When certain polymers are heat-treated beyond their degradation temperature in the absence of oxygen, they pass through a semi-solid phase, followed by the loss of heteroatoms and the formation of a ...solid carbon material composed of a three-dimensional graphenic network, known as glassy (or glass-like) carbon. The thermochemical decomposition of polymers, or generally of any organic material, is defined as pyrolysis. Glassy carbon is used in various large-scale industrial applications and has proven its versatility in miniaturized devices. In this article, micro and nano-scale glassy carbon devices manufactured by (i) pyrolysis of specialized pre-patterned polymers and (ii) direct machining or etching of glassy carbon, with their respective applications, are reviewed. The prospects of the use of glassy carbon in the next-generation devices based on the material's history and development, distinct features compared to other elemental carbon forms, and some large-scale processes that paved the way to the state-of-the-art, are evaluated. Selected support techniques such as the methods used for surface modification, and major characterization tools are briefly discussed. Barring historical aspects, this review mainly covers the advances in glassy carbon device research from the last five years (2013⁻2018). The goal is to provide a common platform to carbon material scientists, micro/nanomanufacturing experts, and microsystem engineers to stimulate glassy carbon device research.
During the last few decades, enormous emissions of greenhouse gases (GHGs) into the atmosphere by human activities, lead to global warming. Thus, it becomes essential to prevent the excessive ...emission or to develop new technologies to avoid successive accumulation of CO2. Biological systems in nature have the capability to fix the atmospheric CO2 but in the urban and industrially developed areas where a rate of CO2 emission is very high, the biological system cannot capture and utilize the whole CO2. Various chemicals and synthetic materials with CO2 absorbing property are not eco-friendly or these are very expensive. Carbonic anhydrase (CA) is the fastest known enzymes containing zinc in its active site, convert CO2 to bicarbonate ions. It is one of a potent biological catalyst for CO2 conversion. Thus, in order to reduce the level of CO2 the biocatalytic properties of microbial CA can be exploited. Literature survey showed that, more than fifty different microbial CAs have been explored for CO2 sequestration. The major advantages of CA to sequester CO2 are economic viability and carbonation of CO2 at a low concentration. Despite the higher rate of catalysis, the stability of CA is a major challenge for its industrial application. These difficulties have been partly solved by immobilizing the CA onto the bio-inspired surface, biochar, alginate, polyurethane foam and variety of nano-textured materials. A combination of enzyme and material which jointly capture and convert the CO2 into either carbon-rich compound of economic value or reduced carbon derivatives will plausibly energize the CO2 utilization. In this review, we discussed the recent advances in chemical and materials used for CO2 capture, their advantages and limitations, utilization of microbial CA for CO2 conversion, and its various applications.
•Carbonic anhydrase is the fastest known enzymes which convert carbon dioxide to bicarbonate ions.•CA catalyzes the reaction very fast but the stability of CA is a major challenge which hinders its industrial application.•An integrated or hybrid system will overcome the limitation of one agent chemical, material, or biological for capturing the CO2.•Thus, cumulatively in a hybrid system which contain all these CO2 capturing agents will surely prove to be key to mitigate climate change.
Pencil is one of the most widely used electrode material in electrochemical sensing of various organic and inorganic species with significant lower detection limit. Due to their lower background ...currents, superior sensitivity, reproducibility, amendable electroactive surface area, cost effective and ease of disposability, pencil graphite electrode has gain considerable attention in recent years. It signifies a viable substitute to other expensive traditional electrodes such as Glassy carbon, Gold, Boron-doped-diamond, platinum etc. This review addresses a wide overview of the characteristics, preparations, pre-treatment and application of bare PGE and in combination with other modifier as electrochemical sensors for the quantification of organic pollutants specifically pharmaceuticals and pesticides.
•The current review article embraces the history along with the difference of supercapacitors with fuel cells, capacitors, and batteries.•The detailed explanation of fabrication of supercapacitors ...i.e. proper selection of electrode and electrolyte material, separator and current collector.•Each electrolyte type that is, aqueous, organic, redox additive and ionic liquids is thoroughly discussed.•Electrochemical characterization techniques such as Cyclic Voltammetry (CV), Galvanostatic Charge Discharge (GCD) and Electrochemical Impedance Spectroscopy (EIS) are also briefly discussed here.•Merit/challenges and future prospect of these systems in energy storage applications are summarized.
Energy storage plays crucial role to complete global and economical requirements of human beings. Supercapacitor act as promising candidate for energy storage applications due to its astonishing properties like - high power density, remarkable crystallinity, large porosity, elongated life-cycle, exceptional chemical & thermal stability, framework diversity and high specific surface area. The current review article embraces the history along with the difference of supercapacitors with fuel cells, capacitors, and batteriesand detailed explanation of fabrication of supercapacitors i.e. proper selection of electrode and electrolyte material, separator and current collector. As a supercapacitor electrode material, several carbon-based materials, metal-oxides, and metal–organic frameworks have been briefly mentioned here. The current review article also discusses the supercapacitor components and various types of electrolytes. Electrochemical characterization techniques such as Cyclic Voltammetry (CV), Galvanostatic Charge Discharge (GCD) and Electrochemical Impedance Spectroscopy (EIS) are also briefly discussed here. Furthermore, this article outlines the current issues as well as potential solutions for upcoming time period.
Glassy carbon is derived from synthetic organic polymers that undergo the process of coking during their pyrolysis. Polymer-to-carbon conversion (hereafter referred to as PolyCar) also takes place in ...nature, and is indeed responsible for the formation of various naturally occurring carbon allotropes. In the last few decades the PolyCar concept has been utilized in technological applications, i.e., specific polymers are patterned into the desired shapes and intentionally converted into carbon by a controlled heat-treatment. Device fabrication using glassy carbon is an excellent example of the use of the PolyCar process in technology, which has rapidly progressed from conventional to micro- and nanomanufacturing. While the technique itself is simple, one must have a good understanding of the carbonization mechanism of the polymer, which in turn determines whether or not the resulting material will be glassy carbon. Publications that comprise this special issue shed light on several aspects of the formation, properties and performance of glassy carbon in the cutting-edge technological applications. The results of detailed material characterization pertaining to two important research areas, namely neural electrodes and precision glass molding, are presented as examples. I hope that the readers will enjoy as well as benefit from this collection.
Plastics have been one of the highly valued materials and it plays an significant role in human's life such as in food packaging and biomedical applications. Bioplastic materials can gradually work ...as a substitute for various materials based on fossil oil. The issue like sustainability and environmental challenges which occur due to manufacturing and disposal of synthetic plastics can be conquering by bio-based plastics. Feathers are among the most inexpensive abundant, and renewable protein sources. Feathers disposal to the landfills leads to environmental pollutions and it results into wastage of 90% of protein raw material. Keratin is non-burning hydrophilic, and biodegradable due to which it can be applicable in various ways via chemical processing. Main objective of this research is to synthesis bioplastic using keratin from chicken feathers. Extracted keratin solution mixed with different concentration of glycerol (2 to 10%) to produce plastic films. The mixture was stirred under constant magnetic stirring at 60 °C for 5 h. The mixtures are then poured into aluminum weighing boat and dried in an oven at 60 °C for 24 h. The mechanical properties of the samples were tested and the physic-chemical properties of the bioplastic were studied. According to the results, Scanning Electron Microscopy test showed good compatible morphologies without holes, cavity and edge. The difference in chemical composition was analyzed using Fourier transform infrared spectroscopy (FTIR). The samples were also characterized by thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-Ray diffraction (XRD) to check the thermal and crystallinity properties. Other than that, bioplastic made up from keratin with 2% of glycerol has the best mechanical and thermal properties. According to biodegradability test, all bioplastic produced are proven biodegradable. Therefore, the results showed possible application of the film as an alternative to fossil oil based materials which are harmful to the environment.
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•Extraction of keratin from feather biomass using chemical methods•Glycerol aided synthesis of degradable bioplastic film using feather keratin.•Characterization of bioplastic film using different analytical methods•Stability and durability of synthesized bioplastic film
•Staggered treatment of plum fruit has been reported for the first time.•Staggered treatment of ‘Santa Rosa’ plum after 7, 14 and 21 days interval was effective and enhanced postharvest life.•The ...most effective treatment was SA @ 2.0mM followed by NO @ 0.5mM.•The staggered I, II and III set maintained shelf life of plum up to 10, 6 and 4 days, respectively in supermarket storage conditions.•This may assist in taking decisions regarding beneficial effects of postharvest treatments if not applied immediately after harvest.
The present investigation was conducted to study the effect of staggered removal of cold stored (2°C) plums at 7, 14 and 21 days interval and their subsequent treatment with salicylic acid (SA), nitric oxide (NO) and ethylene absorbent (EA) sachets. The fruit were then stored at supermarket conditions (20±1°C and 90±5% RH) with the objective to know whether delayed EA, SA and NO treatments still have significant beneficial effects on the plum fruit quality. The observations on different physiological and biochemical parameters were taken at 2 days interval. The results showed that staggered treatments enhanced postharvest life and maintained fruit quality. We observed that SA-treated plums showed the highest fruit firmness and lowest decay losses when plums were either removed on 7th, 14th or 21st days of cold storage. Furthermore, SA-treated fruit exhibited lowest rates of respiration and ethylene evolution; phenylalanine ammonia lyase and pectin methyl esterase activities; minimum malondialdehyde content and lowest electrolyte leakage in comparison to those treated either with NO or packed with EA sachets or control fruit. In conclusion, ‘Santa Rosa’ plum removed after 7th (staggered-I), 14th (staggered-II) and 21st day (staggered-III) from cold storage maintained a shelf life of 10, 6 and 4 days, respectively at subsequent supermarket storage conditions. The overall results submit that even if the plums are not treated immediately or within few days after harvest and placed as such in cold store, they can be still treated with SA, NO or in-package ethylene absorbent (EA) treatment for beneficial postharvest influences.
In the broad range of human diseases, thrombo-inflammation appears as a clinical manifestation. Clinically, it is well characterized in context of superficial thrombophlebitis that is recognized as ...thrombosis and inflammation of superficial veins. However, it is more hazardous when developed in the microvasculature of injured/inflamed/infected tissues and organs. Several diseases like sepsis and ischemia-reperfusion can cause formation of microvascular thrombosis subsequently leading to thrombo-inflammation. Thrombo-inflammation can also occur in cases of antiphospholipid syndrome, preeclampsia, sickle cell disease, bacterial and viral infection. One of the major contributors to thrombo-inflammation is the loss of normal anti-thrombotic and anti-inflammatory potential of the endothelial cells of vasculature. This manifest itself in the form of dysregulation of the coagulation pathway and complement system, pathologic platelet activation, and increased recruitment of leukocyte within the microvasculature. The role of platelets in hemostasis and formation of thrombi under pathologic and non-pathologic conditions is well established. Platelets are anucleate cells known for their essential role in primary hemostasis and the coagulation pathway. In recent years, studies provide strong evidence for the critical involvement of platelets in inflammatory processes like acute ischemic stroke, and viral infections like Coronavirus disease 2019 (COVID-19). This has encouraged the researchers to investigate the contribution of platelets in the pathology of various thrombo-inflammatory diseases. The inhibition of platelet surface receptors or their intracellular signaling which mediate initial platelet activation and adhesion might prove to be suitable targets in thrombo-inflammatory disorders. Thus, the present review summarizes the concept and mechanism of platelet signaling and briefly discuss their role in sterile and non-sterile thrombo-inflammation, with the emphasis on role of platelets in COVID-19 induced thrombo-inflammation. The aim of this review is to summarize the recent developments in deciphering the role of the platelets in thrombo-inflammation and discuss their potential as pharmaceutical targets.
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