Philosophy Of Green Chemistry Research Articles

Highly efficient degradation of antibiotic residues with reagent-free photoelectro-fenton via hollow fiber gas diffusion electrode

Fenton advanced oxidation technology is a potential treatment option for emerging organic pollutants in wastewaters. The challenges in the effective activation and generation of H2O2 limit its practical applications. We designed a chemical reagent-free Photoelectric-Fenton (PEF) system. Using an electro-chemical oxygen reduction reaction (ORR) employing Cu hollow fiber gas diffusion electrodes (Cu-hf-GDE) H2O2 was generated and was subsequently converted to OH using Fe/CN thin film on batch wall reactors. This PEF system demonstrated efficient elimination of florfenicol at a concentration of 10 ppm. The study revealed that O2− were the key species for the electrical generation of H2O2, while OH were the dominant reactive oxygen species (ROSs) for florfenicol degradation. A mechanism for the degradation of florfenicol was proposed, and the ecotoxicity of florfenicol and its degradation intermediates was investigated. The reusability, stability, and application potential of the PEF system in real water bodies were also assessed. Overall, this work demonstrates an example of pollution control resulting from philosophy of green chemistry, which offers a promising pathway to reduce the chemical demand for advanced oxidation processes.

Sustainable and feasible reagent-free electro-Fenton via sequential dual-cathode electrocatalysis

Electro-Fenton processes aim at producing oxidizing radicals with fewer added chemicals and residues but are still unable to completely eliminate both. This study demonstrates that a reagent-free electro-Fenton process that runs solely on oxygen and electricity can be achieved by sequential dual-cathode electrocatalysis. H2O2 is produced on an electrodeposited PEDOT on carbon cloth (PEDOT/CC) cathode and subsequently converted to hydroxyl radicals on a stainless-steel-mesh cathode. The dual-cathode system demonstrates efficient decolorization and total organic carbon (TOC) removal toward organic dyes at optimized cathodic potentials of -0.9 V for PEDOT/CC and -0.8 V for the stainless-steel mesh. The sequential dual-cathode process also displays high reusability, no iron leaching, high removal efficiency using air instead of oxygen, and low installation and operation costs. This work demonstrates a preeminent and commercially viable example of pollution control rendered by the "catalysis instead of chemical reagent" philosophy of green chemistry.

Deep Eutectic Solvents as an Alternate to Other Harmful Solvents

Solvents generally in liquid form, are used to dissolve, dilute, suspend any substances or extract other materials. More than one-third of the drugs listed in the various Pharmacopeias fall into the poorly water-soluble or water-insoluble categories. For more than 200 years, traditional solvents could be used as a solvent for substances that were insoluble in water. But the usage of these types of solvents should be decreased because these types of solvents are volatile, flammable, and often toxic. Also, the industrialist’s usages in different types of processes prove the risk for workers. In recent years, several solvents have been proposed to be the greener replacement for traditional solvents. Replacing hazardous chemicals with more environmentally friendly alternatives is a matter of current interest, in line with the philosophy of Green Chemistry. The use of nontraditional or nonconventional solvents such as supercritical fluids (SCFs) such as Carbon dioxide (CO2) and water, fluorous solvents, solventless reaction Ionic liquids (ILs) and their derivatives [polymeric ILs and magnetic ILs], and deep eutectic solvents (DESs) are alternatives for environmentally unfriendly traditional solvents. Among them, DES is a neoteric class of green solvents defined as a mixture of two or more compounds that are typically solid at room temperature, but when combined at a particular molar ratio, changes into a liquid at room temperature. It is assumed that eutectic mixtures show low volatility, have a broad liquid range, and are water-compatible, non-flammable, non-toxic, biocompatible, and eco-friendly. Eutectic solvents have been useful in several pharmaceutical fields, such as the increase of drug solubility, permeation, and absorption.

Sol-gel technology for greener and more sustainable antimicrobial textiles that use silica matrices with C, and Ag and ZnO as biocides

Based on the philosophy of Green Chemistry, in order to grant antimicrobial properties to fabrics, in this work a 100% cotton fabric was used impregnating silver (Ag) and zinc oxide (ZnO) with the addition of carbon extracted from disused batteries, in the intuition of reuse them in a conscious and relevant way. For this, a simple and greener chemical route that occurs at low temperatures was used, the silica-based sol-gel method, which requires a precursor, in this case, tetraethyl orthosilicate (TEOS), and a catalyst to generate the basic hydrolysis using ammonium hydroxide. To evaluate the durability of the coating on the fabric, it was subjected to several wash cycles. Finally, its antimicrobial activity against fungal and bacterial strains was evaluated by the modified standard method (DIN 53931) and the agar-based diffusion method (SN 195920–1992), respectively. The sol-gel green method was effective for obtaining coating for the inhibition of fungal and bacterial strains. In addition, there was a high degree of persistence of the additives after the washing cycles before the antimicrobial tests, registering inhibition up to 20 cycles, making not only the process but also the final alternative fabric greener and more sustainable.

Green Synthesis up to Geometric Gold Microparticles

In this work the study of optical properties of micro and nanostructured particles of gold is approached. A method of nanoparticle stabilization synthesis based on the philosophy of green chemistry by using orange extract (Citrus X sinensis) was proposed. Controlling specific parameters of the proposed synthesis method, particles with sizes lower than 50 nm were obtained and after the heat treatment the geometric particle sizes ranged from 0.2 to 2 μm. The optical absorption of the particles was studied finding absorption bands associated with the surface plasmon resonance. Experimentally, the nanomaterials obtained were tested on pyridine as SERS substrate. Complementary, in order to find clues of vibrational behavior, theoretically the interaction with pyridine molecule and gold layer structure were considered. The individual systems were perturbed by incident radiation with blue (435 nm), green (532 nm), red (638 nm) and infrared (785 nm and 1064) wavelengths for its SERS analysis.

Green Chemistry: Some important forerunners and current issues

In this essay some important forerunners of green chemistry will be discussed and compared with the present state. The relationship to ethics will be considered. Starting from the new movement of green chemistry by Anastas, some important highlights will be presented. The new activities of IUPAC and other institutions on the concepts of metrics for green syntheses will be discussed. The prime importance of the inclusion of developing African countries into the concepts will also be covered. Green chemistry philosophy has become part of sustainable chemistry which emphasizes the implementation of the concept of sustainability in the production and use of chemicals and chemical products for sustainable development and, some sustainable development concepts are included under the section on Africa.

Química Verde nos cursos de Licenciatura em Química do Brasil: mapeamento e importância na prática docente

A filosofia da Química Verde ou Química Sustentável tem como sua definição a criação, desenvolvimento e aplicação de produtos e processos químicos a fim de reduzir e eliminar o uso e a geração de substâncias nocivas. Um curso de licenciatura em química visa formar profissionais que atuarão diretamente na formação de pessoas conscientes, reflexivas, cidadãs através do espaço escolar. O uso das filosofias da Química Verde nas aulas desses futuros profissionais, são de extrema importância. O objetivo deste trabalho foi obter dados do cenário da educação em Química Verde nos cursos de Licenciatura em Química ofertados nas instituições públicas de ensino superior do país.

Effect of Evening Primrose Oil-Based Polyol on the Properties of Rigid Polyurethane⁻Polyisocyanurate Foams for Thermal Insulation.

The article presents the results of research on the synthesis of a new biopolyol based on evening primrose oil, and its use in the production of rigid polyurethane–polyisocyanurate foams intended for thermal insulation. The obtained biopolyol was subjected to analytical, physicochemical, and spectroscopic tests (Fourier transform infrared (FTIR), 1H NMR, 13C NMR) to confirm its suitability for the synthesis of polyurethane materials. Then, it was used for the partial replacement of the petrochemical polyol in the polyurethane formulation. Obtained rigid polyurethane–polyisocyanurate foams are characterized by a lower apparent density, brittleness, water absorption, and thermal conductivity coefficient λ. In addition, foams modified by biopolyols had a higher content of closed cells and higher aging resistance. The results of the conducted research showed that the use of the biopolyol based on evening primrose oil may be an alternative to petrochemical polyols. The research presented herein is perfectly consistent with the trends of sustainable development and the philosophy of green chemistry.

Metal–organic frameworks as a new platform for molecular oxygen and aerobic oxidation of organic substrates: Recent advances

Since metal–organic frameworks (MOFs) as a novel kind of crystalline porous materials containing metal ions and organic linkers have emerged in the early 1990s, the number of publications associated with MOFs have remarkably grown in various fields including synthesis methods, structure analysis, gas storage, separation, drug delivery and catalysis. In this review, we outline the recent progress in the application of MOFs as heterogeneous catalysts for oxidations, focusing on the processes that have used the molecular oxygen or air as an oxidant. These two types of oxidants comply with the philosophy of green chemistry and thus provide the greener method concerning environmental benignity and sustainability. Also, the tandem oxidation processes (TOP) which are catalyzed in a manner mentioned above and their proposed mechanisms are presented in detail.

The Philosophy of Green Chemistry as Applied to the Microscale Inorganic Chemistry Laboratory

<span>The advantages of using microscale chemistry in the laboratory are well known, especially in the area of Organic Chemistry (Mayo et al., 1994). These include lower experiment costs, reduced exposure to potentially toxic materials, shorter reaction times, smaller waste disposal costs, and lower construction costs. These benefits are strongly applicable to the inorganic chemistry laboratory, where high chemical costs, toxicity issues and long reaction times often combine to ensure that many interesting experiments cannot be performed at all.</span>

Organo-catalytic [4+2] Aza Diels Alder Cycloaddition Reaction in an Environmentally Benign Solvent System

Green chemistry brings an attention on a research work emerging from scientific innovations regarding toxic waste acquaintance and it make the use of principles that reduces the use or generation of hazardous materials in an intermediate as well as final steps of Organic synthesis or Chemical progression. Researchers can significantly diminish the hazard to human health as well as environment by following all the valuable philosophy of green chemistry. The most simple way in application of green chemistry in pharmaceuticals is to use efficient, reproducible, eco-friendly, non-hazardous green solvents and green catalysts in synthesis of Organic Moiety, drug intermediates and in researches concerning synthetic chemistry. Organic catalyst brings an exceptional advantage considering the principles of “green chemistry” in Environment as well as economic point of view. Solvents states major serving of the environmental concert of a process and also impact safety and health issues. Water has been found to be very efficient green Solvent and thus can replace many poisonous and harmful solvents. Cycloaddition reactions are fundamental and substantial part of organic chemistry in research. Research work on the aza Diels alder cycloaddition reactions in aqueous systems would be green pathway for organic processes and will definitely protect health as well as environment from toxic materials.

Incorporating Sustainability in Higher Chemistry Education in Indonesia through Green Chemistry: Inspirations by Inquiring the Practice in a German University

Green chemistry is suggested as an important guide to allow the practice of chemistry to become more sustainable. In this study, a chemistry department at a German university is analyzed by an outside view to how it integrates the philosophy of green chemistry into its research and teaching practices to inform higher education institutions in Indonesia on how this issue could be approached. The study reveals that the level of understanding of green chemistry is largely varying among different stakeholders, however its principles are well integrated in both research and teaching. In addition, it became clear that today modern chemistry departments should operate a broader approach towards sustainability than just practicing green chemistry in laboratory practices. The vision is to highlight the importance of green chemistry and other corresponding practices to support education for sustainable development (ESD) in a broad sense. The integration of green chemistry to support the implementation of ESD in higher education can only be achieved by strong commitments from all groups involved, namely the head and administration of the department, researchers, and teachers. Although not all aspects that were observed during this study are suitable to be applied in the Indonesian context, some implications can be derived for reform in Indonesian higher chemistry education.

A STATISTICAL APPROACH FOR OPTIMIZING THE HIGH YIELD GREEN PRODUCTION OF THE FLAVOR ESTER BUTYL BUTYRATE

Being the prevailing approach for producing esters such as butyl butyrate, the use of chemical route has been linked to numerous disadvantages. Hence, a green alternative method for higher yield production of butyl butyrate by esterification reaction utilizing Novozyme 435 as biocatalysts in a solvent-less system may prove useful. Such approach can be further improved by optimizing the relevant reaction parameters using the Response Surface Methodology by the Box-Benkhen Design attempted in this present study. The reaction parameters evaluated were: substrate molar ratio, time and temperature, and the response of each parameter was measured as percentage conversion yield. Using the Design Expert 7.1.6 optimization functions, the two sets of optimum conditions selected viz. [i] molar ratio butyric acid:butanol 1:3.93, 9.93 h at 56.09°C and [ii] molar ratio butyric acid:butanol 1:3.35, 9.79 h at 53.90°C had afforded the highest yield of butyl butyrate i.e. 99.62% and 99.55%, respectively. The ester product obtained from the reaction were confirmed as butyl butyrate by FTIR and GC. Therefore, the results substantiated the applicability of the RSM prediction technique as well as efficacy of Novozyme 435 as biocatalysts in the high yield solvent-less synthesis of butyl butyrate, adhering to the philosophy of Green Chemistry.

Towards Eco-reflexive Science Education

The modern world can be described as a globalized risk society. It is characterized by increasing complexity, unpredictable consequences of techno-scientific innovations and production, and its environmental consequences. Therefore, chemistry, just like many other knowledge areas, is in an ongoing process of environmentalization. For example, green chemistry has emerged as a new chemical metadiscipline and movement. The philosophy of green chemistry was originally based on a suggestion of twelve principles for environment-friendly chemistry research and production. The present article problematizes limitations in green chemistry when it comes to education. It argues that the philosophy of green chemistry in the context of education needs to be extended with socio-critical perspectives to form educated professionals and citizens who are able to understand the complexity of the world, to make value-based decisions, and to become able to engage more thoroughly in democratic decision-making on sustainability issues. Different versions of sustainability-oriented science/chemistry education are discussed to sharpen a focus on the most complex type, which is Bildung-oriented, focusing emancipation and leading to eco-reflexive education. The term eco-reflexive is used for a problematizing stance towards the modern risk society, an understanding of the complexity of life and society and their interactions, and a responsibility for individual and collective actions towards socio-ecojustice and global sustainability. The philosophical foundation and characteristics of eco-reflexive science education are sketched on in the article.

ChemInform Abstract: Multicomponent Reactions: Advanced Tools for Sustainable Organic Synthesis

AbstractReview: 129 refs.

Sequential injection technique as a tool for the automatic synthesis of silver nanoparticles in a greener way

This paper presents a new way to the synthesis of uniform and size-controlled silver nanoparticles by means of microreaction technology. It complies with the philosophy of green chemistry by developing a process that prevents pollution at source—by automation of the manipulations using microtubes manifolds and with the use of benign reagents and photochemistry to enhance the reaction of synthesis of Ag nanoparticles. Effect of hydrodynamic parameters (reagent volumes and volume flow rate) and concentrations (reducer and stabilizer), temperature, pH and UV irradiation time on morphology and size of nanoparticles was studied. The silver nanoparticles has been characterized by transmission electronic microscopy (TEM), electron diffraction X-ray spectroscopy (EDS), UV–vis spectra analysis, dynamic light scattering (DLS) and zeta potential measurements. Particles are mostly spherical in shape and have average sizes between 7 and 20nm. The particle size can be controlled by changing not only the flow rate and UV light time exposition but also the reducer/AgNO3 concentration ratio.This is a sustainable and cost-saving methodology that guarantees not only reproducible synthesis, but also the changing of NPs characteristics at time by simple control of the fluid transport.

Green chemistry in Brazil

The philosophy of green chemistry has been very well received in Latin America’s research and development programs. In this review we describe the green chemistry contributions of Brazilian research groups over the last three years.

ChemInform Abstract: The Case for the Use of Unrefined Natural Reagents in Analytical Chemistry: A Green Chemical Perspective

AbstractReview: 86 refs.

Green Chemistry: Cresting a Summit toward Sustainability

As chemistry evolves, priorities must be identified and incorporated to guide chemists toward a sustainable future. When applied, the 12 principles of Green Chemistry deliver both environmental and economic benefit and logically should be adopted in every industrial and academic chemistry endeavour. In the main, this has not happened. While Green Chemistry philosophy has been generally accepted by the scientific community, technical Green Chemistry evolution through education, investment, and exemplification has yet to achieve the appropriate attention and effort. Three critical opportunities exist that can be used to redress this state of affairs and provide the necessary Green Chemistry evolution: improving engagement and support of business and academic leaders, enhancing education and technical guidance, and evolving toward proactive and pragmatic regulatory policies. Seizing these opportunities is an imperative start toward cresting a Green Chemistry summit that descends toward ultimate sustainability.

Green Chemistry: Principles and Practice

Green Chemistry is a relatively new emerging field that strives to work at the molecular level to achieve sustainability. The field has received widespread interest in the past decade due to its ability to harness chemical innovation to meet environmental and economic goals simultaneously. Green Chemistry has a framework of a cohesive set of Twelve Principles, which have been systematically surveyed in this critical review. This article covers the concepts of design and the scientific philosophy of Green Chemistry with a set of illustrative examples. Future trends in Green Chemistry are discussed with the challenge of using the Principles as a cohesive design system (93 references).