Iron Impurity Impairs the CO Capture Performance of MgO: Insights from Microscopy and Machine Learning Molecular Dynamics.

Magnesium oxide (MgO) is a promising sorbent for direct air capture (DAC) of carbon dioxide. Iron (Fe) is a common impurity in naturally occurring MgO and minerals used to produce MgO, yet a molecular-scale understanding of Fe-doping effects on carbonation is lacking. Here, we observed reduced carbonation performance in Fe-doped MgO experimentally.

A New Triketone Ligand for Extraction of Lithium from Brines.

Recovery of lithium from brines by liquid-liquid solvent extraction (LLE) with diketones and synergistic co-ligands has been investigated for decades, but industrial application has been limited. In pursuit of a ligand with improved properties, a series of ketonamides with beta-carbonyl groups were designed, synthesized, and tested in extraction of lithium from sulfate and carbonate simulants of clay mineral tailing leachates. The best performing ligand, a novel tricarbonyl amide, was characterized for lithium extraction with and without four synergistic co-ligands.

Forming Micro-and Nano-Plastics from Agricultural Plastic Films for Employment in Fundamental Research Studies.

Microplastics (MPs) and nanoplastics (NPs) dispersed in agricultural ecosystems can pose a severe threat to biota in soil and nearby waterways. In addition, chemicals such as pesticides adsorbed by NPs can harm soil organisms and potentially enter the food chain. In this context, agriculturally utilized plastics such as plastic mulch films contribute significantly to plastic pollution in agricultural ecosystems.

Effects of soil particles and convective transport on dispersion and aggregation of nanoplastics via small-angle neutron scattering (SANS) and ultra SANS (USANS).

Terrestrial nanoplastics (NPs) pose a serious threat to agricultural food production systems due to the potential harm of soil-born micro- and macroorganisms that promote soil fertility and ability of NPs to adsorb onto and penetrate into vegetables and other crops. Very little is known about the dispersion, fate and transport of NPs in soils. This is because of the challenges of analyzing terrestrial NPs by conventional microscopic techniques due to the low concentrations of NPs and absence of optical transparency in these systems.

Deconstruction of biomass enabled by local demixing of cosolvents at cellulose and lignin surfaces.

A particularly promising approach to deconstructing and fractionating lignocellulosic biomass to produce green renewable fuels and high-value chemicals pretreats the biomass with organic solvents in aqueous solution. Here, neutron scattering and molecular-dynamics simulations reveal the temperature-dependent morphological changes in poplar wood biomass during tetrahydrofuran (THF):water pretreatment and provide a mechanism by which the solvent components drive efficient biomass breakdown. Whereas lignin dissociates over a wide temperature range (>25 °C) cellulose disruption occurs only above 150 °C.

Production of deuterated biomass by cultivation of Lemna minor (duckweed) in DO.

Common duckweed Lemna minor was cultivated in 50% DO to produce biomass with 50-60% deuterium incorporation containing cellulose with degree of polymerization close (85%) to that of HO-grown controls. The small aquatic plant duckweed, particularly the genus Lemna, widely used for toxicity testing, has been proposed as a potential source of biomass for conversion into biofuels as well as a platform for production of pharmaceuticals and specialty chemicals. Ability to produce deuterium-substituted duckweed can potentially extend the range of useful products as well as assist process improvement.

Hemicellulose-Cellulose Composites Reveal Differences in Cellulose Organization after Dilute Acid Pretreatment.

Model hemicellulose-cellulose composites that mimic plant cell wall polymer interactions were prepared by synthesizing deuterated bacterial cellulose in the presence of glucomannan or xyloglucan. Dilute acid pretreatment (DAP) of these materials was studied using small-angle neutron scattering, X-ray diffraction, and sum frequency generation spectroscopy. The macrofibril dimensions of the pretreated cellulose alone were smaller but with similar entanglement of macrofibrillar network as native cellulose.

Ultrastructure and Enzymatic Hydrolysis of Deuterated Switchgrass.

Neutron scattering of deuterated plants can provide fundamental insight into the structure of lignocellulosics in plant cell walls and its deconstruction by pretreatment and enzymes. Such plants need to be characterized for any alterations to lignocellulosic structure caused by growth in deuterated media. Here we show that glucose yields from enzymatic hydrolysis at lower enzyme loading were 35% and 30% for untreated deuterated and protiated switchgrass, respectively.

Hemicellulose characterization of deuterated switchgrass.

This work describes the structural characterization of hemicellulose isolated from hydroponically grown switchgrass in HO medium (protiated) or 50% DO medium (deuterated) through compositional analysis, GPC, FTIR, C and H/C HSQC NMR. 4-O-methyl glucuronoarabinoxylan (GAX), the major hemicellulose in switchgrass isolated from deuterated switchgrass, had structural properties similar to hemicellulose isolated from protiated switchgrass. Both had comparable arabinose to xylose ratio (0.

Bacterial Cellulose Ionogels as Chemosensory Supports.

To fully leverage the advantages of ionic liquids for many applications, it is necessary to immobilize or encapsulate the fluids within an inert, robust, quasi-solid-state format that does not disrupt their many desirable, inherent features. The formation of ionogels represents a promising approach; however, many earlier approaches suffer from solvent/matrix incompatibility, optical opacity, embrittlement, matrix-limited thermal stability, and/or inadequate ionic liquid loading. We offer a solution to these limitations by demonstrating a straightforward and effective strategy toward flexible and durable ionogels comprising bacterial cellulose supports hosting in excess of 99% ionic liquid by total weight.

Allelopathic effects of exogenous phenylalanine: a comparison of four monocot species.

Exogenous phenylalanine stunted annual ryegrass but not switchgrass or winter grain rye, with deuterium incorporation up to 3% from phenyalanine-d . Toxicity to duckweed varied with illumination intensity and glucose uptake. Isotopic labeling of biomolecules through biosynthesis from deuterated precursors has successfully been employed for both structural studies and metabolic analysis.

Development of approaches for deuterium incorporation in plants.

Soon after the discovery of deuterium, efforts to utilize this stable isotope of hydrogen for labeling of plants began and have proven successful for natural abundance to 20% enrichment. However, isotopic labeling with deuterium ((2)H) in higher plants at the level of 40% and higher is complicated by both physiological responses, particularly water exchange through transpiration, and inhibitory effects of D2O on germination, rooting, and growth. The highest incorporation of 40-50% had been reported for photoheterotrophic cultivation of the duckweed Lemna.

Production of bacterial cellulose with controlled deuterium-hydrogen substitution for neutron scattering studies.

Isotopic enrichment of biomacromolecules is a widely used technique that enables the investigation of the structural and dynamic properties to provide information not accessible with natural abundance isotopic composition. This study reports an approach for deuterium incorporation into bacterial cellulose. A media formulation for growth of Acetobacter xylinus subsp.

Production of deuterated switchgrass by hydroponic cultivation.

The bioenergy crop switchgrass was grown hydroponically from tiller cuttings in 50 % D 2 O to obtain biomass with 34 % deuterium substitution and physicochemical properties similar to those of H 2 O-grown switchgrass controls. Deuterium enrichment of biological materials can potentially enable expanded experimental use of small angle neutron scattering (SANS) to investigate molecular structural transitions of complex systems such as plant cell walls. Two key advances have been made that facilitate cultivation of switchgrass, an important forage and biofuel crop, for controlled isotopic enrichment: (1) perfusion system with individual chambers and (2) hydroponic growth from tiller cuttings.

Crystallization and preliminary X-ray diffraction analysis of Hypocrea jecorina Cel7A in two new crystal forms.

Cel7A (previously known as cellobiohydrolase I) from Hypocrea jecorina was crystallized in two crystalline forms, neither of which have been previously reported. Both forms co-crystallize under the same crystallization conditions. The first crystal form belonged to space group C2, with unit-cell parameters a=152.

Effect of D2O on growth properties and chemical structure of annual ryegrass (Lolium multiflorum).

The development of deuterated biomass is essential for effective neutron scattering studies on biomass, which can provide key insights into the complex biomass conversion processes. A method for optimized production of deuterated annual ryegrass (Lolium multiflorum) was developed by growing the plants in 50% D2O in perfused hydroponic chambers. Deuterium incorporation of 36.

The effect of deuteration on the structure of bacterial cellulose.

In vivo generated deuterated bacterial cellulose, cultivated from 100% deuterated glycerol in D2O medium, was analyzed for deuterium incorporation by ionic liquid dissolution and (2)H and (1)H nuclear magnetic resonance (NMR). A solution NMR method of the dissolved cellulose was used to determine that this bacterial cellulose had 85% deuterium incorporation. Acetylation and (1)H and (2)H NMR of deuterated bacterial cellulose indicated near equal deuteration at all sites of the glucopyranosyl ring except C-6 which was partly deuterated.

Deuterium incorporation in biomass cell wall components by NMR analysis.

A commercially available deuterated kale sample was analyzed for deuterium incorporation by ionic liquid solution (2)H and (1)H nuclear magnetic resonance (NMR). This protocol was found to effectively measure the percent deuterium incorporation at 33%, comparable to the 31% value determined by combustion. The solution NMR technique also suggested by a qualitative analysis that deuterium is preferentially incorporated into the carbohydrate components of the kale sample.

Small angle neutron scattering reveals pH-dependent conformational changes in Trichoderma reesei cellobiohydrolase I: implications for enzymatic activity.

Cellobiohydrolase I (Cel7A) of the fungus Trichoderma reesei (now classified as an anamorph of Hypocrea jecorina) hydrolyzes crystalline cellulose to soluble sugars, making it of key interest for producing fermentable sugars from biomass for biofuel production. The activity of the enzyme is pH-dependent, with its highest activity occurring at pH 4-5. To probe the response of the solution structure of Cel7A to changes in pH, we measured small angle neutron scattering of it in a series of solutions having pH values of 7.

SANS study of cellulose extracted from switchgrass.

Lignocellulosic biomass, which is an abundant renewable natural resource, has the potential to play a major role in the generation of renewable biofuels through its conversion to bioethanol. Unfortunately, it is a complex biological composite material that shows significant recalcitrance, making it a cost-ineffective feedstock for bioethanol production. Small-angle neutron scattering (SANS) was employed to probe the multi-scale structure of cellulosic materials.

Characterization of biochars produced from cornstovers for soil amendment.

Through cation exchange capacity assay, nitrogen adsorption-desorption surface area measurements, scanning electron microscopic imaging, infrared spectra and elemental analyses, we characterized biochar materials produced from cornstover under two different pyrolysis conditions, fast pyrolysis at 450 °C and gasification at 700 °C. Our experimental results showed that the cation exchange capacity (CEC) of the fast-pyrolytic char is about twice as high as that of the gasification char as well as that of a standard soil sample. The CEC values correlate well with the increase in the ratios of the oxygen atoms to the carbon atoms (O:C ratios) in the biochar materials.

Breakdown of cell wall nanostructure in dilute acid pretreated biomass.

The generation of bioethanol from lignocellulosic biomass holds great promise for renewable and clean energy production. A better understanding of the complex mechanisms of lignocellulose breakdown during various pretreatment methods is needed to realize this potential in a cost and energy efficient way. Here we use small-angle neutron scattering (SANS) to characterize morphological changes in switchgrass lignocellulose across molecular to submicrometer length scales resulting from the industrially relevant dilute acid pretreatment method.

Metabolic prosthesis for oxygenation of ischemic tissue.

This communication discloses new ideas and preliminary results on the development of a metabolic prosthesis for local oxygenation of ischemic tissue under physiologically neutral conditions. We report for the first time selective electrolysis of physiological saline by repetitively pulsed, charge-limited electrolysis for the production of oxygen and suppression of free chlorine. Using 800-microA amplitude current pulses and < 200 micros pulse duration, we demonstrate prompt oxygen production and delayed chlorine production at the surface of a fused 0.

Spontaneous high-yield production of hydrogen from cellulosic materials and water catalyzed by enzyme cocktails.

Cocktail reception: Biohydrogen is produced in high yield from cellulosic materials and water in a one-pot process catalyzed by up to 14 enzymes and one coenzyme. This assembly of enzymes results in non-natural catabolic pathways. These spontaneous reactions are conducted under modest reaction conditions (32 degrees C and atmospheric pressure).