Methods for determining solute rejection in organic solvent nanofiltration (OSN) are time-consuming and expensive and still rely on wet-lab measurements, resulting in the slow development of membrane ...processes. OSN, similar to other membrane technologies, requires precise and comprehensive predictive models that can function on various solutes, membranes, and solvents. We present two prediction methods based on the quantitative structure–activity relationship (QSAR) using traditional machine learning (ML) and deep learning (DL) models. The partial least-squares regression model combined with the variable importance in projection and genetic algorithm achieves a slightly lower root-mean-square error score (8.04) than the DL-based graph neural network (10.40). For the first time, we visualize the effect of different solute functional groups on rejection, providing a new platform for a more in-depth investigation into the membrane–solute interactions, potentially enabling the design of membranes with improved selectivity. Our ML model is freely accessible on the OSN database website (www.osndatabase.com) for everyone.
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•Feature-based QSAR machine learning solute rejection prediction.•The first application and exploration of Deep Learning in OSN.•Structure-based precise solute rejection prediction in organic solvent nanofiltration.•Visualization of rejection-altering features and functional groups.•First online prediction tool for organic solvent nanofiltration (www.osndatabase.com).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
As a result of recent efforts in green solvent selection, methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate, sold under the brand name Rhodiasolv PolarClean, has received considerable scientific and ...industrial attention as a possible non-toxic replacement for common polar aprotic solvents. However, the multicomponent nature and multi-step synthesis of this solvent remains an obstacle for its more widespread use and niche applications. In this work, a retrosynthetic approach was taken to identify novel shorter synthetic routes in alignment with green chemistry principles. High purity methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate was obtained in novel single-step reactions
via
two different base-catalysed Michael additions from readily available building blocks. The more advanced synthetic route shows great potential owing to the swift (30 min), solvent-free reaction and catalytic amounts of base (<6.5 mol%). Green metrics analysis, including Atom Economy, Complete
E
factor, Carbon Intensity and hazard analysis found the new synthesis to be more sustainable than the patented routes. Application of this green solvent was demonstrated for the first time for
O
- and
N
-arylation in S
N
Ar reaction with solvent recovery with similar or superior yields compared to other green solvents. Moreover, broad opportunities for this green solvent in membrane science were identified, where the use of conventional, toxic polar aprotic solvents in large quantities is unavoidable. Important practical solvent properties and parameters such as dielectric constant, solubility parameters, solvent miscibility and NMR residual shifts have been determined to facilitate the uptake of methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate as a green solvent.
Greener synthetic routes, physical-chemical properties, green metrics performance and applications for the eco-friendly polar aprotic solvent, methyl 5-dimethylamino-2-methyl-5-oxopentanoate (PolarClean).
Materials discovery is rapidly revolutionizing all aspects of our lives. However, the design and fabrication of materials are often unsustainable and resource-intensive. Hence, we need a paradigm ...shift towards designing sustainable materials
in silico
. Machine learning, a subfield of artificial intelligence (AI), is emerging within the sustainability agenda because it promises to benefit science and engineering through improved quality, performance, and predictive power. Here we present a new methodology to extend the application of AI to develop materials in an environmentally friendly way. We demonstrate successful materials development by combining design of experiments with a new machine learning module that comprises a support vector machine, an evolutionary algorithm, and a desirability function. We use our AI-based method to realize the sustainable electrochemical synthesis of a ZIF-8 metal-organic framework and explore the hyperdimensional relationship between the synthesis parameters, product qualities, and process sustainability. The presented AI-based methodology paves the way for solving the challenge of the materials fabrication-sustainability nexus, and facilitates the paradigm shift from the wet lab to the wired lab.
Artificial intelligence in combination with design of experiments for sustainable process development achieving high quality metal-organic frameworks (MOFs) with minimal environmental effect.
Membrane separations are considered to be sustainable technologies because of their relatively low energy consumption. However, the fabrication of membranes is yet to turn green. Thin film composite ...(TFC) membranes are fabricated from petroleum-based monomers and solvent systems, which can undermine the energy-saving benefits of their application in separation processes. Here, we report high-performance TFC membranes fabricated solely from sustainable resources such as plant-based monomers (priamine, tannic acid), green solvents (
p
-Cymene, water) and recycled polymer waste (PET). We found that the ultrathin selective layer (30 nm) of the hydrophobic membrane exhibited excellent performance, and an acetone permeance as high as 13.7 L m
−2
h
−1
bar
−1
with a 90% rejection of styrene dimer (235 g mol
−1
). Stability in six solvents and long-term continuous nanofiltration over one week demonstrated the robustness of the membranes. Control over the selectivity of the membrane (cut-off between 236 and 795 g mol
−1
) was successfully achieved by changing the conditions of the interfacial polymerization.
High-performance and solvent-resistant TFC membranes fabricated solely from sustainable resources such as plant-based monomers, green solvents and recycled polymer waste.
Covalent organic frameworks (COFs) have attracted considerable interest owing to their structural predesign ability, controllable chemistry, long-range periodicity, and pore interior ...functionalization ability. The most widely adopted solvothermal synthesis of COFs requires the use of toxic organic solvents. In line with the 5
th
principle of green chemistry and the United Nations' 12
th
Sustainable Development Goal, we aim to mitigate the adverse effect of solvents on COF synthesis. Here we have investigated twelve green solvents for the sustainable synthesis of five series of COFs using the solvothermal approach. Crystallinity and porosity were used to assess the quality of the obtained COFs. In addition, the suitability of the solvents in the synthesis of crystalline and porous COFs was investigated and color-coded for the final green assessment. In particular, γ-butyrolactone (for
TpPa
,
TpBD
, and
TpAzo
),
para
-cymene (
TpAnq
), and PolarClean (
TpTab
) were found to be excellent green solvents to produce high-quality COFs. For the first time, we successfully used quantitative structure-property relationships in combination with machine learning approaches to predict both the surface area and crystallinity of COFs using the structure of the solvents and COF building blocks.
Covalent organic frameworks have been prepared in sustainable solvents by a solvothermal method, and their porosity and crystallinity were predicted using QSPR and machine learning approaches.
The electrospinning of high-performance polyimides (PI) has recently sparked great interest. In this study, we explore the effect of the electrospinning parameters — namely polymer concentration, ...voltage, tip-to-collector distance and flow rate — and salt addition on the diameter, morphology, and spinnability of electrospun PI nanofibers. Three different polyimides of intrinsic microporosity (PIM-PIs) with high Brunauer–Emmett–Teller (BET) ranging from 270 to 506 m2 g−1, and two microporous polyimides, were synthesized through the polycondensation of 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and aromatic diamines. The addition of tetraethylammonium bromide (TEAB) salt considerably increased the conductivity of all the PI solutions, significantly improved spinability, and resulted in thinner fibers. We also used molecular dynamic simulations to investigate the macromolecular mechanism of improved spinnability and fiber morphology in the presence of an ammonium salt. The small droplets detached from the parent droplet, followed by the rapid evaporation of the ions through the hydration effect, which facilitated the electrospinning. The resulting uniform nanofibers have great potential in environmental applications due to the presence of microporosity and hydrophobic pendant trifluoromethyl groups, which enhance the sorption performance of the fibers for hydrophobic species.
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•Five different microporous polyimides having pendant trifluoromethyl groups were synthesized through polycondensation.•Uniform nanofibers were produced at low polymer concentrations due to improved spinnability in the presence of a salt.•Higher salt content drastically increased the solution conductivity and led to thinner electrospun fibers.•A higher flow rate increased fiber diameter due to the higher mass flow.•Molecular dynamics simulations demonstrated faster solvent evaporation in the presence of salt.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Organic solvent nanofiltration (OSN) is an energy-efficient separation technique that has the potential to improve environmental sustainability in many industrial sectors, including food processing, ...biorefineries, and in the production of pharmaceuticals, fine chemicals and petrochemicals. Some issues, however, hinder the pace of development of this sustainable separation method that could ultimately provide green manufacturing strategies. These issues include lack of clear experimental designs, explicit experimental protocols, comparable performance data and long-term performance tests of membranes at industrially relevant solute concentrations in OSN studies. Here, we report on a survey of the OSN research community and on a critical assessment of 177 journal papers published from 2015 to 2019 to determine how the scientific value and industrial impact of OSN studies can be improved. Based on the results of our survey and literature analysis, we crafted a series of best-practice recommendations for researchers reporting data on membrane fabrication, membrane materials characterization and filtration performance, process integration and fundamental studies.
The way forward to improve and standardize membrane reports, and to bridge the gap between academic efforts and industrial requirements.
The catalytic transformation of bio‐derived compounds, specifically 5‐hydroxymethylfurfural (HMF), into value‐added chemicals may provide sustainable alternatives to crude oil and natural gas‐based ...products. HMF can be obtained from fructose and successfully converted to 2,5‐diformylfuran (DFF) by an environmentally friendly organic electrosynthesis performed in an ElectraSyn reactor, using cost‐effective and sustainable graphite (anode) and stainless‐steel (cathode) electrodes in an undivided cell, eliminating the need for conventional precious metal electrodes. In this work, the electrocatalysis of HMF is performed by using green solvents such as acetonitrile, γ‐valerolactone, as well as PolarClean, which is used in electrocatalysis for the first time. The reaction parameters and the synergistic effects of the TEMPO catalyst and 2,6‐lutidine base are explored both experimentally and through computation modeling. The molecular design and synthesis of a size‐enlarged C3‐symmetric tris‐TEMPO catalyst are also performed to facilitate a sustainable reaction work‐up through nanofiltration. The obtained performance is then compared with those obtained by heterogeneous TEMPO alternatives recovered by using an external magnetic field and microfiltration. Results show that this new method of electrocatalytic oxidation of HMF to DFF can be achieved with excellent selectivity, good yield, and excellent catalyst recovery.
Up the tempo: An efficient TEMPO‐based electrocatalytic transformation of biomass‐based C6‐platform chemical 5‐hydroxymethylfurfural (HMF) to 2,5‐diformylfuran (DFF) is reported. The molecular design and comparison of homogeneous (native, size‐enlarged) and solid‐supported (SiliaCAT, TurboBeads) TEMPOs is discussed for the oxidation in the ElectraSyn reactor with cost‐effective electrodes and green solvents. Computational modeling reveals the synergistic effect of the catalyst/base system and facilitated the catalyst design.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Can Organic Solvent Nanofiltration (OSN) be considered green? Is OSN greener than other downstream processing technologies? These are the two main questions addressed critically in the present ...review. Further questions dealt with in the review are as follows: What is the carbon footprint associated with the fabrication and disposal of membrane modules? How much solvent has to be processed by OSN before the environmental burden of OSN is less than the environmental burden of alternative technologies? What are the main challenges for improving the sustainability of OSN? How can the concept of Quality by Design (QbD) improve and assist the progress of the OSN field? Does the scale have an effect on the sustainability of membrane processes? The green aspects of OSN membrane fabrication, processes development and scale-up as well as the supporting concept of QbD, and solvent recovery technologies are critically assessed and future research directions are given, in this review.
Aspects of OSN membrane fabrication, processes development and scale-up are critically assessed and future research directions are suggested.
In this work we introduce a sustainable membrane-based synthesis–separation platform for enantioselective organocatalysis. An azido derivatized cinchona-squaramide bifunctional catalyst was ...synthesized and subsequently grafted to the surface of a polybenzimidazole-based nanofiltration membrane. The favorable effect of the covalent graftingdue to the change in geometry and increased secondary interactionson the catalytic activity due to conformational changes was confirmed by quantum chemical calculations. Asymmetric Michael and aza-Michael reactions of 1,3-dicarbonyl and indole, pyrazole, and triazole derivatives to β-nitrostyrene were performed with as high as 99% enantiomeric excess. This report on the enantioselective aza-Michael reaction of pyrazoles and triazoles opens new frontiers in the application of squaramide-based cinchona catalysts. A catalytic membrane cascade reactor was developed for an integrated synthesis–purification process allowing at least 98% product and substrate recovery, and quantitative in situ solvent recycling. The sustainability of the synthetic methodology was assessed through E-factor and carbon footprint.
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IJS, KILJ, NUK, PNG, UL, UM
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