Chemical Engineering Approach Research Articles

Chemical reaction engineering of nutritional phenomena in the human body

Unlike many accomplished fields, human nutrition lacks the support of engineering science. Here, the aspects of food processing in the gastro-intestinal (GI) tract are reviewed, highlighting the experimental chemical reaction engineering (CRE) approach to digestion studies in particular. As a first look at human nutrition in terms of conservation laws, the differential forms of mass and energy balances are presented, emphasizing the chemical and biochemical reaction rates of generation and consumption and the heats associated with these reactions, respectively. These rates and the heats should be very meaningful for understanding the dynamics of nutrition within the body, though they remain unknown. Without solving the differential equations, global integrations of the mass balances within each organ, up to the organ boundary, can create control volumes for gaining new insights, such as the transient multicomponent nature of the stomach “reactor” emptying. Global integration within the human body to the boundaries of the entire GI tract, from the mouth to anus, finds the GI tract to be a “pipe outside the body.” This has revealed interesting aspects, highlighting the human body as a “molecular machine.” It is envisaged that the terms outlined here ought to be established in the future to improve human nutrition.

A Scalable and Robust Water Management Strategy for PEMFCs: Operando Electrothermal Mapping and Neutron Imaging Study.

Effective water management is crucial for the optimal operation of low-temperature polymer electrolyte membrane fuel cells (PEMFCs). Excessive liquid water production can cause flooding in the gas diffusion electrodes and flow channels, limiting mass transfer and reducing PEMFC performance. To tackle this issue, a nature-inspired chemical engineering (NICE) approach has been adopted that takes cues from the integument structure of desert-dwelling lizards for passive water transport. By incorporating engraved, capillary microchannels into conventional flow fields, PEMFC performance improves significantly, including a 15% increase in maximum power density for a 25 cm2 cell and 13% for a 100 cm2 cell. Electro-thermal maps of the lizard-inspired flow field demonstrate a more uniform spatial distribution of current density and temperature than the conventional design. Neutron radiography provides evidence that capillary microchannels in the lizard-inspired flow field facilitate the efficient transport and removal of generated liquid water, thereby preventing blockages in the reactant channels. These findings present a universally applicable and highly efficient water management strategy for PEMFCs, with the potential for widespread practical implementation for other electrochemical devices.

Strategies to Diversification of the Mechanical Properties of Organic Crystals

AbstractStructurally ordered soft materials that respond to complementary stimuli are susceptible to control over their spatial and temporal morphostructural configurations by intersectional or combined effects such as gating, feedback, shape‐memory, or programming. In the absence of general and robust design and prediction strategies for their mechanical properties, at present, combined chemical and crystal engineering approaches could provide useful guidelines to identify effectors that determine both the magnitude and time of their response. Here, we capitalize on the purported ability of soft intermolecular interactions to instigate mechanical compliance by using halogenation to elicit both mechanical and photochemical activity of organic crystals. Starting from (E)‐1,4‐diphenylbut‐2‐ene‐1,4‐dione, whose crystals are brittle and photoinert, we use double and quadruple halogenation to introduce halogen‐bonded planes that become interfaces for molecular gliding, rendering the material mechanically and photochemically plastic. Fluorination diversifies the mechanical effects further, and crystals of the tetrafluoro derivative are not only elastic but also motile, displaying the rare photosalient effect.

Strategies to Diversification of the Mechanical Properties of Organic Crystals.

Structurally ordered soft materials that respond to complementary stimuli are susceptible to control over their spatial and temporal morphostructural configurations by intersectional or combined effects such as gating, feedback, shape-memory, or programming. In the absence of general and robust design and prediction strategies for their mechanical properties, at present, combined chemical and crystal engineering approaches could provide useful guidelines to identify effectors that determine both the magnitude and time of their response. Here, we capitalize on the purported ability of soft intermolecular interactions to instigate mechanical compliance by using halogenation to elicit both mechanical and photochemical activity of organic crystals. Starting from (E)-1,4-diphenylbut-2-ene-1,4-dione, whose crystals are brittle and photoinert, we use double and quadruple halogenation to introduce halogen-bonded planes that become interfaces for molecular gliding, rendering the material mechanically and photochemically plastic. Fluorination diversifies the mechanical effects further, and crystals of the tetrafluoro derivative are not only elastic but also motile, displaying the rare photosalient effect.

A nature-inspired solution for water management in flow fields for electrochemical devices

A nature-inspired solution for water management in flow fields for electrochemical devices.

Nanozymes as Catalytic Marvels for Biomedical and Environmental Concerns: A Chemical Engineering Approach

Nanozymes as Catalytic Marvels for Biomedical and Environmental Concerns: A Chemical Engineering Approach

Engineered exosomes for cancer theranostics: Next-generation tumor targeting

Exosomes are multivesicular bodies of which the plasma membrane fuse to release the caring moiety into the surrounding body fluids. They are best known for their function in mediating intercellular connectivity by transferring various biomolecules, such as proteins, RNAs, and lipids, from one cell to another. These “naturally equipped” nanovesicles could be therapeutically targeted or engineered as drug delivery systems. The use of exosomes in cancer detection and prognosis has attracted a great deal of interest from academics. In addition to chemical, biological, and genetic engineering approaches, other current exosomal alteration methodologies hold promise for the advancement of therapeutic medicines for cancer. In this review, we highlight the theranostic potential of exosomes for therapeutic delivery in various cancers.

Cascade utilization of crop straw through a FeCl3-mediated deep eutectic solvent biorefinery: Lignin-containing cellulose nanofibers flocculant fabrication followed by fertilizer production

The current agriculture relies heavily on the input of fossil resource-based chemicals while continuously generating crop straw residue and phosphorus-containing farmland drainage, which has been a serious threat to its sustainable development. This work proposed a closed-loop technique route to cascade utilization of crop straw residue through lignin-containing cellulose nanofibers (LCNFs) flocculant fabrication followed by fertilizer production, with the goal of farmland drainage phosphorus recovery and reuse. The technical feasibility of FeCl3-mediated deep eutectic solvents (DES) processing of wheat and rice straw into iron oxide immobilized LCNFs (Fe-LCNFs) flocculant, the flocculation performance of total phosphorus for representative farmland drainage, and the potential for co-production of glucose and phosphorus-containing fertilizer were comprehensively assessed. Results showed that the FeCl3 incorporation significantly enhanced the deconstruction and fractionation ability of DESs, resulting in nearly 100% hemicellulose removal and 86.4% delignification. The prepared Fe-LCNFs flocculant exhibited efficient total phosphorus removal of 99.9%. The spent flocs exhibited considerable glucose conversion of ∼52.4% even with iron oxide and phosphorus complex. It was calculated that 8.6 g reactive lignin, 27.9 g phosphorus-containing fertilizer and 30.7 g glucose additive for foliar fertilizer could be mostly obtained using this integrated technique. It was proposed that the dual function of biomass deconstruction and lignin fragmentation/relocation of the employed FeCl3-mediated DESs showed a determined role in enhancing the flocculation performance of Fe-LCNFs and enzymatic hydrolysis efficiency of the spent flocs. This work showed a chemical engineering approach for cascade and closed-loop utilization of crop straw toward more sustainable and green agriculture application.

Sodium oleate potentiates the concurrent overproduction of lipids and carotenoids in Chlorella vulgaris towards biofuel and nutraceutical applications

Microalgal metabolites have emerged as potential commodity components due to their notable beneficial nutritional and economic properties, and thus, their overproduction is of paramount importance to combat the existing ecological and dietary issues. However, the production titer of these metabolites by the algal systems at optimal cultivation conditions is inadequate to meet the burgeoning global demand for those metabolites. Therefore, a pressing demand remains to concurrently co-produce valuable metabolites without compromising cellular biomass production. Here, we report an effective strategy that simultaneously overproduces lipids, biomass and carotenoids in Chlorella vulgaris by providing sodium oleate (NaOL) in the cultivation medium. Supplement of sodium oleate at the optimal concentration (50 µg/mL) at increased light intensity enhances cellular growth rate in a dose-dependent manner. Total lipid content was quantified, which showed that lipid content was significantly increased in the NaOL-treated cells by 2.08-fold than that of the control cells. Interestingly, spectrophotometric determination of total carotenoids showed that carotenoid content was increased by 2.48-fold in the T5 (50 µg/mL) NaOL treated cells compared to the control. Interestingly antioxidant analysis showed that NaOL provision alleviated the antioxidant potential of the algal cells. Together, this report exemplifies the potential strategy to preclude the existing intricacies of co-producing metabolites in C. vulgaris by supplementing NaOL, thereby highlighting the viable chemical engineering approach for the biological production of commercially essential metabolites in microalgae.

An integrated chemical engineering approach to understanding microplastics

AbstractEnvironmental and health risks posed by microplastics (MPs) have spurred numerous studies to better understand MPs' properties and behavior. Yet, we still lack a comprehensive understanding due to MP's heterogeneity in properties and complexity of plastic property evolution during aging processes. There is an urgent need to thoroughly understand the properties and behavior of MPs as there is increasing evidence of MPs' adverse health and environmental effects. In this perspective, we propose an integrated chemical engineering approach to improve our understanding of MPs. The approach merges artificial intelligence, theoretical methods, and experimental techniques to integrate existing data into models of MPs, investigate unknown features of MPs, and identify future areas of research. The breadth of chemical engineering, which spans biological, computational, and materials sciences, makes it well‐suited to comprehensively characterize MPs. Ultimately, this perspective charts a path for cross‐disciplinary collaborative research in chemical engineering to address the issue of MP pollution.

HMSCs in contact with DMSO for cryopreservation: Experiments and modeling of osmotic injury and cytotoxic effect.

In this study a combined analysis of osmotic injury and cytotoxic effect useful for the optimization of the cryopreservation process of a cell suspension is carried out. The case of human Mesenchymal Stem Cells (hMSCs) from Umbilical Cord Blood (UCB) in contact with dimethyl sulfoxide (DMSO) acting as Cryo‐Protectant Agent (CPA) is investigated from the experimental as well as the theoretical perspective. The experimental runs are conducted by suspending the cells in hypertonic solutions of DMSO at varying osmolality, system temperature, and contact times; then, at room temperature, cells are pelleted by centrifugation and suspended back to isotonic conditions. Eventually, cell count and viability are measured by means of a Coulter counter and flow‐cytometer, respectively. Overall, a decrease in cell count and viability results when DMSO concentration, temperature, and contact time increase. A novel mathematical model is developed and proposed to interpret measured data by dividing the cell population between viable and nonviable cells. The decrease of cell count is ascribed exclusively to the osmotic injury caused by expansion lysis: excessive swelling causes the burst of both viable as well as nonviable cells. On the other hand, the reduction of cell viability is ascribed only to cytotoxicity which gradually transforms viable cells into nonviable ones. A chemical reaction engineering approach is adopted to describe the dynamics of both phenomena: by following the kinetics of two chemical reactions during cell osmosis inside a closed system it is shown that the simultaneous reduction of cell count and viability may be successfully interpreted. The use of the Surface Area Regulation (SAR) model recently proposed by the authors allows one to avoid the setting in advance of fixed cell Osmotic Tolerance Limits (OTLs), as traditionally done in cryopreservation literature to circumvent the mathematical simulation of osmotic injury. Comparisons between experimental data and theoretical simulations are provided: first, a nonlinear regression analysis is performed to evaluate unknown model parameters through a best‐fitting procedure carried out in a sequential fashion; then, the proposed model is validated by full predictions of system behavior measured at operating conditions different from those used during the best‐fit procedure.

Tin perovskite solar cells with >1,300h of operational stability in N2 through a synergistic chemical engineering approach.

SummaryDespite the promising properties of tin-based halide perovskites, one clear limitation is the fast Sn+2 oxidation. Consequently, the preparation of long-lasting devices remains challenging. Here, we report a chemical engineering approach, based on adding Dipropylammonium iodide (DipI) together with a well-known reducing agent, sodium borohydride (NaBH4), aimed at preventing the premature degradation of Sn-HPs. This strategy allows for obtaining efficiencies (PCE) above 10% with enhanced stability. The initial PCE remained unchanged upon 5 h in air (60% RH) at maximum-power-point (MPP). Remarkably, 96% of the initial PCE was kept after 1,300 h at MPP in N2. To the best of our knowledge, these are the highest reported values for Sn-based solar cells. Our findings demonstrate a beneficial synergistic effect when additives are incorporated, highlight the important role of iodide in the performance upon light soaking, and, ultimately, unveil the relevance of controlling the halide chemistry for future improvement of Sn-based perovskite devices.

Design of functional hydrogels using smart polymer based on elastin-like polypeptides

Elastin-like polypeptides (ELPs) are genetically encoded materials that enable the bottom-up design and manufacture of functional biomaterials. Here, we report the design and synthesis of a lysine-rich ELPs modified with methacrylate groups, giving rise to temperature-induced phase transition and photo-crosslinking capabilities. The degree of methacrylate functionalization could be varied by changing the reactant ratio of N-succinimidyl methacrylate (NHS-MA) to ELPs. The prediction of the structural transition with increasing temperature was validated using integrated experimental and simulation approaches. Combined with hydrogel fabrication strategy, methacrylated ELPs (ELP-MA) can be engineered into different physical forms like coacervates and hydrogels, which further function as light transmittance regulator and elastic adhesives. In addition, physical properties of the hydrogels such as mechanical strength, pore size, and swelling ratio could be controlled by the methacrylation degree and ELP-MA concentration. Subcutaneous implantation in mice showed that the resulting ELP-MA hydrogels exhibited a good biocompatibility. Our biological and chemical engineering approaches to creat functional materials of the ELP-MA will be useful to design various smart materials in the future.

Gene Cluster Analysis of Marine Bacteria Seeking for Natural Anticancer Products

Background: In the past decade, metabolites of marine microorganisms have been increasingly used for their various biological activities. An intense effort has been dedicated to assessing the therapeutic efficacy of the marine natural products and metabolites obtained from marine bacteria in cancer therapy. Fast and reliable analytical bacterial genome sequencing provides specialized bioinformatic tools to identify potential gene clusters in bacteria for obtaining secondary metabolites. Objectives: This study aimed to analyze the genome sequences of marine bacteria to recognize bioactive compounds with anti-cancer properties. Methods: Marine bacteria with the genomic sequences registered in the National Center for Biotechnology Information (NCBI) genome database were used in this study. The genome was analyzed for proteins, tRNAs, and rRNAs from GenBank entries by Feature Extract 1.2L Server. The Anti-SMASH webserver was used for the analysis of unique marine bacterial metabolites of the marine bacterial genome, available from the NCBI database. Results: A number of marine bacterial species, including Salinispora arenicola, Salinispora tropica, Crocosphaera watsonii, and Blastopirellula marina encoded metabolites belonging to the polyketide and nonribosomal peptide (NRP) families, showing anti-cancer properties. Among the marine species described, S. tropica and S. arenicola are richer in the genes encoding polyketide and NRP with potential antitumor activities. Conclusions: Marine bacteria are an excellent and exceptional source of anti-cancer compounds. In silico genome analysis of marine bacteria provided an opportunity to evaluate gene clusters for known natural products. Like this chemical engineering approaches for pharmaceutical application are useful in clinical evaluation of cancer treatment.

Detection and toxicity modeling of anthraquinone dyes and chlorinated side products from a colored smoke pyrotechnic reaction

“Green” pyrotechnics seek to remove known environmental pollutants and health hazards from their formulations. This chemical engineering approach often focuses on maintaining performance effects upon replacement of objectionable ingredients, yet neglects the chemical products formed by the exothermic reaction. In this work, milligram quantities of a lab-scale pyrotechnic red smoke composition were functioned within a thermal probe for product identification by pyrolysis-gas chromatography-mass spectrometry. Thermally decomposed ingredients and new side product derivatives were identified at lower relative abundances to the intact organic dye (as the engineered sublimation product). Side products included chlorination of the organic dye donated by the chlorate oxidizer. Machine learning quantitative structure-activity relationship models computed impacts to health and environmental hazards. High to very high toxicities were predicted for inhalation, mutagenicity, developmental, and endocrine disruption for common military pyrotechnic dyes and their analogous chlorinated side products. These results underscore the need to revise objectives of “green” pyrotechnic engineering.

An Overview of the Sorption Studies of Contaminants on Poly(Ethylene Terephthalate) Microplastics in the Marine Environment

Marine pollution is one of the biggest environmental problems, mainly due to single-use or disposable plastic waste fragmenting into microplastics (MPs) and nanoplastics (NPs) and entering oceans from the coasts together with human-made MPs. A rapidly growing worry concerning environmental and human safety has stimulated research interest in the potential risks induced by the chemicals associated with MPs/NPs. In this framework, the present review analyzes the recent advances in adsorption and desorption studies of different contaminants species, both organic and metallic, on MPs made of Poly(Ethylene terephthalate). The choice of PET is motivated by its great diffusion among plastic items and, unfortunately, also in marine plastic pollution. Due to the ubiquitous presence of PET MPS/NPs, the interest in its role as a vector of contaminants has abruptly increased in the last three years, as demonstrated by the very high number of recent papers on sorption studies in different environments. The present review relies on a chemical engineering approach aimed at providing a deeper overview of both the sorption mechanisms of organic and metal contaminants to PET MPs/NPs and the most used adsorption kinetic models to predict the mass transfer process from the liquid phase to the solid adsorbent.

The development in biological wastewater treatment over the last 50 years.

The paper summarizes the development in the understanding and practical application of the activated sludge process over the last 50 years. Since its invention, the activated sludge process has been a big challenge to design engineers. Traditionally, the technology was covered by sanitary engineers. However, with the development in the understanding of activated sludge process principles, further progress was not possible without knowledge of reaction kinetics and reactor theory. The shift from BOD removal only to combined removal of organic pollution, nitrogen and phosphorus required a chemical engineering approach with outputs of activated sludge microbiology and microbial ecology. Molecular biology enabled more accurate identification of important activated sludge microorganisms. The development in activated sludge process also required more efficient activated sludge separation and thickening. The paper describes the development from secondary clarifiers to membrane separation. Increasing water stress around the globe has also changed the main wastewater paradigm from wastewater treatment and safe discharge to safe reuse.

Taking Advantage of the Morpheein Behavior of Peroxiredoxin in Bionanotechnology.

Morpheeins are proteins that reversibly assemble into different oligomers, whose architectures are governed by conformational changes of the subunits. This property could be utilized in bionanotechnology where the building of nanometric and new high-ordered structures is required. By capitalizing on the adaptability of morpheeins to create patterned structures and exploiting their inborn affinity toward inorganic and living matter, “bottom-up” creation of nanostructures could be achieved using a single protein building block, which may be useful as such or as scaffolds for more complex materials. Peroxiredoxins represent the paradigm of a morpheein that can be applied to bionanotechnology. This review describes the structural and functional transitions that peroxiredoxins undergo to form high-order oligomers, e.g., rings, tubes, particles, and catenanes, and reports on the chemical and genetic engineering approaches to employ them in the generation of responsive nanostructures and nanodevices. The usefulness of the morpheeins’ behavior is emphasized, supporting their use in future applications.

How chemical boundary engineering can produce cheap, ultra-strong steels

An innovative chemical boundary engineering approach can produce ultra-high strength steel at much lower cost. Ran Ding, Zhigang Yang, Sybrand van der Zwaag and Hao Chen at Tsinghua University in China say strengths up to 2300 MPa are possible.

Development of a mechanistic model of leaf surface gas exchange coupling mass and energy balances for life-support systems applications

Growing plants in space during long-duration missions will be crucial to ensure functions such as food production, air revitalization, and water purification, and requires an in-depth understanding of plant growth and development processes in reduced gravity. In particular, gas exchange at the leaf surface is considerably reduced because of lack or reduction of buoyancy-driven convection, which can translate into reduced biomass production in the long run. To quantify this impaired gas exchange and biomass production, this study formulates a mechanistic model of these variables in low gravity following a chemical engineering approach. The emphasis here is set on short-term physical response of gas exchange at the leaf surface to gravity and airspeed. A mass balance with stoichiometric limitations enables the computation of mass exchange fluxes, and an energy balance relates them to heat transfer fluxes. Leaf surface temperature and biomass production in the form of dry mass and free water mass are then subsequently computed. The validation of this model on sets of independent data from published parabolic flight experiments is presented and a sensitivity study to different parameters highlights the existence of threshold values for gravity, ventilation, light, and stomatal conductance, which dictate the magnitude of changes in leaf surface temperature and photosynthesis rate. These results show that a mechanistic modeling approach coupled to a dedicated experimental approach are key to identify adequate growth conditions for plants in reduced gravity environments.