i.e., top radius) the same. The resulting equation gives the surface area of the cup while the root to the first derivate of this equation corresponds to the optimal bottom radius. Using a derived equation for height, the optimal cup height is determined as well. To highlight its proper implementation, this strategy is applied to a Starbucks Grande coffee cup as a model for other companies to follow.

Multifunctional Liquid Crystal Nanoparticles for Cancer Therapy

Cancer is the second foremost reason for worldwide death, affecting every country of the globe. However, 70% of cancer-related death was reported from low- and middle-income nations. Delay in the detection and intervention of therapeutic agents in cancer patients also promoted a cancer-related mortality index. Currently, numerous nanomedicines are under development for advancing tumor diagnosis and therapeutic capability. Recently, liquid crystalline nanoparticles (LCNPs) have emerged as an attractive drug delivery system for both intravenous and non-intravenous applications. The widely explored LCNPs for cancer therapy include cubosomes and hexosomes. They have significant advantages over other drug delivery system, which includes, high internal surface area, unique solubilization properties and sustained release of entrapped drug molecules and co-loading of imaging and therapeutic agents in a single system. In this review, we have briefly discussed the advantages of LCNPs, preparation methods, and their multifunctional role in treating various cancers.

Porous Silicon Optical Devices: Recent Advances in Biosensing Applications

This review summarizes the leading advancements in porous silicon (PSi) optical-biosensors, achieved over the past five years. The cost-effective fabrication process, the high internal surface area, the tunable pore size, and the photonic properties made the PSi an appealing transducing substrate for biosensing purposes, with applications in different research fields. Different optical PSi biosensors are reviewed and classified into four classes, based on the different biorecognition elements immobilized on the surface of the transducing material. The PL signal modulation and the effective refractive index changes of the porous matrix are the main optical transduction mechanisms discussed herein. The approaches that are commonly employed to chemically stabilize and functionalize the PSi surface are described.

Heat-Up Performance of Catalyst Carriers—A Parameter Study and Thermodynamic Analysis

This study investigates geometric parameters of commercially available or recently published models of catalyst substrates for passenger vehicles and provides a numerical evaluation of their influence on heat-up behavior. Parameters considered to have a significant impact on the thermal economy of a monolith are: internal surface area, heat transfer coefficient, and mass of the converter, as well as its heat capacity. During simulation experiments, it could be determined that the primary role is played by the mass of the monolith and its internal surface area, while the heat transfer coefficient only has a secondary role. Furthermore, an optimization loop was implemented, whereby the internal surface area of a commonly used substrate was chosen as a reference. The lengths of the thin wall and high cell density monoliths investigated were adapted consecutively to obtain the reference internal surface area. The results obtained by this optimization process contribute to improving the heat-up performance while simultaneously reducing the valuable installation space required.

Manufacturing of hydrogels from never-dried microcrystalline cellulose by high-pressure mechanical treatment

Microcrystalline cellulose-based hydrogels were made using never-dried MCC (AaltoCellTM) as a raw material for a high-pressure mechanical treatment consisting of one to five passes at 700 bars. The effects of the mechanical treatment on the crystalline structure, morphology, geometrical dimensions, and specific surface area as well as rheological properties of the manufactured cellulose gel product were investigated. The results indicated that the process detached part of the crystalline area of the cellulose, resulting in loose particle architecture, increased surface area and porosity, and thus more accessible and reactive material. Due to the creation of the new internal surface area and porosity, more hydrogen bonds were formed between the cellulose particles, consequently creating more stable cellulose hydrogel-like slurries. The properties of the produced hydrogels were greatly influenced by the number of the treatment passes through the process equipment. Several passes through the process produced stronger cellulose hydrogels capable of retaining more water.