Substitution effects of metal quinolate chelate materials for organic electroluminescence applications

A technology that shows great promise for application in novel flat panel displays is based on electroluminescence (EL) of organic light-emitting devices (OLEDs). Aluminum tris(8-hydroxy quinoline) (Alq3)-type materials are very important as emitter materials in OLEDs. Systematic experimental and theoretical studies of these materials are crucial in order to elucidate the relationship between structure and function of EL materials and ultimately optimize device performance. It has been demonstrated both theoretically and experimentally that the photoluminescence (PL) emission energies of Alq 3 can be tuned by adding substituents to the quinolate ligand. The electronic and structural changes associated with such substitutions can dramatically affect the resulting PL and EL efficiencies. The first systematic study of the PL and EL properties of a series of methyl-substituted quinolate tris-chelates of aluminum, gallium, and indium is reported. Detailed description of synthetic routes, characterization results, photophysical data, device data, and x-ray absorption data are presented. The effect of methyl and metal ion substitution on EL is discussed with respect to changes in required parameters

UV-Vis Characterization of Aromatic Content in Bio-oil

Bio-oil is a renewable fuel source with the potential to replace fossil fuels. Characterization of the composition of bio-oil is of interest to many scientists. Bio-oil is composed of hundreds of molecules making characterization a difficult and time consuming task. Various methods have been investigated as viable methods for separation and characterization. In this work, UV-Vis Spectroscopy is utilized to investigate the aromatic content of various bio-oils. Standard addition is method where a known amount of standard is added to a sample of interest. Using the Beer-Lambert law, the graph can be extrapolated to quantify the amount of target compound in a mixture. Results indicate this method is a viable strategy for quantifying target compounds and provides preliminary quantitative data on the aromatic content of bio-oils tested

Characterization of hydroprocessed fast pyrolysis oil fractions

Production of renewable fuel from biomass has both environmental and national security implications. Considering that liquid transportation fuels massively affects the way we live, technology to produce fuels need to be both technologically-appropriate and economical. Fast pyrolysis remains as one of the most promising thermochemical processing technologies for converting solid biomass into a liquid that can be further upgraded into hydrocarbon fuels. The presence of various types of oxygen-containing functional groups confer pyrolysis oils with unwanted fuel properties such as acidity and low heating value. In order to remove these oxygen functionalities, catalytic hydrodeoxygenation or hydroprocessed is needed. This process involves the catalytic treatment of pyrolysis oils at high temperature and high pressure hydrogen, similar to that employed in the petroleum industry to remove sulfur from crude oil. However, hydroprocessed fast pyrolysis oil is complicated by both the thermal and chemical instability of the pyrolysis oil itself and the presence of water, giving importance to proper catalysts design considerations. Hydroprocessing further produces water and COx gas species as a means to expel the oxygen. The aqueous phase typically contains very low to negligible amount of carbon while the organic phase will contain a mixture of hydrocarbons. If the degree of deoxygenation is lower, larger amounts of carbon are present in the aqueous phase while recalcitrant oxygen species, like phenols and carboxylic acids appear in the organic phase. This in turn can affect the composition of the different fractions generated after distillation of the organic phase product. This presentation aims to discuss both the characterization of the various hydrotreated fast pyrolysis oil fractions, including elemental, 13C NMR and autoignition properties. It will also describe the hydrotreating processes used to obtain the different degrees of deoxygenation. References: Olarte MV, Padmaperuma AB, Ferrell JR III, Christensen, ED, Hallen RT, Lucke RB, Burton SD, Lemmon TL, Swita MS, Chupka G, Elliott DC, Drennan C. 2017. “Characterization of upgraded fast pyrolysis oak oil distillate fractions from sulfided and non-sulfided catalytic hydrotreating”. Fuel. 202: 620 – 630. Olarte MV, Albrecht KA, Bays, TJ, Polikarpov E, Maddi B, Linehan JC, O’Hagan MJ, Gaspar DJ. 2019. “Autoignition and select properties of low sample volume thermochemical mixtures from renewable sources”. Fuel. 238: 493 – 506

Microalgal co-cultures for biomanufacturing applications.

High demands in consumer goods and pressures from governments to meet environmental regulations have pushed industries to find innovative, carbon-neutral solutions. Sustainable methods in biotechnology are sought to increase productivity whilst keeping at bay one of the major problems in monoculture production routes: contamination. The use of engineered consortia is seen as a viable option. In nature, microorganisms exist as part of complicated networks known as consortia. Within the consortia, each member plays a role in facilitating communication, tasks distribution, nutrients acquisition and protection. This emerging field uses the conundrums that govern natural microbial assemblages to create artificial co-culture within the laboratory. Purpose fit, co-cultures have been created, to enhance productivity yields of desired products, for bioremediation and to circumvent contamination. The use of microalgae in co-cultures is the focus of this study. Microalgae have application in many fields and are ideal candidates for bioproduction and carbon sequestration. The results of two different systems are presented, which aim to increase the productivity of microalgae biomass and of β-carotene or lipids. The natural consortium of Dunaliella salina, Halomonas and Halobacterium salinarum showed both an increase in microalgae cell concentration by 79% and higher β-carotene productivity compared to the monoculture. This association also showed that Halomonas is able to aid D. salina when subjected to abiotic stress. The artificial co-culture of Scenedesmus obliquus and Rhodosporidium toruloides showed an increase in microalgae biomass by 20%; however, the FAME levels of 26% dw were not a significant increase, compared to monocultures. Both systems demonstrated that if one member of the assemblage is in dire stress, this stress will translate to the entire community. Characterisation of exopolymeric substances and metabolites provided a fuller picture on how these microorganisms co-exist. Additionally, a novel method, duo-plates, was developed and successfully tested to trap metabolites within co-cultures

Bio-oil Characterization via UV-Vis Spectroscopy: Phenols and Aromatic content

The Pacific Northwest National Laboratory is developing techniques to characterize (show what’s in it) bio-fuels. For bio-fuels to replace fossil fuels, full characterization is necessary for analyzing the pyrolysis product produced when you make bio-oil to determining quality of the fuel. In this work, we asked the question “can UV-Vis absorbance methods be used to characterize bio-oils.” To determine that we studied a direct method and a functionalized method to determine total aromatic and phenolic content. Preliminary results indicated that spectroscopic methods can be used to analyze bio-oils

2,7-Dibromo-9,9-dimethyl-9H-fluorene

The title mol­ecule, C15H15Br2, has crystallographic m2m site symmetry. As a result, all atoms, except for those of the methyl groups, are exactly coplanar. In the crystal structure, there are weak π–π inter­actions with a centroid–centroid distance of 3.8409 (15) Å between symmetry-related mol­ecules, which stack along the c axis

Co-culturing microbial consortia: approaches for applications in biomanufacturing and bioprocessing

The application of microbial co-cultures is now recognized in the fields of biotechnology, ecology, and medicine. Understanding the biological interactions that govern the association of microorganisms would shape the way in which artificial/synthetic co-cultures or consortia are developed. The ability to accurately predict and control cell-to-cell interactions fully would be a significant enabler in synthetic biology. Co-culturing method development holds the key to strategically engineer environments in which the co-cultured microorganism can be monitored. Various approaches have been employed which aim to emulate the natural environment and gain access to the untapped natural resources emerging from cross-talk between partners. Amongst these methods are the use of a communal liquid medium for growth, use of a solid–liquid interface, membrane separation, spatial separation, and use of microfluidics systems. Maximizing the information content of interactions monitored is one of the major challenges that needs to be addressed by these designs. This review critically evaluates the significance and drawbacks of the co-culturing approaches used to this day in biotechnological applications, relevant to biomanufacturing. It is recommended that experimental results for a co-cultured species should be validated with different co-culture approaches due to variations in interactions that could exist as a result of the culturing method selected

Initial Assessment of U.S. Refineries for Purposes of Potential Bio-Based Oil Insertions

This study examines how existing U.S. refining infrastructure matches in geography and processing capability with the needs projected from anticipated biofuels production. Key findings include: a potential shortfall in both overall hydrotreating capacity and hydrogen production capacity in refineries to manage the conversion of certain bio-derived feedstocks having high oxygen contents; a regional concentration of anticipated biofuel resources, placing added stress in particular refining regions (e.g. the Gulf Coast); uncertainties surrounding the impact of bio-derived fuel intermediates on the refiner’s ability to meet product performance and product quantity demands, and the need for better and more comprehensive chemical composition information; the need for considerably more data and experience on the behavior of projected biofuels feedstocks in refining processes (e.g. impacts on process performance and reliability); and the need to examine the optimum capital investment locations for additional processing equipment. For example, whether it is better to further refine biofuels at the new production sites, in centralized biofuel "depots", or whether the existing refining facilities should be expanded to better handle a more 'raw' biofuel

Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels: Fast Pyrolysis and Hydrotreating Bio-Oil Pathway

This report describes a proposed thermochemical process for converting biomass into liquid transportation fuels via fast pyrolysis followed by hydroprocessing of the condensed pyrolysis oil. As such, the analysis does not reflect the current state of commercially-available technology but includes advancements that are likely, and targeted to be achieved by 2017. The purpose of this study is to quantify the economic impact of individual conversion targets to allow a focused effort towards achieving cost reductions

Phosphorescent Organic Light-Emitting Devices: Working Principle and Iridium Based Emitter Materials

Even though organic light-emitting device (OLED) technology has evolved to a point where it is now an important competitor to liquid crystal displays (LCDs), further scientific efforts devoted to the design, engineering and fabrication of OLEDs are required for complete commercialization of this technology. Along these lines, the present work reviews the essentials of OLED technology putting special focus on the general working principle of single and multilayer OLEDs, fluorescent and phosphorescent emitter materials as well as transfer processes in host materials doped with phosphorescent dyes. Moreover, as a prototypical example of phosphorescent emitter materials, a brief discussion of homo- and heteroleptic iridium(III) complexes is enclosed concentrating on their synthesis, photophysical properties and approaches for realizing iridium based phosphorescent polymers