Effect of additives on the critical micelle concentration of some polyethoxylated nonionic detergents

The effect of electrolytes and other additives influencing water structure, viz., urea and formamide, has been studied on the micelle formation of polyethoxylated nonionic detergents in their aqueous solutions. The decrease in critical micelle concentration (c.m.c.) by electrolytes has been interpreted in terms of salting out mechanism and evidence has been obtained in support of the contention that micelles of polyethoxylated nonionic detergents are weakly positively charged. Effect of urea and formamide on the c.m.c. values of these nonionic detergents indicate that hydrophobic bonding is loosened in their presence with a consequent increase in the c.m.c. of these detergents.     

Carbonate and phosphate detergent builders: Their impact on the environment

The impact of detergent builders on the environment is critically examined by review of the literature, material balance calculations, wastewater treatment experiments and aquatic toxicity studies. The experiments were designed to assess the influence of alkalinity and carbonates on various sewage treatment processes. Carbonate detergent builders were found to have no detrimental effect on sewage treatment. There was no indication that carbonate detergents are more toxic to fish than phosphate detergents. Presented at the AOCS Meeting, Atlantic City, October 1971.     

Mixtures of soap and a commercial alkyl aryl sulfonate

Summary This middle ground between the soaps and synthetics has not been actively exploited in spite of the intense current interest in the straight products. It has been a no man's land where the manufacturers of synthetic detergents have carefully avoided soap, which they regard as outside of their field, while many manufacturers of soap have been indifferent to the effect of the synthetic detergents. In spite of this general indifference work has been done on both sides of the fence with a continually increasing use of the mixtures. Where mixtures have been ready-made, the soap manufacturers have been largely responsible for their manufacture. Commercial mixtures of soaps and synthetics have been sold where synthetic detergents have been found to improve soap for specific uses. This trend is certain to expand. The present success should encourage further research and development commensurate with the increasing commercial importance of the products. Presented at the annual fall meeting, American Oil Chemists' Society, Oct. 31, Nov. 1–3, 1949, Chicago, Ill.     

Anticancer activity of natural and synthetic acetylenic lipids

This review is a comprehensive survey of acetylenic lipids and their derivatives, obtained from living organisms, that have anticancer activity. Acetylenic metabolites belong to a class of molecules containing triple bond(s). They are found in plants, fungi, microorganisms, and marine invertebrates. Although acetylenes are common as components of terrestrial plants, fungi, and bacteria, it is only within the last 30 years that biologically active polyacetylenes having unusual structural features have been reported from plants, cyanobacteria, algae, invertebrates, and other sources. Naturally occurring aquatic acetylenes are of particular interest since many of them display important biological activities and possess antitumor, antibacterial, antimicrobial, antifouling, antifungal, pesticidal, phototoxic, HIV-inhibitory, and immunosuppressive properties. There is no doubt that they are of great interest, especially for the medicinal and/or pharmaceutical industries. This review presents structures and describes cytotoxic and anticancer activities only for more than 300 acetylenic lipids and their derivatives isolated from living organisms.     

Oxidation Catalysis by Rationally Designed Artificial Metalloenzymes

The principle of enzyme mimics has been raised to its pinnacle by the design of hybrids made from inorganic complexes embedded into biomolecules. The present review focuses on the design of artificial metalloenzymes for oxidation reactions by oxygen transfer reactions, with a special focus on proteins anchoring inorganic complexes or metal ions via supramolecular interactions. Such reactions are of great interest for the organic synthesis of building blocks. In the first part, following an overview of the different design of artificial enzymes, the review presents contributions to the rational design of efficient hybrid biocatalysts via supramolecular host/guest approaches, based on the nature of the inorganic complex and the nature of the protein, with special attention to the substrate binding. In the second part, the original purpose of artificial metalloenzymes has been twisted to enable the observation of transient intermediates, to decipher metal-based oxidation mechanisms. The host protein crystals have been used as crystalline molecular-scale vessels, within which inorganic catalytic reactions have been followed, thanks to X-ray crystallography. These hybrids should be an alternative to enzymes for sustainable chemistry.     

Zeolite based films, membranes and membrane reactors: Progress and prospects

The integration of reaction and separation in catalytic membrane reactors has received increasing attention during the past 30 years. The combination promises to deliver more compact and less capital-intensive processes with substantial savings in energy consumption. With the advent of new inorganic materials and processing techniques, there has been renewed interest in exploiting the benefits of membranes in many industrial applications. Zeolite membranes, however, have only recently been considered for catalytic membrane reactor applications. Despite the significant recent interest in these types of membranes there are relatively few reports of the application of such membranes in high-temperature catalytic membrane reactor applications. This can be attributed to a number of limitations that still need to be addressed such as the relatively high price of membrane units, the difficulty of controlling the membrane thickness, permeance, high-temperature sealing, reproducibility and the dilemma of upscaling. A number of research efforts, with some degree of success have been directed to finding solutions to the remaining challenges. This review makes a critical assessment of what has been achieved in the past few years in terms of hurdles that still stand in the way of the successful implementation of zeolite membrane reactors in industry.     

Physiological Effects of Neonicotinoid Insecticides on Non-Target Aquatic Animals—An Updated Review

In this paper, we review the effects of large-scale neonicotinoid contaminations in the aquatic environment on non-target aquatic invertebrate and vertebrate species. These aquatic species are the fauna widely exposed to environmental changes and chemical accumulation in bodies of water. Neonicotinoids are insecticides that target the nicotinic type acetylcholine receptors (nAChRs) in the central nervous systems (CNS) and are considered selective neurotoxins for insects. However, studies on their physiologic impacts and interactions with non-target species are limited. In researches dedicated to exploring physiologic and toxic outcomes of neonicotinoids, studies relating to the effects on vertebrate species represent a minority case compared to invertebrate species. For aquatic species, the known effects of neonicotinoids are described in the level of organismal, behavioral, genetic and physiologic toxicities. Toxicological studies were reported based on the environment of bodies of water, temperature, salinity and several other factors. There exists a knowledge gap on the relationship between toxicity outcomes to regulatory risk valuation. It has been a general observation among studies that neonicotinoid insecticides demonstrate significant toxicity to an extensive variety of invertebrates. Comprehensive analysis of data points to a generalization that field-realistic and laboratory exposures could result in different or non-comparable results in some cases. Aquatic invertebrates perform important roles in balancing a healthy ecosystem, thus rapid screening strategies are necessary to verify physiologic and toxicological impacts. So far, much of the studies describing field tests on non-target species are inadequate and in many cases, obsolete. Considering the current literature, this review addresses important information gaps relating to the impacts of neonicotinoids on the environment and spring forward policies, avoiding adverse biological and ecological effects on a range of non-target aquatic species which might further impair the whole of the aquatic ecological web.     

An Overview on the Synthetic Routes and Properties of Ammonium Dinitramide (ADN) and other Dinitramide Salts

In recent years, there has been a considerable interest in the development of novel type of high performance propellants for use in solid rocket motors. Ammonium salt of dinitramidic acid NH₄N(NO₂)₂ (ADN) has attracted wide interest as a potentially useful energetic oxidizer for rocket propellants because of its clean and environment‐friendly exhaust products during burning. ADN contains one N (NO₂)₂ group and its synthesis requires new type of N‐nitration. The present paper reviews the general synthetic methods used for the synthesis of inorganic, organic and metal dinitramide salts and their properties, with a special emphasis on ammonium dinitramide. The salient features with reference to the extent of conversion and ease of separation of the products of the various synthetic methodologies are also addressed.     

Bacterial Bio-Resources for Remediation of Hexachlorocyclohexane

In the last few decades, highly toxic organic compounds like the organochlorine pesticide (OP) hexachlorocyclohexane (HCH) have been released into the environment. All HCH isomers are acutely toxic to mammals. Although nowadays its use is restricted or completely banned in most countries, it continues posing serious environmental and health concerns. Since HCH toxicity is well known, it is imperative to develop methods to remove it from the environment. Bioremediation technologies, which use microorganisms and/or plants to degrade toxic contaminants, have become the focus of interest. Microorganisms play a significant role in the transformation and degradation of xenobiotic compounds. Many Gram-negative bacteria have been reported to have metabolic abilities to attack HCH. For instance, several Sphingomonas strains have been reported to degrade the pesticide. On the other hand, among Gram-positive microorganisms, actinobacteria have a great potential for biodegradation of organic and inorganic toxic compounds. This review compiles and updates the information available on bacterial removal of HCH, particularly by Streptomyces strains, a prolific genus of actinobacteria. A brief account on the persistence and deleterious effects of these pollutant chemical is also given.     

A mini-review and recent outlooks on the synthesis and applications of zeolite imidazolate framework-8 (ZIF-8) membranes on polymeric substrate

Zeolite imidazolate framework (ZIF) is one of the subclasses of metal–organic frameworks (MOFs) that has been widely investigated in the last decade. Among the ZIF members, a particular interest has been devoted to ZIF-8 due to various factors, such as mild and fast synthesis conditions, framework stability and the right pore aperture to perform various separations. Recently, there has also been growing interest in developing ZIF-8 as a thin layer membrane on polymeric substrates as they are considerably cheaper than the inorganic ones. This review then discusses recent advances in this field, focusing on various fabrication strategies and promising future applications. The challenges and future perspectives are also discussed with an emphasis on employing this approach in industrial scale. © 2020 Society of Chemical Industry     

Extracellular Vesicles from Plants: Current Knowledge and Open Questions

The scientific interest in the beneficial properties of natural substances has been recognized for decades, as well as the growing attention in extracellular vesicles (EVs) released by different organisms, in particular from animal cells. However, there is increasing interest in the isolation and biological and functional characterization of these lipoproteic structures in the plant kingdom. Similar to animal vesicles, these plant-derived extracellular vesicles (PDEVs) exhibit a complex content of small RNAs, proteins, lipids, and other metabolites. This sophisticated composition enables PDEVs to be therapeutically attractive. In this review, we report and discuss current knowledge on PDEVs in terms of isolation, characterization of their content, biological properties, and potential use as drug delivery systems. In conclusion, we outline controversial issues on which the scientific community shall focus the attention shortly.     

Hybrid phosphazene-organosilicon polymers: II. High-polymer and materials synthesis and properties

Most of the polymers that have been synthesized and studied over the past 50 years are organic macromolecules. However, many advantages exist for the development of polymers with inorganic backbones. The first major class of inorganic backbone polymers to be developed widely were the polytorganosiloxanes] (silicones), and these now are the subject of broad industrial and fundamental interest. Polyphosphazenes are a relatively new class of inorganic backbone polymers which rival many organic systems in their molecular structural diversity and property variations. They constitute only the second group of inorganic-organic polymers to be developed extensively. An emerging field of research involves an attempt to create a new area of polymer science at the interface between these two subjects, by the synthesis of hybrid organophosphazene organosilicon systems. This review is a summary of recent progress in this new field.     

洗涤剂绿色化升级的机遇和挑战

基于绿色化学的核心和原则,阐述了绿色洗涤剂自身应具备的特点以及绿色洗涤剂与普通洗涤剂的区别。分析了中国主流消费群体的变化趋势以及消费者对洗涤剂产品的认知,表明新主流消费群体对洗涤剂产品关注度在持续提高,并且更加关注洗涤剂对人体和环境安全性的影响。主流消费群体关注度提高和行业标准法规的变化趋势必然会引导和推动洗涤行业向绿色健康的方向发展,然而绿色洗涤剂的发展仍然面临诸多挑战。     

The potential of pervaporation for biofuel recovery from fermentation:An energy consumption point of view

Recovering alcohols from dilute fermentation broth is an emergent task in bio-fuel production process. Since they are primary planned for fuels, energy required to separate these alcohols should be considered in evaluating the potential of a separation technology. A membrane-based process, pervaporation, is of special interest because of its environmental friendliness and easy integrating character. This review probes into the fundamentals of pervaporation especially in terms of the heat required for evaporation. Meanwhile, the separation data of the most representative alcohol-selective pervaporation membranes reported in the literatures are collected and compared with the vapor–liquid equilibrium curve, which represents the distillation selectivity. They include:inorganic membranes, silicon rubber based membranes, Mixed Matrix Membranes and some other special materials. By doing so, the status of alcohol recovery via pervaporation would be more clear for researchers.For ethanol recovery, it is selectivity rather than flux that is in urgent need of solution. While for butanol recovery,membranes with satisfactory selectivity have been developed, increasing the separation capacity would be more pressing.     

吸附分离水体中铀的吸附材料研究新进展

铀是最危险的放射性金属之一,广泛存在于核燃料的制备、乏燃料后处理和矿石开采等生产活动所产生的含铀废水中,严重威胁水生生态系统与人类健康。吸附法处理水中的U(Ⅵ)具有便捷高效、经济和选择性好的优势。综述了近3年对水中铀吸附材料的研究新进展,介绍了无机、有机、有机无机复合和生物衍生类吸附材料的制备,结构特点,吸附性能,并对铀吸附材料的研究方向进行了展望。     

Role of Chemical Mediators in Aquatic Interactions across the Prokaryote–Eukaryote Boundary

There is worldwide growing interest in the occurrence and diversity of metabolites used as chemical mediators in cross-kingdom interactions within aquatic systems. Bacteria produce metabolites to protect and influence the growth and life cycle of their eukaryotic hosts. In turn, the host provides a nutrient-enriched environment for the bacteria. Here, we discuss the role of waterborne chemical mediators that are responsible for such interactions in aquatic multi-partner systems, including algae or invertebrates and their associated bacteria. In particular, this review highlights recent advances in the chemical ecology of aquatic systems that support the overall ecological significance of signaling molecules across the prokaryote–eukaryote boundary (cross-kingdom interactions) for growth, development and morphogenesis of the host. We emphasize the value of establishing well-characterized model systems that provide the basis for the development of ecological principles that represent the natural lifestyle and dynamics of aquatic microbial communities and enable a better understanding of the consequences of environmental change and the most effective means of managing community interactions.     

Recent Development of Photothermal Agents (PTAs) Based on Small Organic Molecular Dyes

Photothermal therapy (PTT) has attracted great attention due to its noninvasive and effective use against cancer. Various photothermal agents (PTAs) including organic and inorganic PTAs have been developed in the last decades. Organic PTAs based on small-molecule dyes exhibit great potential for future clinical applications considering their good biocompatibility and easy chemical modification or functionalization. In this review, we discuss the recent progress of organic PTAs based on small-molecule dyes for enhanced PTT. We summarize the strategies to improve the light penetration of PTAs, methods to enhance their photothermal conversion efficiency, how to optimize PTAs’ delivery into deep tumors, and how to resist photobleaching under repeated laser irradiation. We hope that this review can rouse the interest of researchers in the field of PTAs based on small-molecule dyes and help them to fabricate next-generation PTAs for noninvasive cancer therapy.     

Role of non-functionalized oxide nanoparticles on mechanical properties and toughening mechanisms of epoxy nanocomposites

Over the past few decades, the use of epoxy resins has gained significant attention from worldwide researchers due to its advantages in structural applications in various sectors like automotive, construction, and aerospace industries. This article summarizes and reviews the research on mechanical properties and toughening mechanism of epoxy composites filled with non-functionalized oxide nanoparticles. The incorporation of nanomaterials into the polymer matrix has been considered to be the most effective route to improve the mechanical properties of polymer composites. But the inherent brittle nature and cross-linking ability of epoxy makes it vulnerable to crack initiation and crack growth and limits its use in advanced structural applications. Recently, various kinds of nanofillers such as carbon nanotubes (CNTs), organic and inorganic oxide nanoparticles have attracted industrial interest due to their excellent mechanical, thermal, and electrical properties which can provide a dramatic improvement in the properties of epoxy composites but their dispersion issue, agglomeration and bundling problems deteriorate several important mechanical parameters of the epoxy composites. To date, no review article focused on the role of non-functionalized oxide nanoparticles on the improvement in mechanical properties of the reinforced epoxy composites. This review article assesses and summarizes some most recent findings on the de-agglomeration process, mechanical properties, and toughening mechanisms of epoxy nanocomposites reinforced with four types of most preferred non-functionalized oxide nanoparticles such as Al₂O₃, TiO₂, SiO_2, and ZrO₂.     

橡胶材料硫磺硫化体系低锌/无锌技术研究进展

硫化是决定橡胶是否能够作为材料使用最为重要的步骤。橡胶硫磺硫化体系中,氧化锌的使用不仅可以改善橡胶的硫化性能,并且能够大幅度提高橡胶制品的物理机械性能。但是,由于游离的锌离子易迁移至环境,会对水生生物等产生危害,所以欧盟和美国加州相继颁布法案限制氧化锌的使用。另外,锌矿产资源也日渐枯竭。因此,减少锌元素在橡胶配方中的应用,是保护环境并保证橡胶硫化反应正常进行的热点研究课题。该综述介绍了目前橡胶硫磺硫化体系配方中减少硫化活化剂氧化锌的用量和用非含锌化合物替代氧化锌的研究进展,包括纳米氧化锌、有机锌复合物、无机填料载锌技术、其他金属氧化物和稀土型多功能橡胶硫化剂等新型硫化活化剂的研究现状,并对未来发展方向进行展望。     

The impact of biodegradable surfactants on water quality

The purpose of this paper is to review some of the recent contributions of the detergent industry to the national effort for cleaner water. Probably the single most important achievement to date has been the industry’s voluntary conversion from the use of alkyl benzene sulfonate (ABS) to linear alkylate sulfonate (LAS) and other biodegradable surfactants. This changeover was completed in mid-1965 at a cost that has been estimated to exceed $150,000,000. Since LAS was the surfactant of primary interest, the bulk of the pre- and postconversion research, in terms of water-pollution control, has been with that material. This paper concerns itself mainly with the over-all impact of the conversion to LAS on water quality. Data from pilot and full-scale sewage-treatment plants throughout the country are included, which clearly demonstrate the effectiveness of the conversion in terms of significantly lower surfactant residue levels.