Solvent-based Methods Research Articles

Current Progress and Future Directions in Gas‐Phase Metal‐Organic Framework Thin‐Film Growth

Deposition of materials as a thin film is important for various applications, such as sensors, microelectronic devices, and membranes. There have been breakthroughs in gas-phase metal-organic framework (MOF) thin-film growth, which is more applicable to micro- and nanofabrication processes and also less harmful to the environment than solvent-based methods. Three different types of gas-phase MOF thin film deposition methods have been developed using chemical vapor deposition (CVD), atomic layer deposition (ALD), and physical vapor deposition (PVD)-CVD combined techniques. The CVD-based method basically converts metal oxide layers into MOF thin films by exposing the surface to ligand vapor. The ALD-based method allows growing MOF thin films following layer-by-layer (LBL) growth by sequentially exposing gas-phase metal and ligand precursors. The PVD-CVD method uses PVD for metal deposition and CVD for ligand deposition, which is similar to LBL growth. These gas-phase growth methods can broaden the use of MOFs in diverse areas. Herein, the current progress of gas-phase MOF thin film growth is discussed and future directions suggested.

Polyetheresterurethane Based Porous Scaffolds with Tailorable Architectures by Supercritical CO2 Foaming

Porous three-dimensional (3D) scaffolds are promising treatment options in regenerative medicine. Supercritical and dense-phase fluid technologies provide an attractive alternative to solvent-based scaffold fabrication methods. In this work, we report on the fabrication of poly-etheresterurethane (PPDO-PCL) based porous scaffolds with tailorable pore size, porosity, and pore interconnectivity by using supercritical CO2 (scCO2) fluid-foaming. The influence of the processing parameters such as soaking time, soaking temperature and depressurization on porosity, pore size, and interconnectivity of the foams were investigated. The average pore diameter could be varied between 100-800 μm along with a porosity in the range from (19 ± 3 to 61 ± 6)% and interconnectivity of up to 82%. To demonstrate their applicability as scaffold materials, selected foams were sterilized via ethylene oxide sterilization. They showed negligible cytotoxicity in tests according to DIN EN ISO 10993-5 and 10993-12 using L929 cells. The study demonstrated that the pore size, porosity and the interconnectivity of this multi-phase semicrystalline polymer could be tailored by careful control of the processing parameters during the scCO2 foaming process. In this way, PPDO-PCL scaffolds with high porosity and interconnectivity are potential candidate materials for regenerative treatment options.

Established and advanced approaches for recovery of microbial polyhydroxyalkanoate (PHA) biopolyesters from surrounding microbial biomass

Abstract Downstream processing for recovery of microbial polyhydroxyalkanoate (PHA) biopolyesters from biomass constitutes an integral part of the entire PHA production chain; beside the feedstocks used for cultivation of PHA-production strains, this process is currently considered the major cost factor for PHA production. Besides economic aspects, PHA recovery techniques need to be sustainable by avoiding excessive use of (often precarious!) solvents, other hazardous chemicals, non-recyclable compounds, and energy. Moreover, the applied PHA recovery method is decisive for the molecular mass and purity of the obtained product, and the achievable recovery yield. In addition to the applied method, also the PHA content in biomass is decisive for the feasibility of a selected technique. Further, not all investigated recovery techniques are applicable for all types of PHA (crystalline versus amorphous PHA) and all PHA-producing microorganisms (robust versus fragile cell structures). The present review shines a light on benefits and shortcomings of established solvent-based, chemical, enzymatic, and mechanical methods for PHA recovery. Focus is dedicated on innovative, novel recovery strategies, encompassing the use of “green” solvents, application of classical “PHA anti-solvents” under pressurized conditions, ionic liquids, supercritical solvents, hypotonic cell disintegration for release of PHA granules, switchable anionic surfactants, and even digestion of non-PHA biomass by animals. The different established and novel techniques are compared in terms of PHA recovery yield, product purity, impact on PHA molar mass, scalability to industrial plants, and demand for chemicals, energy, and time.

Polymorphous Indium Metal-Organic Frameworks Based on a Ferrocene Linker: Redox Activity, Porosity, and Structural Diversity.

The metallocene-based linker molecule 1,1'-ferrocenedicarboxylic acid (H2FcDC) was used to synthesize four different polymorphs of composition [In(OH)(FeC12H8O4)]. Using conventional solvent-based synthesis methods and varying the synthetic parameters such as metal source, reaction temperature, and solvent, two different MOFs and one 1D-coordination polymer denoted as CAU-43 (1), In-MIL-53-FcDC_a (2), and In-FcDC (3) were obtained. Furthermore, thermal treatment of CAU-43 (1) at 190 °C under vacuum yielded a new polymorph of 2, In-MIL-53-FcDC_b (4). Both MOFs 2 and 4 crystallize in a MIL-53 type structure, but in different space groups C2/m for 2 and P1̅ for 4. The structures of the four title compounds were determined by single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), or a combination of three-dimensional electron diffraction measurements (3D ED) and PXRD. N2 sorption experiments of 1, 2, and 4 showed specific surface areas of 355 m2 g-1, 110 m2 g-1, and 140 m2 g-1, respectively. Furthermore, the electronic properties of the title compounds were characterized via Mössbauer and EPR spectroscopy. All Mössbauer spectra showed the characteristic doublet, proving the persistence of the ferrocene moiety. In the cases of 1, 3, and 4, appreciable impurities of ferrocenium ions could be detected by electron paramagnetic resonance spectroscopy. Cyclovoltammetric experiments were performed to demonstrate the accessible redox activity of the linker molecule of the title compounds. A redox process of FcDC2- with oxidation (between 0.86 and 0.97 V) and reduction wave (between 0.69 and 0.80 V) was observed.

Investigation of Mechanisms for Gravity Drainage of Heavy Oil and Solvent Mixtures in a Hele-Shaw Cell

One reason it is challenging to predict oil recovery rates from solvent-based heavy oil recovery methods is that the interplay of the mass transfer and convective flow mechanisms is not well unders...

Measurements and NRTL modeling of liquid-liquid equilibrium of dimethyl ether/bitumen

Solvent-aided or solvent-based heavy oil recovery methods have shown to be promising alternatives to the conventional thermal methods. Recently, dimethyl ether (DME) has been suggested as a potential candidate for solvent-aided recovery processes. Liquid-liquid equilibrium (LLE) of the DME/bitumen is essential for the design and optimization of the oil recovery. While vapor-liquid equilibrium (VLE) data of DME/bitumen have been reported in the literature, LLE data and predictive models for DME/bitumen are lacking. In this work, LLE measurements of DME/bitumen mixtures were conducted. Equilibrium composition of DME, density, and viscosity of the light phase as well as saturation pressures of the mixture were measured. Compositional analysis of the heavy and light cuts was determined by coupling Simulated Distillation (SD) and Gel Permeation Chromatography (GPC). Based on the compositional analysis, bitumen was divided into two pseudocomponents and LL K-values of the components in equilibrium were calculated. Non-Random Two Liquid (NRTL) model was calibrated to represent the experimental compositional data and K-values. AARD of the model predictions was found to be less than 6.5%. The results presented in this work provide new insight into in-situ upgrading of bitumen and enable better design and optimization of the solvent-aided oil recovery processes.

Challenges in developing polymer flocculants to improve bitumen quality in non-aqueous extraction processes: an experimental study

Western Canada’s oil sands hold the third-largest hydrocarbon deposits in the world. Bitumen, a very heavy petroleum, is currently recovered by surface mining with warm water or in situ. Recovery processes that use organic solvents are being developed to reduce water usage and tailings production. While solvent-based methods can effectively extract bitumen, removal of residual fine solids from diluted bitumen product (DBP) to meet the pipeline transport requirement of < 0.5 wt% solids and water in DBP remains a major challenge. We propose a novel area of application of polymer flocculants for fine solids removal from DBP. In principle, polymer flocculants can be applied to help remove these residual solids in conjunction with physical separation processes to increase process effectiveness and energy efficiency. Several polymers are selected and screened for flocculation behavior using kaolinite suspended in DBP and toluene, as a model system. Focused beam reflectance measurements and force tensiometer techniques are used to determine flocculation and sedimentation in DBP. The observed flocculation and sedimentation rate enhancements indicate that the polymers tested have only minor effects, providing opportunities for advanced polymer development. These findings exemplify the challenges in identifying polymers that may be effective as flocculants in heavy petroleum media.

Greener Dye Synthesis: Continuous, Solvent-Free Synthesis of Commodity Perylene Diimides by Twin-Screw Extrusion.

A continuous, scalable, and solvent-free method for the synthesis of various naphthalic imides and perylene diimides (PDIs) using twin-screw extrusion (TSE) is reported. Using TSE, naphthalic imides were obtained quantitatively without the need for excess amine reactant or product purification. With good functional-group tolerance, alkyl and benzyl amine derived PDIs (incl. commercial dyes) were obtained in 50-99 % yield. Use of K2 CO3 , enabled synthesis of more difficult aniline-derived PDIs. Furthermore, an automated continuous TSE process for Pigments Black 31 and 32 is demonstrated, with a throughput rate of about 1500 g day-1 , corresponding to a space time yield of about 30×103 kg m-3 day-1 , which is 1-2 orders of magnitude greater than for solvent-based batch methods. These methods provide substantial waste reductions and improved efficiency compared to conventional solvent-based methods.

Analysis of oxidative stress in immune cells

Reactive oxygen species (ROS) is produced in immune cells during immune responses and is necessary for host defense and inflammation. Furthermore, ROS acts as signals for gene expression and is required for T cell proliferation and activation. While low levels of ROS play important roles in cell activation, high levels of ROS induce significant damage to cells. To monitor redox state in living cells we generated transgenic mice expressing a green fluorescent protein (roGFP) whose fluorescence varies with redox state (J Invest Dermatol. 34, 1701-1709, 2014). Since the redox state may change during in vitro analysis it should be necessary to fix the cells. Here we evaluate the fixation methods to analyze redox state in vitro. We compared aldehyde and organic solvent-based fixation methods. To fix redox state of roGFP protein N-ethylmaleimide which react thiol and modify cysteine residues in protein was used. Splenocytes were isolated from roGFP mice and treated with hydrogen peroxide (oxidized state) or DTT (reduced state) to induce the maximum oxidation and reduction status. Oxidized or reduced cells fixed with various fixation methods were accessed by flow cytometry. Organic solvents lead to a severe loss of fluorescence of roGFP protein. On the other hand, fixation with aldehyde and N-ethylmaleimide was useful to maintain fluorescence and redox status of roGFP. This system should be a powerful and convenient tool for analyzing redox state in various types of immune cells in vitro.

Mechanochemical synthesis of (hetero)aryl Au(i) complexes

Shake, Rattle and Gold! Mechanochemistry enables the efficient and selective synthesis of organo-Au(i) complexes.

A Novel Rheological Method to Assess Drug-Polymer Interactions Regarding Miscibility and Crystallization of Drug in Amorphous Solid Dispersions for Oral Drug Delivery.

Solid dispersions provide a key technology to formulate poorly water-soluble drugs, and a main task of early development is appropriate selection of polymer. This study investigates the use of a novel rheology-based approach to evaluate miscibility and interactions of drugs with polymers regarding amorphous solid drug dispersions for oral administration. Tacrolimus was used as model drug and hydroxypropyl cellulose, ethylcellulose, Soluplus®, polyethyleneglycol 6000, Poloxamer-188 (Koliphor-188), and Eudragit® S100 were used as excipients. Solvent-based evaporation methods were used to prepare binary solid dispersions of drug and polymer. Data of the dilute solution viscosimetry were compared with in silico calculations of the Hansen solubility parameter (HSP), as well as phase separation/crystallization data obtained from X-ray diffraction and differential scanning calorimetry. HSP calculations in some cases led to false positive predictions of tacrolimus miscibility with the tested polymers. The novel rheology-based method provided valuable insights into drug-polymer interactions and likely miscibility with polymer. It is a rather fast, inexpensive, and robust analytical approach, which could be used complementary to in silico-based evaluation of polymers in early formulation development, especially in cases of rather large active pharmaceutical ingredients.

Ekstraksi Polifenol Total dari Umbi Bawang Dayak (Eleutherine bulbosa [Mill.] Urb.) Menggunakan Metode Citric Acid-Glucose based Microwave Assisted Extraction

The use of environmentally friendly solvent-based expulsion methods today began to be widely used, one of which is a microwave-assisted extraction (MAE) using a citric acid-glucose acid solvent. The study aims to determine the influence of the use of citric acid-glucose based microwave-assisted extraction against the total extraction of polyphenols from Dayak onion bulbs (Eleutherine bulbosa [Mill.] Urb.).The dried samples were extracted using a solvent (green solvent) citric acid – glucose with a ratio of 4:1, 5:1 and 6:1 g/g with the extraction conditions in the form of microwave strength of 50% for 10 minutes with a sample and solvent ratio of 1:10 g/mL, then Extract solution obtained further determination of the total levels of polyphenols using Folin ciocalteu reagents, and its absorption was measured using a UV-vis spectrophotometer at a wavelength of 791 nm. Based on the results of the study, the total amount of polyphenols obtained from each of the solvent conditions used against the samples was 21.92 mgGAE/g samples, 13.86 mgGAE/g samples, and 14.38 mgGAE/g samples. From this study, it can be concluded that the concentration of citric acid in the microwave-based citric acid-glucose method is assisted by extraction according to the ability of the solvent in the competency of polyphenols from Dayak onion bulbs.

Thermoplastic electroactive gels for 3D-printable artificial muscles

3D-printable artificial muscles have only recently garnered interest, and few 3D-printed artificial muscles have been demonstrated. In this article, we introduce the concept of thermoplastic electroactive gels, new smart materials that can be fabricated simply and rapidly by heating, overcoming the limitations of previous dangerous and time-consuming solvent-based manufacturing methods, and enabling hot-pressing, melt-recycling, extrusion and 3D-printing. We present and characterise a new example material, PVC-DIDA (polyvinyl chloride and diisodecyl adipate) gel and demonstrate multi-layer PVC-DIDA gel artificial muscles. Finally, the extrudability of PVC-DIDA gel is confirmed, and an artificial muscle made from extruded electroactive gel is presented. The electroactivity and extrudability of these thermoplastic gels highlights them as excellent candidate materials for 3D-printing artificial muscle structures.

Solvent-free Methods for Co-crystal Synthesis: A Review.

Pharmaceutical co-crystals are the homogeneous crystalline substances composed of two or more substances bound together in the same crystal lattice via noncovalent interactions like hydrogenbonding, electrostatic interaction and Vander Waals interactions. Currently, co-crystals provide excellent opportunities to the formulation scientists in developing new pharmaceutical products by improving the pharmaceutically significant properties like solubility, dissolution rate, bioavailability, stability, and some other derived properties. Due to their ability to improve pharmacokinetic performance and their important intellectual property status, co-crystals are likely to have a very significant role in future drug development. Thus, formulation scientists have their focus on the development aspects of a co-crystallization process that include a rational selection of co-former, the discovery of novel synthetic procedures and new characterization techniques, and large scale production of these novel materials. The objective of this article is to present an extensive review of solvent-free methods for co-crystal synthesis, mainly focusing on the principle mechanisms, advantages, and drawbacks of each method. From the review of the topic, it is clear that the solvent-free methods can offer numerous advantages over solvent-based methods in the design and the production of co-crystals of pharmaceutical use and these methodologies can also pave the path to advancing the field of co-crystal synthesis. Some of the advantages accompanied with solvent-free methods are the use of no or very less amount of solvent(s), exceptional purity and quality of produced co-crystal, large scale production and the short reaction times in few cases.

Radiation Curing and Its Application in Li Cells

Li-ion battery composite electrodes consist of three components including active materials, conductive additives and polymer binders. Conventionally, the electrodes are manufactured through a slurry-based process using polymer binder, typically polyvinylidene difluoride (PVDF) that is dissolved in organic solvent, N-Methyl-2-pyrrolidone (NMP). A powder mixture of active materials and carbon black is added to the solution to form a slurry, which is coated onto a current collector (i.e. aluminum foil) and then passed through drying ovens to evaporatethe NMP. Several drawbacks have been identified using the conventional manufacturing method.1–4 These processes require high energy consumption from electrode drying, a large equipment footprint, low production speed and mandatory solvent recovery, which results in a significant portion of battery cell and battery plant cost. It has been calculated that the total electrode manufacturing costs can contribute about 8-9% of the total pack cost.1 Alternative processing methods of electrode coatings are being sought for faster production and lower cost. Radiation-based curing has been developed to replace the solvent-based methods in certain sectors of the coating industry.5 The former offers significant process energy savings, is ultra-high speed, and utilizes much more compact equipment than conventional drying ovens (much less plant floor space required). Radiation curing employs ultraviolet (UV) light or an electron beam (EB) as the energy source to chemically polymerize and crosslink small molecules (i.e. monomers or oligomers) into high molecular weight (MW) crosslinked polymers. Therefore, a minimal amount or even no volatile organic compounds (VOCs) are required during the coating formulation and deposition. Both UV and EB cured Li-ion battery cathodes have been reported to have good performance in lab coin cells.6,7 However, the penetration of UV is limited by its low energy and the black solid powders (active material and carbon black) further decrease the curing efficiency due to blockage of the UV light. The UV cured electrode loading is 6 mg/cm2,6 which is significantly lower than EB cured electrodes.7 The penetration of EB radiation is related to the applied accelerating voltage, which means 25 mg/cm2 (~ 4mAh/cm2) loading can be easily cured with EB equipment operating at 250 keV. Given the Li-ion battery industry is seeking even higher areal loadings to achieve higher energy density,8–10 EB curing is likely more suitable for electrode processing compared to UV curing. Based on decades of development and commercial deployment, self-shielded EB machines routinely operate with high reliability and low maintenance in industrial roll-to-roll production environments. In this study, we report the scale-up of high speed EB curing for processing thick battery electrodes with EB-curable acrylate binders. High speed EB curing at a 500 feet-per-minute (fpm) line speed were successfully applied to thick cathodes (25 mg/cm2). The performance of the EB cured cathodes were evaluated in 1.5 Ah pouch cells.

Viscous oil recovery and in-situ deasphalting in fractured reservoirs – Part 2: Effect of solvent type and temperature

This paper advances the understanding of the solvent-based EOR methods from our previous work by investigating the effect of solvent type and temperature on the recovery of viscous oil by liquid extraction using sandstone cores with an artificial fracture. The production mechanisms were identified through the analysis of oil production rate, ultimate recovery, and in-situ deasphalting in different sections of the core. The use of dichloromethane (DCM) was introduced as the reference to study the production without in-situ deasphalting whereas n-pentane injection was compared to that of n-butane injection to study the effect of paraffin length on production with in-situ deasphalting. Sustained high production rates, which deviate from the behavior of typical gravity drainage processes, were observed in the cases with in-situ deasphalting. This discrepancy was attributed to the enhanced convection in the matrix due to the alteration of fracture aperture by asphaltene precipitation and deposition. Temperature has a significant impact on oil production through its effect on mass diffusivity as well as asphaltene rheology. The result of this work indicates that solvent selection is a key factor in the optimizing solvent EOR process and potential asphaltene deposition should be taken into consideration.

M. Concepción Gimeno

Angewandte Chemie International EditionVolume 58, Issue 32 p. 10790-10790 Author ProfileFree Access M. Concepción Gimeno First published: 22 February 2019 https://doi.org/10.1002/anie.201901959AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract “If I could have dinner with three famous scientists from history, they would be Marie Curie, Albert Einstein, and Rosalind Franklin. And I would ask them how was research and life being a scientist in their time …” Find out more about M. Concepción Gimeno in her Author Profile. M. Concepción Gimeno The author presented on this page has recently been named one of the IUPAC Distinguished Women in Chemistry and Chemical Engineering. Her latest contribution to Angewandte Chemie was: “Synthesis of Gold–Silver Luminescent Honeycomb Aggregates by Both Solvent-Based and Solvent-Free Methods”: M. C. Blanco, J. Cámara, M. C. Gimeno, A. Laguna, S. L. James, M. C. Lagunas, M. D. Villacampa, Angew. Chem. Int. Ed. 2012, 51, 9777; Angew. Chem. 2012, 124, 9915. Date of birth: December 7, 1962 Position: Professor, University of Zaragoza E-mail: gimeno@unizar.es Homepage: http://conchita-gimeno.webs.com/ ORCID: 0000-0003-0553-0695 Education: 1985 Degree in Chemistry, University of Zaragoza 1988 PhD in Chemistry, Prof. Rafael Usón and Prof. Antonio Laguna, University of Zaragoza 1988–1989 Postdoctoral position, Prof. F. Gordon A. Stone, University of Bristol Awards: 2017 IUPAC Distinguished Women in Chemistry Award; 2017 Excellence in Organometallic Chemistry Research Award in Spain (Spanish Royal Society of Chemistry); 2017 Best Research Group Award (Research and Future, Aragón, Spain); 2018 Medal of the Aragón Government Courts; 2018 Excellence in Research Award of the Spanish Royal Society of Chemistry Research: Synthesis of group 11 metal complexes and their use as luminescent materials, in catalysis, or in drug design Hobbies: Reading, travelling, music If I could have dinner with three famous scientists from history, they would be Marie Curie, Albert Einstein, and Rosalind Franklin. And I would ask them how was research and life being a scientist in their time. If I were not a scientist, I would be a writer. I chose chemistry as a career because I was very interested in mixing substances and see what happened. My biggest motivation is to discover new compounds with real applications. I would have liked to have discovered the use of immunotherapy for cancer treatment. The most important thing I learned from my parents is the importance of small things and the effort needed to achieve your dreams. If I won the lottery, I would do a long journey around the world. My favorite place on earth is Qaleraliq glacier in Greenland (with superb Northern Lights). I can never resist a good meal in good company. My favorite food is seafood paella; I always miss it when I am away from Spain. My favorite author (fiction) is Gabriel García Marquez, among others. My top three films of all time are The Godfather, Casablanca, All about Eve, and many others. My favorite piece of music is Adagio in G Minor by Tomaso Albinoni. My 5 top papers: 1“Axially Chiral Allenyl Gold Complexes”: A. Johnson, A. Laguna, M. C. Gimeno, J. Am. Chem. Soc. 2014 , 136, 12812. (Allenyl gold complexes are important organogold complexes relevant to intermediate catalytic gold species). 2“Luminescent Re(i) and Re(i)/Au(i) complexes as cooperative partners in cell imaging and cancer therapy”: V. Fernández-Moreira, I. Marzo, M. C. Gimeno, Chem. Sci. 2014 , 5, 4434. (Theranostic probes based on two different metal fragments to provide emissive properties in one side and biological activity in the other). 3“N-Heterocyclic Carbene Ligands as Modulators of Luminescence in Three-Coordinate Gold(I) Complexes with Spectacular Quantum Yields”: R. Visbal, I. Ospino, J. M. López de Luzuriaga, A. Laguna, M. C. Gimeno, J. Am. Chem. Soc. 2013 , 135, 4712. (Compounds with excellent photophysical properties, suitable for use as dopants in OLEDs). 4“Intensely Luminescent Gold(I)–Silver(I) Cluster Complexes with Tunable Structural Features”: Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deeton, C. Tang, H.-J. Gysling, M. C. Gimeno, C. Larraz, M. D. Villacampa, A. Laguna, R. Eisenberg, J. Am. Chem. Soc. 2004 , 126, 9488. (Luminescent gold–silver clusters with a broad scope of color tunability). 5“Aurophilicity at Sulfur Centers: Synthesis and Structure of the Tetragold(I) species [(Ph3PAu)4S](CF3SO3)2⋅2 CH2Cl2”: F. Canales, M. C. Gimeno, P. G. Jones, A. Laguna, Angew. Chem. Int. Ed. Engl. 1994, 33, 769; Angew. Chem. 1994, 106, 811. (Electron-deficient gold complexes stabilized by aurophilic interactions). Volume58, Issue32August 5, 2019Pages 10790-10790 ReferencesRelatedInformation

(Invited) Dry Process for the Preparation of Porous Composite Electrodes for Battery Application

The development of advanced Li-ion battery would require innovative approaches to improve the present performances, while lowering the environmental footprint and price of their fabrication. In this scope, we are currently carrying out different projects to consider the electrode materials as well the process to make the batteries. This presentation will focus on the second aspects, which concerns the development of a solvent-free process to make composite electrodes using an owned patented process by Hutchinson [1]. Currently, most of the electrode fabrication involves the use of organic solvent (typically N-methyl-2-pyrrolidone, NMP, which is toxic). Life cycle analysis studies of the LiB manufacturing process showed that this type of electrode preparation accounts for a significant portion of their overall environmental imprint [2]. While the use of water, instead of NMP, would be preferable to minimize this impact [3], a solvent-free electrode manufacturing consumes less energy in comparison to solvent-based methods [4]. Different electrode formulations were prepared by the dry process. The mechanical, electrical and electrochemical properties in half cells were assessed and compared to composite electrodes obtained by doctor blade coating using the classical PVdF binder. The different steps of the dry process (mixing, lamination and adhesion to current collectors) were studied and optimized separately to reach the maximum loading, while ensuring good power performances. The Ragone plots for each electrode, tested in half cells, were evaluated and the best formulation was retained for the full cell manufacture. The performances of LiFePO4/Li4Ti5O12 batteries are comparable to our best electrodes made with PVdF. The different aspects of the process will be discussed in this presentation.

DINUCLEAR COPPER(II) ACETATE COMPLEX WITH CAFFEINE, A FAST MECHANOCHEMICAL SYNTHESIS

A new dinuclear paddle-wheel copper(II) complex with caffeine was synthesized by the solvent-based and mechanochemical methods from copper(II) acetate and caffeine in a 1:1 molar ratio. Mechanochemical synthesis was found to be the fastest and easiest way to prepare the complex. The reaction proceeds with addition of small amounts of methanol or ethanol. The complex was characterized by FT-IR spectroscopy, elemental and thermoanalytical methods (TG and DSC) and X-ray diffraction methods. The molecular and crystal structure was determined by the single crystal X-ray diffraction method. The complex molecule consists of a centrosymmetric dinuclear unit, Cu2(-Ac)4(caf)2, with two copper(II) atoms bridged by four acetato groups, and N-coordinated caffeine (caf) molecules in the apical posi-tions.

Microfluidic platform to evaluate asphaltene deposition during solvent-based extraction of bitumen

Viscosity reduction is necessary for economical heavy oil production. Dilution of heavy oil with light hydrocarbons is one of the extraction methods as an alternative to the thermal processes. However, in-situ upgrading of heavy oil leads to asphaltene deposition, which causes pore clogging and prevents diluted oil to drain in the direction of production well. Understanding the asphaltene precipitation and deposition mechanism on hydrophilic and hydrophobic porous media improves the efficiency of the solvent-based extraction methods and accuracy of solvent selection in both experiment and simulation. In this work, two different patterns of microfluidic platforms were used to study asphaltene deposition in porous media. Porous media were treated with a silane to evaluate the effect of wettability alteration on asphaltene deposition. Quantitative analysis of the detection point of asphaltene deposition showed faster precipitation from n-pentane in comparison with n-decane as heavier solvent. Helium Ion Microscopy (HIM) analysis was performed on precipitated asphaltene to evaluate the effect of different solvents on the structure of asphaltene precipitates. Moreover, a high-resolution Total Internal Reflection Fluorescence (TIRF) microscopy was used to identify the morphology of precipitated asphaltenes and results compared with HIM analysis. It was found that precipitated asphaltene with n-decane had larger asphaltene particles but fine precipitates from n-pentane led to higher aggregation and flocculation. Formation damage and pore blockage of deposited asphaltene from n-pentane was noticeably higher than n-decane.