Hasil untuk "Chemical industries"

J. Kumirska, M. Czerwicka, Z. Kaczyński et al.

Chitin, the second most important natural polymer in the world, and its N-deacetylated derivative chitosan, have been identified as versatile biopolymers for a broad range of applications in medicine, agriculture and the food industry. Two of the main reasons for this are firstly the unique chemical, physicochemical and biological properties of chitin and chitosan, and secondly the unlimited supply of raw materials for their production. These polymers exhibit widely differing physicochemical properties depending on the chitin source and the conditions of chitosan production. The presence of reactive functional groups as well as the polysaccharide nature of these biopolymers enables them to undergo diverse chemical modifications. A complete chemical and physicochemical characterization of chitin, chitosan and their derivatives is not possible without using spectroscopic techniques. This review focuses on the application of spectroscopic methods for the structural analysis of these compounds.

K. Savjani, A. Gajjar, J. Savjani

Solubility, the phenomenon of dissolution of solute in solvent to give a homogenous system, is one of the important parameters to achieve desired concentration of drug in systemic circulation for desired (anticipated) pharmacological response. Low aqueous solubility is the major problem encountered with formulation development of new chemical entities as well as for the generic development. More than 40% NCEs (new chemical entities) developed in pharmaceutical industry are practically insoluble in water. Solubility is a major challenge for formulation scientist. Any drug to be absorbed must be present in the form of solution at the site of absorption. Various techniques are used for the enhancement of the solubility of poorly soluble drugs which include physical and chemical modifications of drug and other methods like particle size reduction, crystal engineering, salt formation, solid dispersion, use of surfactant, complexation, and so forth. Selection of solubility improving method depends on drug property, site of absorption, and required dosage form characteristics.

S. Lee, J. Park, S. Jang et al.

V. Mourya, N. Inamdar

J. Hatch

M. Breuer, K. Ditrich, T. Habicher et al.

V. Khandegar, A. Saroha

K. Paździor, Lucyna Bilińska, S. Ledakowicz

Abstract The textile industry is known as releasing huge amounts of wastewater contaminated by a large spectrum of chemicals. There are several units (e.g. printers, mercerizing machines, finishing machines, dyers) within a dye house that generate different types of effluents, some of which (mostly dyers) work in batch mode. As a result, the wastewater composition varies significantly in concentration and time. Due to this, textile wastewater treatment can be very complicated. The recent trend in the textile industry is on-site wastewater treatment and the process water recycling. This review paper presents the recent developments in Advanced Oxidation Processes (AOPs), biological processes and their combinations for industrial textile wastewater. Most studies only investigated the mixed wastewater originating from the plants, without a deeper consideration on the effluents generated by different units within the dye house. Due to an extreme variation of the textile wastewater quality, the strategy of the division of the wastewater into separated streams according to their biodegradability is highly recommended. Particular attention has been paid in this review to the comparison of cost effectiveness of wastewater treatment processes. The presented considerations are based not only on a literature survey of the last 20 years but also on exemplified industrial cases of the application of AOPs and biological process in textile factories in Poland.

Aziz Fihri, C. Len, R. Varma et al.

T. Noël, Yiran Cao, G. Laudadio

Conspectus In the past decade, research into continuous-flow chemistry has gained a lot of traction among researchers in both academia and industry. Especially, microreactors have received a plethora of attention due to the increased mass and heat transfer characteristics, the possibility to increase process safety, and the potential to implement automation protocols and process analytical technology. Taking advantage of these aspects, chemists and chemical engineers have capitalized on expanding the chemical space available to synthetic organic chemists using this technology. Electrochemistry has recently witnessed a renaissance in research interests as it provides chemists unique and tunable synthetic opportunities to carry out redox chemistry using electrons as traceless reagents, thus effectively avoiding the use of hazardous and toxic reductants and oxidants. The popularity of electrochemistry stems also from the potential to harvest sustainable electricity, derived from solar and wind energy. Hence, the electrification of the chemical industry offers an opportunity to locally produce commodity chemicals, effectively reducing inefficiencies with regard to transportation and storage of hazardous chemicals. The combination of flow technology and electrochemistry provides practitioners with great control over the reaction conditions, effectively improving the reproducibility of electrochemistry. However, carrying out electrochemical reactions in flow is more complicated than just pumping the chemicals through a narrow-gap electrolytic cell. Understanding the engineering principles behind the observations can help researchers to exploit the full potential of the technology. Thus, the prime objective of this Account is to provide readers with an overview of the underlying engineering aspects which are associated with continuous-flow electrochemistry. This includes a discussion of relevant mass and heat transport phenomena encountered in electrochemical flow reactors. Next, we discuss the possibility to integrate several reaction steps in a single streamlined process and the potential to carry out challenging multiphase electrochemical transformations in flow. Due to the high control over mass and heat transfer, electrochemical reactions can be carried out with great precision and reproducibility which provide opportunities to enhance and tune the reaction selectivity. Finally, we detail on the scale-up potential of flow electrochemistry and the importance of small interelectrode gaps on pilot and industrial-scale electrochemical processes. Each principle has been illustrated with a relevant organic synthetic example. In general, we have aimed to describe the underlying engineering principles in simple words and with a minimum of equations to attract and engage readers from both a synthetic organic chemistry and a chemical engineering background. Hence, we anticipate that this Account will serve as a useful guide through the fascinating world of flow electrochemistry.

Shrabana Sarkar, A. Banerjee, Urmi Halder et al.

Michael L. Barnett

P. Pescarmona

Abstract Cyclic carbonates are a class of versatile compounds that can be prepared using the greenhouse gas carbon dioxide as building block and that can find applications as green solvents and as sustainable alternative to toxic reactants currently employed in the chemical industry. The current trends in research related to cyclic carbonates are reviewed in this contribution.

L. Candish, Karl D. Collins, G. Cook et al.

In the pursuit of new pharmaceuticals and agrochemicals, chemists in the life science industry require access to mild and robust synthetic methodologies to systematically modify chemical structures, explore novel chemical space, and enable efficient synthesis. In this context, photocatalysis has emerged as a powerful technology for the synthesis of complex and often highly functionalized molecules. This Review aims to summarize the published contributions to the field from the life science industry, including research from industrial-academic partnerships. An overview of the synthetic methodologies developed and strategic applications in chemical synthesis, including peptide functionalization, isotope labeling, and both DNA-encoded and traditional library synthesis, is provided, along with a summary of the state-of-the-art in photoreactor technology and the effective upscaling of photocatalytic reactions.

Richard Caron, Ravi A. Patel, Andreas Bogner et al.

This study focuses on a multiscale characterization of basic creep behavior of two AAS creep mixes with high (hS) and low (lS) slag content, loaded at 28 days. Nano-indentation tests are performed to investigate creep properties of individual phases and classical creep tests to analyze the creep behavior of concrete. An analytical multiscale micromechanics-based model is applied to downscale creep properties of the reaction product foam at nano-scale to compare it with results from nano-indentation. The creep at nanoscale of reaction product foam is modeled with a compliance function considering only deviatoric component consisting of Kelvin–Voigt chain for short term behavior and logarithmic function to account for long-term behavior. Comparing downscaled compliance with creep modulus measured from nano-indentation it is concluded that nano-indentation captures long-term behavior of reaction product foam. In terms of two mix tested, while at nano-scale mix hS has a higher creep modulus, presence of more capillary porosity and micro-cracks counteracts this and as a result concrete with mix hS shows higher creep. The creep modulus of AAS product foam obtained from nano-indentation is significantly lower compared to the OPC products. Additionally, higher amount of gel water and fewer crystalline secondary products could explain higher creep observed for AAS concrete compared to OPC concrete.

Doi Nguyen, Amporn Sae-Eaw, Penkwan Chompreeda et al.

The synergistic effects of cinnamon and oregano essential oils (EOs) against Staphylococcus aureus, Bacillus cereus, and Aspergillus flavus were evaluated by using a disc volatilization assay. Minimum inhibitory concentration (MIC) was indicated at 5 μL L−1 air when the ratios of cinnamon and oregano EOs were 8:2 and 9:1 (v/v) for all tested bacteria, which also showed strongly synergistic activities (fractional inhibition concentration index (FIC) ≤ 0.48). However, there was only the combination ratio 6:4 showing a synergistic effect on the inhibition of A. flavus. Therefore, this combination was selected for incorporating with cassava starch films according to the central composite design. Desirability function approach indicated the optimal film formulation was 45.54 % of sorbitol and 0.65 % of EOs. The tensile strength and elongation at break of the optimal film were 8 MPa and 27 %, respectively while the AM film showed 100 % inhibition for all tested microorganisms. In the artificial contamination test, the antimicrobial film could express the inhibition at 85 % and 100 % on the growth of A. flavus in artificially and naturally contaminated Vietnamese bread, respectively.

Norma Angélica Bolivar-Jacobo, Raúl Alberto Reyes-Villagrana, Martha María Arévalos-Sánchez et al.

Postbiotics are recently gaining consumer attention for their potential health benefits. This study aimed to examine the effects of supplementation of a non-fermented dairy beverage with postbiotics derived from <i>Lactobacillus acidophilus</i> and <i>Lactobacillus helveticus</i> on antioxidant (DPPH, ABTS, FRAP, and ORAC), antimicrobial, and ACE-inhibition activities before and after in vitro digestion. Three dairy beverages were elaborated: without the addition of postbiotics (T0), with <i>Lactobacillus acidophilus</i> postbiotics (T1), and with <i>Lactobacillus helveticus</i> postbiotics (T2). Before in vitro digestion, T2 presented higher antioxidant activity (<i>p</i> < 0.05). And, after in vitro digestion, except by the ABTS method, T1 and T2 presented the highest antioxidant activities (<i>p</i> < 0.05) and bioaccessibility indexes (<i>p</i> < 0.05). Regarding ACE-inhibition activity, before in vitro digestion, there were no differences among treatments (<i>p</i> > 0.05), but after in vitro digestion, T1 and T2 presented the highest ACE-inhibition activities (<i>p</i> < 0.05) and bioaccessibility indexes (<i>p</i> < 0.05). An antimicrobial effect against <i>Bacillus</i> spp. and <i>S. aureus</i> was observed in <i>Lactobacillus acidophilus</i> and <i>Lactobacillus helveticus</i> postbiotics. However, <i>L. acidophilus</i> postbiotics did not present an antibacterial effect against <i>E. coli</i>. Such findings highlight the potential of postbiotics as functional ingredients to enhance the antioxidant and ACE-inhibition activities of non-fermented dairy beverages, further adding to their appeal as health-promoting dairy food.

Mekala Venkatachalam

There has been a continuous increase in consumer awareness regarding the availability of natural, sustainable, biodegradable options in all sectors, including food, cosmetics, pharmaceuticals, textiles, painting, printing inks, etc [...]

J. Kinsella, D. M. Whitehead

Farah Elgudayem, Abdullah Aldiyab, Marzough Aziz Albalawi et al.

PurposeThe Polygonum equisetifome is a prospective plant source of high protein, unsaturated fatty acids, and useful safe bioactive molecules. Therefore, the aim of this study was to optimize the ultrasonic aqueous extraction of phenols from P. equisetifome roots using Box-Behnken design based statistical modeling, and to evaluate the antioxidant and antibacterial efficiencies of P. equisetifome root extracts against pathogenic bacteria.MethodsIn this study, the box-behnken design was used to optimize the extraction of phenols. The extraction temperature (30–70°C), ultrasound assisted extraction (UAE) time (1–9 min), and liquid-solid ratio (35–45 mL/g) were investigated as the factors that influence the phenolic yield (Y1) and their DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activity (Y2).ResultsThe optimal conditions for both responses were 50°C, 5 min, and 40 mL/g. At these conditions, Y1 reached its maximum to be 45.321 mg GAE/g dry weight and Y2 to be 120.354 μmol Trolox/g dry weight. The P. equisetifome roots contained water soluble phenol, high anthocyanin, and condensed tannins. Interestingly, the P. equisetifome extracts showed a relation to its antioxidant and antibacterial activities, FRAP (Ferric-reducing/antioxidant power), and ABTS scavenging activity were determined. The morphological and physico-chemical features of the extract were analyzed using SEM-EDX, FT-IR, and minimum inhibitory concentration (MIC) was analyzed against several pathogenic bacteria. The antibacterial activity of the extract showed that the extract is more efficient against Staphylococcus aureus, while the P. equisetifome extracts showed efficient MIC against S. aureus, followed by Bacillus cereus.SuggestionsThe relation of P. equisetifome extracts to its antioxidant, and antibacterial efficiencies open a new avenue of their potential uses in the food and pharmaceutical industries.