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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO{sub 2} balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry), melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength)

36 MATERIALS SCIENCE↗
DOE OSTI2016

Potentiodynamic studies of Ni-P-TiO{sub 2} nano-composited coating on the mild steel deposited by electroless plating method

Now a days, corrosion studies are important for reducing the wastage of metals. The importance of corrosion studies is two folds i.e. first is economic, including the reduction of material losses resulting from the wasting away or sudden failure of materials and second is conservation Electroless process is an autocatalytic reduction method in which metallic ions are reduced in the solution. Nanocomposite coatings of Ni-P-TiO{sub 2} on mild steel are deposited by varying volume of TiO{sub 2} nano-powder by electroless method from Ni-P plating bath containing Nickel Sulphate as a source of nickel ions, sodium hypophosphite as the reducing agent, lactic acid as a complexing agents and TiO{sub 2} nano powder. Electroless Ni-P-TiO{sub 2} coating have been widely used in the chemical process industries, mechanical industries, electronic industries and chloroalkali industries due to their excellent corrosion with mechanical properties. In the present work, deposition of Ni-P alloy coating and Ni-P-TiO{sub 2} nanocomposited coatings were done on the mild steel and corrosion properties were studied with Potentio-dynamic polarization measurements method in 3.5 wt% sodium chloride solution. It showed in the experiments that Ni-P-TiO{sub 2} nanocomposited coating has better corrosion resistance as comparedthan Ni-P alloy coating. Morphological studies were done by field emission scanning electron microscopy (FESEM), energy–dispersive analysis of X-ray (EDAX) and X-ray diffraction (XRD). These studies confirmed the deposition of Ni-P alloy coating and Ni-P-TiO{sub 2} nanocomposited coating.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Comparative genomics of Fructobacillus spp. and Leuconostoc spp. reveals niche-specific evolution of Fructobacillus spp.

In this study, Fructobacillus spp. in fructose-rich niches belong to the family Leuconostocaceae . They were originally classified as Leuconostoc spp., but were later grouped into a novel genus, Fructobacillus , based on their phylogenetic position, morphology and specific biochemical characteristics. The unique characters, so called fructophilic characteristics, had not been reported in the group of lactic acid bacteria, suggesting unique evolution at the genome level. Here we studied four draft genome sequences of Fructobacillus spp. and compared their metabolic properties against those of Leuconostoc spp. As a result, Fructobacillus species possess significantly less protein coding sequences in their small genomes. The number of genes was significantly smaller in carbohydrate transport and metabolism. Several other metabolic pathways, including TCA cycle, ubiquinone and other terpenoid-quinone biosynthesis and phosphotransferase systems, were characterized as discriminative pathways between the two genera. The adhE gene for bifunctional acetaldehyde/alcohol dehydrogenase, and genes for subunits of the pyruvate dehydrogenase complex were absent in Fructobacillus spp. The two genera also show different levels of GC contents, which are mainly due to the different GC contents at the third codon position. In conclusion, the present genome characteristics in Fructobacillus spp. suggest reductive evolution that took place to adapt to specific niches.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2018

Biodegradation in Soil of PLA/PBAT Blends Compatibilized with Chain Extender

This paper presents a study of biodegradation, in soil, of samples of poly(butylene adipate-co-terephthalate)(PBAT), poly(lactic acid) (PLA) and blends of these materials prepared in torque rheometer with the addition of a chain extender. Film samples of these materials were buried in soil under controlled laboratory conditions. The degraded samples were regularly taken from soil and analyzed by visual inspection, size exclusion chromatography, differential scanning calorimetry and infrared spectroscopy. Respirometry biodegradation tests were conducted to assess samples mineralization degree. Blends showed higher degree of crystallinity compared to pure polymers. Crystallinity degree enhanced during the biodegradation process in all samples, being able to causing the samples to degrade slowly. The study showed the great complexity of the biodegradation process of PLA and PBAT blends when compatibilized with a chain extender. The biodegradation rate showed different results depending on the characteristic applied to evaluate it: visual, molecular weight or mineralization. The chain extender had strong influence in PBAT and blends degradation, slowing the process as observed by the variation of molecular weight and carbonyl index. Blends showed an intermediate behavior compared to the original polymers.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Aerobic oxidation of glycerol catalyzed by M salts of PMo 12 O 40 3- (M = K + , Zn 2+ , Cu 2+ , Al 3+ , Cr 3+ , Fe 3+ )

Glycerol is a co-product in the manufacture of biodiesel from vegetable oil and animal fat. A significant increase in biodiesel production results in adramatic overproduction of glycerol. The oxidation of glycerol to lactic acid (LA) by O 2 is considered to be a promising technology to increase the value of glycerol. Studies on the fundamental reaction mechanism vary for different catalytic systems. Here in this work we have chosen Keggin polyoxometalates (POMs) as an exemplary family of water-soluble hydrolytically and oxidatively-stable, fully-inorganic complexes with transition-metal and non-transition-metal counter-cations (M in the formula, MPMo 12 O 40 , where M = H + , K + , Zn 2+ , Cu 2+ , Al 3+ , Cr 3+ , Fe 3+ in appropriate number to counterbalance the 3- charge of PMo 12 O 40 3- ). Reactions involving hydrogen peroxide, an intermediate during glycerol oxidation, produce free radicals. A kinetic analysis reveals that the radical chain length under typical conditions is about 20–30. After minimal optimization, the yield of LA was 88% at glycerol conversion > 97% (1.0 M aqueous solution of glycerol, 4.0 mM of the Al salt of PMo 12 O 40 3- , henceforth “AlPMo”, 10 bar O 2 at 60 °C, reaction time 6.0 h).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Controlling Bacterial Contamination During Fuel Ethanol Fermentation Using Thermochemically Depolymerized Lignin Bio-Oils

Lactic acid bacteria (LAB) contamination during fuel ethanol fermentation can lead to significant economic loses. To circumvent this, fuel ethanol plants add antibiotics prophylactically, but their overuse has resulted in the emergence of antibiotic-resistant LAB strains. Lignin is a sustainable biopolymer that can be found as a waste product from lignocellulosic biorefineries. Technical lignins and their smaller phenolic subunits have been shown to exhibit broad-spectrum antimicrobial properties, but there is a lack of demonstrations of lignin derivatives with highly selective properties in the literature. Here, corn stover lignin from a biorefinery was oxidatively depolymerized using an environmentally benign organic oxidant, peracetic acid, into a bio-oil that has selective antimicrobial properties against LAB and not yeasts. The resulting bio-oil demonstrated up to 90% inhibition of commercially sampled LAB (including antibiotic-resistant strains) at 4 mg ml-1 with no inhibition against an industrial yeast strain. These antimicrobial properties of the bio-oil are attributed to larger unidentified lignin oligomers, compared to monolignols, that have a membrane damaging mode of action. Using the bio-oil (4 mg ml-1) during simultaneous saccharification and fermentation (SSF) of raw corn starch showed no inhibition of enzymatic activity, and in LAB contaminated fermentations the bio-oil treatments showed an 8% increase in ethanol yields at higher bacterial contamination ratios (l : 100 yeast to LAB, CFU per ml). This study illustrates the efficacy of using lignin bio-oil as an antibiotic replacement during fuel ethanol fermentation and demonstrates the highly selective antimicrobial properties of lignin oligomers, which creates a viable lignin valorization strategy for biorefineries.

bio-oil↗
DOE OSTI2016

Correlation between crystallization behaviour and interfacial interactions in plasticized PLA/POSS nanocomposites

In this study, the correlation between crystallization behavior and surface chemistry of polyhedral oligomeric silsesquioxanes (POSS) for plasticized poly(lactic acid) (PLA)/POSS nanocomposites was investigated. Four different kinds of POSS particles having different chemical structures were used. Poly(ethylene glycol) (PEG, 8000 g/mol) was utilized as the plasticiser. The nanocomposites were melt-compounded in an Xplore Instruments 15 cc twin screw microcompounder at 180°C barrel temperature and 100 rpm screw speed. Non-isothermal crystallization behaviour of PLA/PEG/POSS nanocomposites were evaluated from common kinetic models such as Avrami and Avrami-Ozawa and Kissinger by using the thermal data obtained from differantial scanning calorimetry (DSC). A polarized optical microscope (POM) equipped with a hot-stage was used to examine the morphology during the crystal growth. In order to investigate the interfacial interactions between POSS particles and plasticized PLA, thermodynamic work of adhesion approach was adopted using the experimentally determined surface energies. A strong correlation was obtained between interfacial chemistry and the nucleation rate in plasticized PLA/POSS nanocomposites. It was found that the polar interactions were the dominating factor which determines the nucleation activity of the POSS particles.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Effect of Natural Glyceryl Tributyrate as Plasticizer and Compatibilizer on the Performance of Bio-Based Polylactic Acid/poly(3-hydroxybutyrate) Blends

Bio-based poly(lactic acid)/poly(3-hydroxybutyrate) (PLA/PHB) films were melt-blended with a natural hydrophobic plasticizer (glyceryl tributyrate, TB) at three different concentrations (10, 15 and 20% by weight per 100 parts of the blends) to study the effect of TB on the final properties of the materials. The pursued aim was to obtain a material with potential use in the packaging industry. Two different PLA/PHB ratios were used, 70/30 and 60/40, respectively. A full characterization of the developed blends was carried out, including the morphological, thermal, mechanical and barrier properties. The thermal test revealed the immiscibility between PLA and PHB by showing two glass transition temperatures for the blends and biphasic melt. Mechanical tests showed the increased in the elongation at break as the plasticizer content in films increased. The incorporation of PHB crystals in the PLA matrix displayed an improvement in the water barrier properties of materials. Finally, formulations PLA/PHB-TB with 15 wt% of plasticizer presented the best combination of properties suitable for the intended use in films manufacturing, showing toughness and ductility, good water barrier properties and transparency with slightly amber color.

36 MATERIALS SCIENCE↗
DOE OSTI2015

3D TEM reconstruction and segmentation process of laminar bio-nanocomposites

The microstructure of laminar bio-nanocomposites (Poly (lactic acid)(PLA)/clay) depends on the amount of clay platelet opening after integration with the polymer matrix and determines the final properties of the material. Transmission electron microscopy (TEM) technique is the only one that can provide a direct observation of the layer dispersion and the degree of exfoliation. However, the orientation of the clay platelets, which affects the final properties, is practically immeasurable from a single 2D TEM image. This issue can be overcome using transmission electron tomography (ET), a technique that allows the complete 3D characterization of the structure, including the measurement of the orientation of clay platelets, their morphology and their 3D distribution. ET involves a 3D reconstruction of the study volume and a subsequent segmentation of the study object. Currently, accurate segmentation is performed manually, which is inefficient and tedious. The aim of this work is to propose an objective/automated segmentation methodology process of a 3D TEM tomography reconstruction. In this method the segmentation threshold is optimized by minimizing the variation of the dimensions of the segmented objects and matching the segmented V{sub clay} (%) and the actual one. The method is first validated using a fictitious set of objects, and then applied on a nanocomposite.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2024

Improving the Recyclability of Polymer Composites With Cellulose Nanofibrils

Cellulose nanofibers (CNFs) have been widely studied for their reinforcing potential in high-performance composites. While there are numerous publications on CNF-reinforced composites in a variety of polymer matrices, few have considered the recyclability of such thermoplastic composites and whether the incorporation of CNFs deteriorates or improves their performance upon reprocessing. In this study, two thermoplastic resins, poly(lactic acid) (PLA), and glycol-modified polyethylene terephthalate (PETg), were prepared with CNF reinforcement and thermomechanically recycled to investigate the effect of CNF inclusion on the composite properties after reprocessing as well as their effect on the composites’ number of useful life cycles. Additionally, changes in mechanical, thermal, rheological, molecular, and microstructural properties of the composites and/or base resins were monitored as a function of cycle numbers. As is typical, the polymers’ molecular weight and mechanical performance deteriorated with continued processing. However, the addition of spray dried CNF was found to better maintain the mechanical performance of both polymers throughout multiple recycling steps as compared to neat samples. For example, the tensile strength of PETg with 20 wt% CNF after 6 processing cycles was found to exceed that of virgin neat PETg, and higher loadings of CNF were found to preserve a higher yield strength during multiple rounds of reprocessing compared to PETg composites with lower CNF loadings. Ultimately this study indicates that the addition of CNF to some thermoplastic materials can increase both their sustainability by offsetting the use of high-embodied energy resins and their circularity by enabling performance retention over more use cycles.

42 ENGINEERING↗
DOE OSTI2019

Balloon-Expandable Biodegradable Stents Versus Self-Expandable Metallic Stents: A Comparison Study of Stent-Induced Tissue Hyperplasia in the Rat Urethra

Purpose: To compare the degrees of stent-induced tissue hyperplasia of balloon-expandable, biodegradable stents (BEBSs) with those of self-expandable metallic stents (SEMSs) in a rat urethral model. Materials and Methods: A total of 20 rats were randomized into two groups. The BEBS group (n = 10) received a poly-l-lactic acid (PLLA) biodegradable stent. The SEMS group (n = 10) received a nitinol bare stent. All rats were killed eight weeks after stent placement. The degree of stent-induced tissue hyperplasia was assessed by comparing the results of retrograde urethrography and histologic examination between the two groups. Results: Stent placement was technically successful in all rats. Two rats in the BEBS group were excluded due to procedure-related death. The mean luminal diameter of stented urethra on urethrograms was not significantly different at 4 and 8 weeks between the two groups. On histologic analysis, the percentage of granulation tissue area (p < 0.001) and the thickness of papillary projection (p < 0.001) were significantly higher in the BEBS group compared with the SEMS group. The inflammatory cell infiltration showed a clear tendency to significance (p = 0.050). There were no statistical differences in the number of epithelial layers and the thickness of submucosal fibrosis between the two groups. Conclusion: Formation of stent-induced tissue hyperplasia was significantly evident in the rat urethra with similar degrees between the BEBS and the SEMS. The BEBS was associated with a thicker papillary projection and larger granulation tissue area resulting from higher inflammation compared with the SEMS.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

The Effect of Acetylation on the Hydrolytic Degradation of PLA/Clay Nanocomposites

In this study, the hydrolytic degradation of Poly(lactic acid) (PLA) and acetylated PLA (PLA-Ac)–clay nanocomposites were investigated. The organo clay was obtained by ion exchange reaction using cetyl tri methyl ammonium bromide (CTAB). Nanocomposites containing 2, 5 and 8% mass ratio of organo clay (CTAB-O) were prepared. PLA and its organo clay nanocomposites were characterized by scanning electron microscope (SEM), thermo gravimetric analysis (TGA) and X-ray diffraction (XRD) to determine the morphology before and after hydrolytic degradation. Fourier transform infrared (FTIR) analyses of PLA and PLA-Ac were also obtained. The hydrolytic degradation of polymers and their composites were investigated in the phosphate buffered saline solution (PBS). The results showed that controlled hydrolytic degradation was observed in the samples with end group modification of PLA. While weight loss of PLA films was 28%, that of PLA-Ac films was 18% after 60 days degradation time. The weight loss was obtained as 29.5 and 25.5% for PLA-5 wt% organo clay (PLA/5CTAB-O) and PLA-Ac-5 wt% organo clay (PLA-Ac/5CTAB-O) nanocomposites films, respectively. It was also observed that thermal degradation of PLA-Ac was much more than that of PLA. Hydrolytic degradation increased depending on organo clay content. The end group modificated PLA results in controlled hydrolytic degradation. While hydrolytic degradation in polymer films occurred as surface erosion, bulk erosion was observed in composite films.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2013

The role of 3D microenvironmental organization in MCF-7 epithelial–mesenchymal transition after 7 culture days

We present a multi-technique study on in vitro epithelial–mesenchymal transition (EMT) in human MCF-7 cells cultured on electrospun scaffolds of poly(L-lactic acid) (PLA), with random and aligned fiber orientations. Our aim is to investigate the morphological and genetic characteristics induced by extracellular matrix in tumor cells cultured in different 3D environments, and at different time points. Cell vitality was assessed with AlamarBlue at days 1, 3, 5 and 7. Scanning electron microscopy was performed at culture days 3 and 7. Immunohistochemistry (for E-cadherin, β-catenin, cytokeratins, nucleophosmin, tubulin, Ki-67 and vimentin), immunofluorescence (for F-actin) western blot (for E-cadherin, β-catenin and vimentin) and transmission electron microscopy were carried out at day 7. An EMT gene array followed by PCR analysis confirmed the regulation of selected genes. At day 7, scanning electron microscopy on aligned-PLA revealed spindle-shaped cells gathered in buds and ribbon-like structures, with a higher nucleolar/nuclear ratio and a loss in E-cadherin and β-catenin at immunohistochemistry and western blot. An up-regulation of SMAD2, TGF-β2, TFPI2 and SOX10 was found in aligned-PLA compared to random-PLA cultured cells. The topography of the extracellular matrix has a role in tumor EMT, and a more aggressive phenotype characterizes MCF-7 cells cultured on aligned-PLA scaffold. -- Highlights: • After 7 culture days an aligned-PLA scaffold induces a spindle shape to MCF-7 cells. • Despite these changes, the aligned MCF-7 cells keep an epithelial phenotype. • The extracellular environment alone influences the E-cadherin/β-catenin axis. • The extracellular environment can promote the epithelial–mesenchymal transition.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Nano Graphene-Reinforced Bio-nanocomposites Based on NR/PLA: The Morphological, Thermal and Rheological Perspective

Bio-based graphene-reinforced thermoplastic elastomers (TPE) based on natural rubber (NR), and poly lactic acid (PLA) were successfully prepared via melt blending. The effect of graphene nanosheets (GNS) content and coupling agent were investigated on morphological, thermal and rheological properties of the PLA/NR/GNS bio-nanocomposites. More stable morphology of uniformly dispersed NR phase in the continuous PLA matrix with a relatively narrower diameter-size distribution was achieved in the presence of a compatibilizer. Moreover, transmission electron micrographs showed more improved dispersion of GNS with predominantly exfoliated morphology in the case of ENR-compatibilized PLA/NR/GNS bio-nanocomposites. Crystallization/melting studies revealed that, as the GNS content increased, the cold-crystallization peak, melting peak and glass-to-rubber transition temperature values shifted to higher temperatures and the crystallinities of blends slightly decreased (about 7%) which might be attributed to the reduction of polymeric segments mobility by the restricting effect of GNS. Dynamical mechanical investigation showed that the storage modulus (E′) increased about 25% by the introduction of GNS due to the inherent stiffness of GNS and the occurrence of compatibility in the PLA/NR blend in the presence of ENR. The presence of ENR shifted the T{sub g} of the NR phase and the PLA matrix towards each other which is a characteristic of higher miscibility and compatibility. The thermogravimetry (TGA) and derivative thermogravimetry (DTG) curves revealed higher thermal stability of the compatibilized-PLA/NR blends due to the enhanced interfacial adhesion and the homogenous dispersion of GNSs as direct effects of the presence of ENR. Rheological studies indicated that the formation of the effective GNS-polymer networks by the presence of ENR increased the storage modulus (G′) and complex viscosity (η*) value due to the effectiveness of the GNS in taking loads and restricted molecular motion, respectively. Graphical Abstract: .

36 MATERIALS SCIENCE↗
DOE OSTI2012

Magnetic Resonance Imaging-Based Radiation-Absorbed Dose Estimation of {sup 166}Ho Microspheres in Liver Radioembolization

Purpose: To investigate the potential of magnetic resonance imaging (MRI) for accurate assessment of the three-dimensional {sup 166}Ho activity distribution to estimate radiation-absorbed dose distributions in {sup 166}Ho-loaded poly (L-lactic acid) microsphere ({sup 166}Ho-PLLA-MS) liver radioembolization. Methods and Materials: MRI, computed tomography (CT), and single photon emission CT (SPECT) experiments were conducted on an anthropomorphic gel phantom with tumor-simulating gel samples and on an excised human tumor-bearing liver, both containing known amounts of {sup 166}Ho-PLLA-MS. Three-dimensional radiation-absorbed dose distributions were estimated at the voxel level by convolving the {sup 166}Ho activity distribution, derived from quantitative MRI data, with a {sup 166}Ho dose point-kernel generated by MCNP (Monte Carlo N-Particle transport code) and from Medical Internal Radiation Dose Pamphlet 17. MRI-based radiation-absorbed dose distributions were qualitatively compared with CT and autoradiography images and quantitatively compared with SPECT-based dose distributions. Both MRI- and SPECT-based activity estimations were validated against dose calibrator measurements. Results: Evaluation on an anthropomorphic phantom showed that MRI enables accurate assessment of local {sup 166}Ho-PLLA-MS mass and activity distributions, as supported by a regression coefficient of 1.05 and a correlation coefficient of 0.99, relating local MRI-based mass and activity calculations to reference values obtained with a dose calibrator. Estimated MRI-based radiation-absorbed dose distributions of {sup 166}Ho-PLLA-MS in an ex vivo human liver visually showed high correspondence to SPECT-based radiation-absorbed dose distributions. Quantitative analysis revealed that the differences in local and total amounts of {sup 166}Ho-PLLA-MS estimated by MRI, SPECT, and the dose calibrator were within 10%. Excellent agreement was observed between MRI- and SPECT-based dose-volume histograms. Conclusions: Quantitative MRI was demonstrated to provide accurate three-dimensional {sup 166}Ho-PLLA-MS activity distributions, enabling localized intrahepatic radiation-absorbed dose estimation by convolution with a {sup 166}Ho dose point-kernel for liver radioembolization treatment optimization and evaluation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2017

Enhanced anti-counterfeiting measures for additive manufacturing: coupling lanthanide nanomaterial chemical signatures with blockchain technology

The significant rise of additive manufacturing (AM) in recent years is in part due to the open sourced nature of the printing processes and reduced cost and capital barriers relative to traditional manufacturing. However, this democratization of manufacturing spurs an increased demand for producers and end-users to verify the authenticity and quality of individual parts. To this end, we introduce an anti-counterfeiting method composed of first embedding engineered nanomaterials into features of a 3D-printed part followed by non-destructive interrogation of these features to quantify a chemical signature profile. The part specific chemical signature data is then linked to a securitized, distributed, and time-stamped blockchain ledger entry. To demonstrate the utility of this approach, lanthanide-aspartic acid nanoscale coordination polymers (Ln3+- Asp NCs) / poly(lactic) acid (PLA) composites were formulated and transformed into a filament feedstock for fused deposition modeling (FDM) 3D printing. In the present case, a quick-response (QR) code containing the doped Ln3+-Asp NCs was printed using a dual-extruder FDM printer into pure PLA parts. The QR code provides a searchable reference to an Ethereum-based blockchain entry. The QR code physical features also serve as defined areas to probe the signatures arising from the embedded Ln3+-Asp NCs. Visible fluorescence emission with UV-excitation was quantified in terms of color using a smartphone camera and incorporated into blockchain entries. Ultimately, linking unique chemical signature data to blockchain databases is anticipated to make the costs of counterfeiting AM materials significantly more prohibitive and transactions between those in the supply chain more trustworthy.

Additive Manufacturing↗
DOE OSTI2020

Rewired phenolic metabolism and improved saccharification efficiency of a Zea mays cinnamyl alcohol dehydrogenase 2 (zmcad2) mutant

Lignocellulosic biomass is an abundant byproduct from cereal crops that can potentially be valorized as a feedstock to produce biomaterials. Zea mays CINNAMYL ALCOHOL DEHYDROGENASE 2 (ZmCAD2) is involved in lignification, and is a promising target to improve the cellulose–to–glucose conversion of maize stover. Here, we analyzed a field–grown zmcad2 Mutator transposon insertional mutant. Zmcad2 mutant plants had an 18% lower Klason lignin content, whereas their cellulose content was similar to that of control lines. The lignin in zmcad2 mutants contained increased levels of hydroxycinnamaldehydes, i.e. the substrates of ZmCAD2, ferulic acid and tricin. Ferulates decorating hemicelluloses were not altered. Phenolic profiling further revealed that hydroxycinnamaldehydes are partly converted into (dihydro)ferulic acid and sinapic acid and their derivatives in zmcad2 mutants. Syringyl lactic acid hexoside, a metabolic sink in CAD–deficient dicot trees, appeared not to be a sink in zmcad2 maize. The enzymatic cellulose–to–glucose conversion efficiency was determined after 10 different thermochemical pre–treatments. Zmcad2 yielded significantly higher conversions compared with controls for almost every pre–treatment. However, the relative increase in glucose yields after alkaline pre–treatment was not higher than the relative increase when no pre–treatment was applied, suggesting that the positive effect of the incorporation of hydroxycinnamaldehydes was leveled off by the negative effect of reduced p–coumarate levels in the cell wall. Here, taken together, our results reveal how phenolic metabolism is affected in CAD–deficient maize, and further support mutating CAD genes in cereal crops as a promising strategy to improve lignocellulosic biomass for sugar–platform biorefineries.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

UFMP and CAW Bioreactor Metagenome

CSTR anaerobic bioreactors fed UltraFiltered Milk Permeate (UFMP) and Cottage cheese Acid Whey (CAW) were inoculated with acid sludge microbial communities and monitored overtime for lactic acid production. Samples were taken for metagenomics analyses.

bioreactor metagenome↗