Semiconducting and Metallic Polymers: The Fourth Generation of Polymeric Materials

MRS Bulletin ◽  
2001 ◽  
Vol 26 (11) ◽  
pp. 900-904 ◽  
Author(s):  
Alan J. Heeger

Prior to receiving the Nobel Prize in chemistry in 2000 for my work in polymers, polymer science had been recognized three times. The first Nobel Prize in chemistry for polymer science was awarded in 1953 to Hermann Staudinger, for his pioneering work in the 1920s. At that time, the concept of macromolecules was new, and his ideas were controversial. However, the data prevailed, and he was awarded the Prize “for his discoveries in the field of macromolecular chemistry.” The next major event in polymer science was the discovery and invention of nylon by Wallace Carothers at the Dupont Company in 1935. Although Carothers died as a young man, his discoveries created an industry. I have little doubt that his work was deserving of a Nobel Prize and probably would have been awarded. The next related Prize went to Karl Ziegler and Giulio Natta in 1963 for their work on polymer synthesis in the 1950s. The Ziegler–Natta catalysts made possible the large-scale production of polymers such as polypropylene. They were awarded the Nobel Prize in chemistry “for their discoveries in the field of chemistry and technology of high polymers.” In 1974, the Prize for chemistry went to Paul J. Flory, who was a giant in this field. He was awarded the Nobel “for his fundamental achievements, both theoretical and experimental, in the physical chemistry of macromolecules.”

2019 ◽  
Vol 9 (8) ◽  
pp. 1682 ◽  
Author(s):  
Steffy J. Arteaga-Díaz ◽  
Samir I. Meramo-Hurtado ◽  
Jeffrey León-Pulido ◽  
Antonio Zuorro ◽  
Angel D. González-Delgado

Nanoparticles are materials with special properties that can be applied in different fields, such as medicine, engineering, food industry and cosmetics. The contributions regarding the synthesis of different types of nanoparticles have allowed researchers to determine a special group of nanoparticles with key characteristics for several applications. Magnetite nanoparticles (Fe3O4) have attracted a significant amount of attention due to their ability to improve the properties of polymeric materials. For this reason, the development of novel/emerging large scale processes for the synthesis of nanomaterials is a great and important challenge. In this work, an environmental assessment of the large scale production of magnetite via coprecipitation was carried out with the aim to evaluate its potential impact on the environment at a processing capacity of 806.87 t/year of magnetite nanoparticles. The assessment was performed using a computer-aided tool based on the Waste Reduction Algorithm (WAR). This method allows us to quantify the impacts generated and classify them into eight different categories. The process does not generate any negative impacts that could harm the environment. This assessment allowed us to identify the applicability of the large scale production of magnetite nanoparticles from an environmental viewpoint.


1949 ◽  
Vol 22 (2) ◽  
pp. 392-401
Author(s):  
L. B. Morgan

Abstract During the last few years considerable advances have been made in the theory of polymerization processes, and these have a direct bearing on the manufacture of synthetic rubbers and plastics and the properties of the various products of this type that are now handled by the rubber industry. The most important industrial process involves emulsion polymerization. This is used in the production of types, such as GR-S, Perbunan, and Neoprene, and also in the production of polyvinyl chloride. World production of these emulsion polymeric materials is in the region of hundreds of thousands of tons per annum, and the process is probably one of the more important chemical manufactures developed in the last decade. No large manufacture of synthetic rubber has been developed in Great Britain, mainly because of war-time exigencies and economic considerations, and the only significant contribution made by British chemical industry to alleviate the war-time scarcity of natural rubber was to develop a large-scale production of polyvinyl chloride to satisfy the requirements of the cable trade. There has, however, been some research activity on synthetic rubber in this country since 1935 in the laboratories of the Dyestuffs Division of Imperial Chemical Industries, Ltd. Activity in the main was concentrated on the diene emulsion interpolymer types and a large number of second components were examined for interpolymerization with both butadiene and chloroprene. Comparatively few interpolymerize to give rubbers with reasonably good vulcanizate properties. These have been disclosed in the patent literature. Parallel work was being carried out in the laboratories of I. G. Farbenindustrie and later in America, and the results of much of this have now appeared in the technical literature and in the accounts that are now available on German war-time activities. The general conclusions were similar.


1993 ◽  
Vol 32 (1) ◽  
pp. 129-131
Author(s):  
Naureen Talha

The literature on female labour in Third World countries has become quite extensive. India, being comparatively more advanced industrially, and in view of its size and population, presents a pictures of multiplicity of problems which face the female labour market. However, the author has also included Mexico in this analytical study. It is interesting to see the characteristics of developing industrialisation in two different societies: the Indian society, which is conservative, and the Mexican society, which is progressive. In the first chapter of the book, the author explains that he is not concerned with the process of industrialisation and female labour employed at different levels of work, but that he is interested in forms of production and women's employment in large-scale production, petty commodity production, marginal small production, and self-employment in the informal sector. It is only by analysis of these forms that the picture of females having a lower status is understood in its social and political setting.


2018 ◽  
Vol 15 (4) ◽  
pp. 572-575 ◽  
Author(s):  
Ponnusamy Kannan ◽  
Samuel I.D. Presley ◽  
Pallikondaperumal Shanmugasundaram ◽  
Nagapillai Prakash ◽  
Deivanayagam Easwaramoorthy

Aim and Objective: Itopride is a prokinetic agent used for treating conditions like non-ulcer dyspepsia. Itopride is administered as its hydrochloride salt. Trimethobenzamide is used for treating nausea and vomiting and administered as its hydrochloride salt. The aim is to develop a novel and environmental friendly method for large-scale production of itopride and trimethobenzamide. Materials and Methods: Itopride and trimethobenzamide can be prepared from a common intermediate 4- (dimethylaminoethoxy) benzyl amine. The intermediate is prepared from one pot synthesis using Phyrdroxybenzaldehye and zinc dust and further reaction of the intermediate with substituted methoxy benzoic acid along with boric acid and PEG gives itopride and trimethobenzamide. Results: The intermediate 4-(dimethylaminoethoxy) benzylamine is prepared by treating p-hydroxybenzaldehyde and 2-dimethylaminoethyl chloride. The aldehyde formed is treated with hydroxylamine hydrochloride. The intermediate is confirmed by NMR and the purity is analysed by HPLC. Conclusion: Both itopride and trimethobenzamide were successfully synthesized by this method. The developed method is environmental friendly, economical for large-scale production with good yield and purity.


Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 241
Author(s):  
Shaden A. M. Khalifa ◽  
Eslam S. Shedid ◽  
Essa M. Saied ◽  
Amir Reza Jassbi ◽  
Fatemeh H. Jamebozorgi ◽  
...  

Cyanobacteria are photosynthetic prokaryotic organisms which represent a significant source of novel, bioactive, secondary metabolites, and they are also considered an abundant source of bioactive compounds/drugs, such as dolastatin, cryptophycin 1, curacin toyocamycin, phytoalexin, cyanovirin-N and phycocyanin. Some of these compounds have displayed promising results in successful Phase I, II, III and IV clinical trials. Additionally, the cyanobacterial compounds applied to medical research have demonstrated an exciting future with great potential to be developed into new medicines. Most of these compounds have exhibited strong pharmacological activities, including neurotoxicity, cytotoxicity and antiviral activity against HCMV, HSV-1, HHV-6 and HIV-1, so these metabolites could be promising candidates for COVID-19 treatment. Therefore, the effective large-scale production of natural marine products through synthesis is important for resolving the existing issues associated with chemical isolation, including small yields, and may be necessary to better investigate their biological activities. Herein, we highlight the total synthesized and stereochemical determinations of the cyanobacterial bioactive compounds. Furthermore, this review primarily focuses on the biotechnological applications of cyanobacteria, including applications as cosmetics, food supplements, and the nanobiotechnological applications of cyanobacterial bioactive compounds in potential medicinal applications for various human diseases are discussed.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1940
Author(s):  
Muhammad Usman Naseer ◽  
Ants Kallaste ◽  
Bilal Asad ◽  
Toomas Vaimann ◽  
Anton Rassõlkin

This paper presents current research trends and prospects of utilizing additive manufacturing (AM) techniques to manufacture electrical machines. Modern-day machine applications require extraordinary performance parameters such as high power-density, integrated functionalities, improved thermal, mechanical & electromagnetic properties. AM offers a higher degree of design flexibility to achieve these performance parameters, which is impossible to realize through conventional manufacturing techniques. AM has a lot to offer in every aspect of machine fabrication, such that from size/weight reduction to the realization of complex geometric designs. However, some practical limitations of existing AM techniques restrict their utilization in large scale production industry. The introduction of three-dimensional asymmetry in machine design is an aspect that can be exploited most with the prevalent level of research in AM. In order to take one step further towards the enablement of large-scale production of AM-built electrical machines, this paper also discusses some machine types which can best utilize existing developments in the field of AM.


Author(s):  
Yuting Luo ◽  
Zhiyuan Zhang ◽  
Fengning Yang ◽  
Jiong Li ◽  
Zhibo Liu ◽  
...  

Large-scale production of green hydrogen by electrochemical water splitting is considered as a promising technology to address critical energy challenges caused by the extensive use of fossil fuels. Although nonprecious...


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Rozina Rashid ◽  
Muhammad Sohail

AbstractThe capacity of different Bacillus species to produce large amounts of extracellular enzymes and ability to ferment various substrates at a wide range of pH and temperature has placed them among the most promising hosts for the industrial production of many improved and novel products. The global interest in prebiotics, for example, xylooligosaccharides (XOs) is ever increasing, rousing the quest for various forms with expanded productivity. This article provides an overview of xylanase producing bacilli, with more emphasis on their capacity to be used in the production of the XOs, followed by the purification strategies, characteristics and application of XOs from bacilli. The large-scale production of XOs is carried out from a number of xylan-rich lignocellulosic materials by chemical or enzymatic hydrolysis followed by purification through chromatography, vacuum evaporation, solvent extraction or membrane separation methods. Utilization of XOs in the production of functional products as food ingredients brings well-being to individuals by improving defense system and eliminating pathogens. In addition to the effects related to health, a variety of other biological impacts have also been discussed.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1706
Author(s):  
Zacharias Viskadourakis ◽  
Argiri Drymiskianaki ◽  
Vassilis M. Papadakis ◽  
Ioanna Ioannou ◽  
Theodora Kyratsi ◽  
...  

In the current study, polymer-based composites, consisting of Acrylonitrile Butadiene Styrene (ABS) and Bismuth Antimony Telluride (BixSb2−xTe3), were produced using mechanical mixing and hot pressing. These composites were investigated regarding their electrical resistivity and Seebeck coefficient, with respect to Bi doping and BixSb2-xTe3 loading into the composite. Experimental results showed that their thermoelectric performance is comparable—or even superior, in some cases—to reported thermoelectric polymer composites that have been produced using other complex techniques. Consequently, mechanically mixed polymer-based thermoelectric materials could be an efficient method for low-cost and large-scale production of polymer composites for potential thermoelectric applications.


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