Exploiting a powerful science base

Europe is striving to become the world's leading knowledge‐based economy but those in the corridors of power do not recognise the contribution chemistry can make.     

Green and one-pot synthesis of novel amidoalkyl naphthols using triethanolammonium acetate [(OHCH2CH2)3NH][OAc]) ionic liquid and their anti-H.pylori activity

Research on Chemical Intermediates - Nearly half of the world's population have been infected with Helicobacter pylori (H. pylori) which is known as the main cause of chronic gastritis,...     

5. Applications of cellulose acetate 5.1 Cellulose acetate in textile application

The first cellulose acetate fiber, commonly referred to as acetate, was produced in Europe in 1918 and on a large scale in the United States of America in 1924 making acetate the second man-made fiber to be produced.¹ The usage of acetate worldwide peaked at a consumption of approximately 400 kilotons in the early 1970's.² In the past three decades the use of acetate fiber has declined as fabric manufacturers moved to lower costs manmade fibers such as polyester. Manufacturers of acetate have worked aggressively to reduce their cost while maintaining product quality. These efforts have had some reward, leading to acetate's categorization as a niche fiber. As such, cellulose acetate represents less than one percent of the world's total fiber consumption as compared to cotton at over a third³ of the world's consumption and polyester at around a fourth.⁴ Acetate has been used and continues to be used in many different textile applications because of its attributes and good textile processing performance. It is used in woven fabrics, knits and braids. It is found in multiple applications including medical gauze, ribbons, coffin linings, home furnishings, woven velvets, tricot knits, men's linings, circular knits, woven satins, woven fashion, women's linings. It is found in a variety of deniers, lusters, colors, finishes, compactions types and package sizes. It is often blended with other fibers to make combination yarns.     

Deep inelastic scattering: Status and future

Deep inelastic lepton–nucleon scattering (DIS) is briefly characterised in its historical role in establishing the standard model of the electroweak and strong interactions. Key results are presented which are being obtained with the world's highest energy DIS experiments performed at HERA. Prospects are discussed for the future of DIS and experimentation with electron–proton beams approaching the TeV scale of energy in the next decade(s).     

Active Separation of Water Isotopologues by Local Molecular Motion in Microporous Framework Materials

Around 10–15 % of the world's energy consumption is accounted for by the separation and purification of chemicals. Among them is the enrichment and separation of isotopologues which are an essential aspect of modern chemistry. In their recent work, Su et al. demonstrate the separation of water isotopologues by responsive dynamic pore windows in a microporous coordination polymer with unprecedented selectivity based on an elegant mechanism.     

The Role of Birth Control in the Survival of the Human Race

Analysis of the growth of the world's population shows that if no trenchant measures are taken, the number of the earth's inhabitants is likely to double to 8 billion people within as few as 35 years. Hormonal contraception is presently the best method available which would be capable of counteracting this trend. 6.5 tons of estrogen and 32 tons of progestogen would in theory be sufficient to protect the 500 million women of child-bearing age from unwanted pregnancies for one year.—In addition, the history, industrial methods of synthesis, mode of action and side effects of steroid contraceptives as well as the possible future developments are briefly mentioned.     

Nuclear Energy Reserves and Long-Term Energy Requirements

In this article the world's potential energy reserves are summarized on the basis of available estimates, and the future energy consumption is estimated with the aid of a working hypothesis relating to the growth of the world's population (P) and the energy consumption per capita (γ). According to this estimate, the energy requirements in 30 years will be about seven times and in 80 years about fifty times as high as they are today, and all the concentrated energy sources will be exhausted in about 120 to 160 years. – The energy requirements in the steady state (P_γ = const.) could be of the order of 10¹³ MWh per year and could be met out of magmatic rocks (U,Th) and sea water (U,D). High priority should be given to research and development work on the construction, reliability, and safety of breeder and fusion reactors, the chemical treatment and final disposal of radioactive waste, the extraction of uranium, thorium, and deuterium from the “primitive” raw materials, the relevant problems relating to protection of the environment, and the worldwide control of the excess birthrate.     

Application of Modern Analytical Techniques to the Investigation of Cellulose Nitrates

Abstract

Despite contemporary inroads made into the textile market by synthetic fibers, cellulose remains one of the world's most important textile materials. This can be rationalized in terms of several factors, the most important of which is the ready availability and continuing supply of this naturally occurring fiber. It has been estimated that vegetation produces about 100 billion tons of cellulose a year [1], and it is partly due to this fact that cellulose has maintained its position and competitive price in world markets.     

Effects of the shutdown of a nuclear fuel reprocessing plant on nearby streams

In a study conducted in 1971, levels of tritium were found in Cattaraugus-Creek, a stream in Western New York State. This material was attributed to the operation in West Valley, New York of the world's first commercial nuclear fuels reprocessing plant. Several fission fragment isotopes in addition to tritium were also observed in Buttermilk Creek, one of the tributaries of Cattaraugus Creek that runs through the reprocessing plant grounds. The plant ceased processing nuclear fuel in December 1971, and a new set of measurements in these streams were made to assess the effect of the ending of the plant's operation. Substantially lower concentrations of tritium and no fission produced isotopes have been observed.     

Kurt Gottlob – ein Leben für den Kautschuk

The chemist Kurt Gottlob (1881–1925) was one of the best‐known rubber technologists of the early 20th century. Kurt Gottlob's contributions were covering nearly all areas of rubber chemistry. Kurt Gottlob was one of the most important and creative members of the team around Fritz Hofmann (1866–1956) at Farbenfabriken, vorm. Friedr. Bayer, which developed methyl rubber, the world's first synthetic rubber. Together with Fritz Hofmann he discovered the organic accelerators, which revolutionized the vulcanization process of rubber. With his polymerization of isoprene in the presence of aqueous colloidal solutions of albumin he applied the principle of emulsion polymerization for the first time.     

Understanding the Physicoelectrochemical Properties of Carbon Nanotubes: Current State of the Art

Carbon nanotubes receive considerable attention in the area of electrochemistry not only due to their reported structural, mechanical or electronic properties but because they represent the world's smallest electrodes allowing electrochemistry to be performed where other electrode materials cannot penetrate. In this review, we overview recent developments in this area summarizing the fundamental advances in understanding the various factors and parameters that can significantly affect the electrochemical reactivity of carbon nanotubes, which is essential for their continual use and successful implementation in a plethora of areas and applications.     

Preparation of Ionic Liquid‐based Vilsmier Reagent from Novel Multi‐purpose Dimethyl Formamide‐like Ionic Liquid and Its Application

In continuation of research to explore the applied potential of DMF‐like ionic liquid, the ionic liquid version of N,N‐dimethyliminiumchloride (Vilsmier reagent) has been synthesized from DMF‐like ionic liquid and tested effectively for its capacity to achieve more useful organic transformations. The results show that DMF‐like ionic liquid is world's first task specific ionic liquid which has catalyzed numerous diverse type of reaction and is multipurpose in its application. Thus a new term for this DMF‐like ionic liquid has been coined that is DMF‐like "multipurpose" ionic liquid.     

A large scale virtual screen of DprE1

Tuberculosis continues to plague the world with the World Health Organization estimating that about one third of the world's population is infected. Due to the emergence of MDR and XDR strains of TB, the need for novel therapeutics has become increasing urgent. Herein we report the results of a virtual screen of 4.1 million compounds against a promising drug target, DrpE1. The virtual compounds were obtained from the Zinc docking site and screened using the molecular docking program, AutoDock Vina. The computational hits have led to the identification of several promising lead compounds.     

Chemistry must respond to the crisis of transgression of planetary boundaries

Recent assessments alarmingly indicate that many of the world''s leading chemicals are transgressing one or more of the nine planetary boundaries, which define safe operating spaces within which humanity can continue to develop and thrive for generations to come. The unfolding crisis cannot be ignored and there is a once-in-a-century opportunity for chemistry – the science of transformation of matter – to make a critical difference to the future of people and planet. How can chemists contribute to meeting these challenges and restore stability and strengthen resilience to the planetary system that humanity needs for its survival? To respond to the wake-up call, three crucial steps are outlined: (1) urgently working to understand the nature of the looming threats, from a chemistry perspective; (2) harnessing the ingenuity and innovation that are central to the practice of chemistry to develop sustainable solutions; and (3) transforming chemistry itself, in education, research and industry, to re-position it as ‘chemistry for sustainability’ and lead the stewardship of the world''s chemical resources. This will require conservation of material stocks in forms that remain available for use, through attention to circularity, as well as strengthening engagement in systems-based approaches to designing chemistry research and processes informed by convergent working with many other disciplines.

Chemistry, the science of transformation of matter, is fundamental to achieving sustainability through ensuring biogeochemical flows do not transgress planetary boundaries. This requires urgent changes in chemistry education, research and industry.     

Calcium Carbonate Dissolution from the Laboratory to the Ocean: Kinetics and Mechanism

The ultimate fate, over the course of millennia, of nearly all of the carbon dioxide formed by humankind is for it to react with calcium carbonate in the world's oceans. Although, this reaction is of global relevance, aspects of the calcite dissolution reaction remain poorly described with apparent contradictions present throughout the expansive literature. In this perspective we aim to evidence how a lack of appreciation of the role of mass-transport may have hampered developments in this area. These insights have important implications for both idealised experiments performed under laboratory conditions and for the measurement and modelling of oceanic calcite sediment dissolution.     

Selective Enzymatic Oxidation of Silanes to Silanols

Compared to the biological world's rich chemistry for functionalizing carbon, enzymatic transformations of the heavier homologue silicon are rare. We report that a wild‐type cytochrome P450 monooxygenase (P450_BM3 from Bacillus megaterium, CYP102A1) has promiscuous activity for oxidation of hydrosilanes to give silanols. Directed evolution was applied to enhance this non‐native activity and create a highly efficient catalyst for selective silane oxidation under mild conditions with oxygen as the terminal oxidant. The evolved enzyme leaves C?H bonds present in the silane substrates untouched, and this biotransformation does not lead to disiloxane formation, a common problem in silanol syntheses. Computational studies reveal that catalysis proceeds through hydrogen atom abstraction followed by radical rebound, as observed in the native C?H hydroxylation mechanism of the P450 enzyme. This enzymatic silane oxidation extends nature's impressive catalytic repertoire.     

Selective Enzymatic Oxidation of Silanes to Silanols

Compared to the biological world's rich chemistry for functionalizing carbon, enzymatic transformations of the heavier homologue silicon are rare. We report that a wild-type cytochrome P450 monooxygenase (P450_BM3 from Bacillus megaterium, CYP102A1) has promiscuous activity for oxidation of hydrosilanes to give silanols. Directed evolution was applied to enhance this non-native activity and create a highly efficient catalyst for selective silane oxidation under mild conditions with oxygen as the terminal oxidant. The evolved enzyme leaves C−H bonds present in the silane substrates untouched, and this biotransformation does not lead to disiloxane formation, a common problem in silanol syntheses. Computational studies reveal that catalysis proceeds through hydrogen atom abstraction followed by radical rebound, as observed in the native C−H hydroxylation mechanism of the P450 enzyme. This enzymatic silane oxidation extends nature's impressive catalytic repertoire.     

Cellulose Nanocomposites

Cellulose is a linear polysaccharide and one of the world's most abundant biopolymers. It is one of the renewable biopolymers being studied to reduce the dependence on non-renewable mineral oil based products. Cellulose can be used in different kinds of composites, including the recent nanocomposites.The production of nanoscale cellulose fibers and their use in polymer composites gained increasing attention due to their interesting properties and potential applications. This review paper is trying to cover studies done to use various forms of cellulose as reinforcement for different polymers, as matrix, as reinforcement and matrix for the same nanocomposite and as a component in polyblend nanocomposites beside other polymers.     

Authenticity study of commercial samples of St. John's wort by paper spray ionization mass spectrometry and chemometric tools

Hypericum perforatum L. (St. John's wort) is one of the world's most consumed medicinal plants for treating depression and psychiatric disorders. Counterfeiting can occur in the medicinal plant trade, either due to the lack of active ingredients or the addition of substances not mentioned on the labels, often without therapeutic value or even harmful to health. Hence, 43 samples of St. John's wort commercially acquired in different Brazilian regions and other countries were analyzed by paper spray ionization mass spectrometry (PS-MS) and modeled by principal component analysis. Hence, samples (plants, capsules, and tablets) were extracted with ethanol in a solid–liquid extraction. For the first time, PS-MS analysis allowed the detection of counterfeit H. perforatum samples containing active principles typical of other plants, such as Ageratum conyzoides and Senna spectabilis. About 52.3% of the samples were considered adulterated for having at least one of these two species in their composition. Furthermore, out of 35 samples produced in Brazil, only 13 were deemed authentic, having only H. perforatum. Therefore, there is a clear need to improve these drugs' quality control in Brazil.     

Reinforcing Poly(ethylene) with Cellulose Nanocrystals

The fabrication of nanocomposites of low‐density polyethylene (LDPE), one of the world's most widely used polymers, and cellulose nanocrystals (CNCs), which represent the world's most abundant bio‐based nanofiller, is reported. While the hydrophobic polymer and the hydrophilic filler seem to be intrinsically incompatible, this article shows that it is possible to kinetically trap homogeneous nanocomposites by a templating approach. An organogel is first prepared by exchanging the solvent of an aqueous CNC dispersion against acetone, impregnating the resulting organogel, in which the CNCs form a percolating network with a hot LDPE solution in toluene, and compression‐molding the resulting materials into thin films. At a filler content of 7.6% v/v, the resulting materials display a three‐ to four‐fold increase in strength and stiffness compared with the neat LDPE, which confirms that the CNC network could be largely maintained. It is also possible to reprocess these nanocomposites and dilute them with LDPE using conventional melt‐processing techniques.