Carbohydrate Research Journal
Rhamnan and rhamnan sulfate are naturally occurring carbohydrates that have important biological functions and possible therapeutic applications, but studies are limited to the microheterogeneous mixtures from natural sources. This work reports the first synthesis of any sulfated rhamnan fragments and successful automation of the process with a recently developed automated solution-phase approach using N-iodosuccinimide/trimethylsilyl triflate (NIS/TMSOTf) promotor and levulinoyl ester deprotection conditions. The automated solution-phase activation/deprotection approach was initially able to create alpha 1 → 2, 1 → 3 type rhamnan di- and trisaccharide in moderate yields. Once these targets were achieved, a process to use SO3•pyridine complex in DMF for sulfation compatible with an automated solution-phase liquid handling system was developed and successfully applied to carbohydrate sulfation to create two rhamnan sulfate fragments with differing monosulfation patterns.
Catalysis Today Journal
A high-throughput (HT) methodology was applied for the synthesis, characterization and catalytic testing of silica and alumina supported Cu- and Ni-based catalysts for glucose hydrogenation. A design of Experiment (DoE) approach was also used in all steps. The deposition and reduction of both metals was performed using the chemical reduction with hydrazine method. In total, 36 catalysts were synthetized, characterized and tested in 5 days. The amount of metal deposited on the support was chosen as the discriminative and determining parameter. The catalysts were tested at low temperature (130 °C) in the hydrogenation of glucose to sorbitol. The results showed that the chemical reduction-precipitation method could be performed using fully automatized robots. The deposition of the metals strongly depended on the nature of the support, the temperature of the reduction and hydrazine/H2O ratio. The maximum metal precipitation occurred at higher temperature (70 °C) and lower N2H4/H2O ratio (0.04 mol/mol) in both cases. The results clearly showed that glucose conversion is higher for the catalysts synthesized at 70 °C compared to the catalysts synthesized at 50 °C, irrespective of the metal precursors, supports and hydrazine/water ratios employed during catalysts syntheses. With a total timespan of around 5 days we showed that HT methods applied to all the steps (synthesis, characterization and testing) can significantly reduce the time needed to develop a new catalytic process.
Chemical Science Journal
Porous liquids are an emerging class of materials and to date little is known about how to best design their properties. For example, bulky solvents are required that are size-excluded from the pores in the liquid, along with high concentrations of the porous component, but both of these factors may also contribute to higher viscosities, which are undesirable. Hence, the inherent multivariate nature of porous liquids makes them amenable to high-throughput optimisation strategies. Here we develop a high-throughput robotic workflow, encompassing the synthesis, characterisation and property testing of highly-soluble, vertex-disordered porous organic cages dissolved in a range of cavity-excluded solvents. As a result, we identified 29 cage–solvent combinations that combine both higher cage-cavity concentrations and more acceptable carrier solvents than the best previous examples. The most soluble materials gave three times the pore concentration of the best previously reported scrambled cage porous liquid, as demonstrated by increased gas uptake. We were also able to explore alternative methods for gas capture and release, including liberation of the gas by increasing the temperature. We also found that porous liquids can form gels at higher concentrations, trapping the gas in the pores, which could have potential applications in gas storage and transportation.
Royal Society of Chemistry Journal
We report on low molar mass cationic RAFT agents that provide predictable molar mass and low molar mass dispersities (Đm) in ab initio emulsion polymerization. Thus RAFT emulsion polymerization of styrene in the presence of the protonated RAFT agent, ((((cyanomethyl)thio)carbonothioyl)(methyl)amino)pyridin-1-ium toluenesulfonate (4), and the analogous methyl-quaternized RAFT agents, 4-((((cyanomethyl)thio)carbonothioyl)(methyl)amino)-1-methylpyridin-1-ium dodecyl sulfate (6), provide low dispersity polystyrene with Đm 1.2–1.4 for Mn ∼ 20 000. We postulate that the success of ab initio emulsion polymerization with 4 is due to the hydrophilicity of the pyridinium group, which is such that the water soluble RAFT agent partitions predominantly into the aqueous phase under the conditions of the experiment and that 4 provides little retardation. With 6, when the counterion is dodecyl sulfate, we can achieve “surfactant-free” RAFT emulsion polymerization to provide a low Đm polystyrene. However, the RAFT end-group is lost on isolation of the polymer. Preliminary results show that this class of RAFT agent is broadly applicable in ab initio emulsion polymerization of other more-activated monomers (e.g., butyl acrylate, butyl methacrylate). Furthermore, cyanomethyl(pyridin-4-yl)carbamodithioate (3, the RAFT agent in neutral form) provides molar mass control and Đm < 1.8 in ab initio emulsion polymerization of less activated monomers, specifically, the vinyl esters, vinyl acetate and vinyl benzoate.
Watch this inspiring video:
For more information about the solution applied:
For details please contact [email protected]
Advances in Polymer Technology Journal
Poly(methyl methacrylate-block-styrene) block copolymers (BCs) of low dispersity were selectively sulfonated on the styrenic segment. Several combinations of degree of polymerization and volume fraction of each block were investigated to access different self-assembled morphologies. Thin films of the sulfonated block copolymers were prepared by spin-coating and exposed to solvent vapor (SVA) or thermal annealing (TA) to reach equilibrium morphologies. Atomic force microscopy (AFM) was employed for characterizing the films, which exhibited a variety of nanometric equilibrium and nonequilibrium morphologies. Highly sulfonated samples revealed the formation of a honeycomb-like morphology obtained in solution rather than by the self-assembly of the BC in the solid state. The described morphologies may be employed in applications such as templates for nanomanufacturing and as cover and binder of catalytic particles in fuel cells.
Pure and Applied Chemistry Journal
Carbohydrate structures are often complex. Unfortunately, synthesis of the range of sugar combinations precludes the use of a single coupling protocol or set of reagents. Adapting known, reliable bench-chemistry reactions to work via automation will help forward the goal of synthesizing a broad range of glycans. Herein, the preparation of di- and tri-saccharides of alpha 1→2 rhamnan fragments is demonstrated using thioglycoside donors with the development for a solution-phase-based automation platform of commonly used activation conditions using N-iodosuccinimide (NIS) with trimethylsilyl triflate. Byproducts of the glycosylation reaction are shown to be compatible with hydrazine-based deprotection conditions, lending broader functionality to this method as only one fluorous-solid-phase extraction step per coupling/deprotection cycle is required.
CM Chemistry of Materials Journal
A structurally diverse family of 39 covalent triazine-based framework materials (CTFs) is synthesized by Suzuki-Miyaura polycondensation and tested as hydrogen evolution photocatalysts using a high-throughput workflow. The two best-performing CTFs are based on benzonitrile and dibenzo[b,d]thiophene sulfone linkers, respectively, with catalytic activities that are among the highest for this material class. The activities of the different CTFs are rationalized in terms of four variables: the predicted electron affinity, the predicted ionization potential, the optical gap, and the dispersibility of the CTFs particles in solution, as measured by optical transmittance. The electron affinity and dispersibility in solution are the best predictors of photocatalytic hydrogen evolution activity.
September 2019 – Agrate Brianza, Italy / Füllinsdorf, Switzerland
The Italian Group Intercos, a global leader in color cosmetics, has decided to partner with Chemspeed Technologies to accelerate and enhance the research of novel cosmetic formulations and the corresponding color development and prototyping.
Cosmetic formulations are quickly growing in complexity: changing ingredient regulations, increased environmental awareness, evolving cosmetic trends and curiosity for new color matches are just a few of the drivers giving a hard time to scientists.
Automation and digitalization methodologies represent a revolutionary approach to widely explore ingredient and process variables and accelerate the development of new products. Chemspeed’s formulation workstation, called “FORMAX”, is the first fully automated and integrated formulation and characterization solution for the personal care industry. A large number of automated formulations (from 3 to 36 depending on configuration) can be prepared contemporaneously while screening several parameters: ingredients, concentrations, amounts, color to matrix ratio, temperature, pH, viscosity and much more.
FORMAX key to success include precise gravimetric dispensing of ingredients (including solids and highly-viscous liquids), preparation of phases at different mixing speeds and temperatures (including ingredient addition while stirring/heating), formulation characterization (viscosity, pH, …) at any time during the experiment, ready to use samples for testing, color prototyping, etc. The experimental results (successes and failures) are used to rank each formulation and make it repeatable at any time. After this ranking, a set of new conditions can be generated and run experimentally using FORMAX. This process can continue until the best product or color is identified.
Intercos scientists mentioned: “Lamination is performed directly in the formulation vessel. This avoids messy and time-consuming color preparation steps and enables color adjustments at any time. This, together with the contemporaneous formulation of multiple recipes per cycle, grants a much shorter time to sample.”
High-throughput methodologies represent an effective approach to accelerate battery development. With an almost unlimited range of raw material and process variables to evaluate, very short time-to market milestones and incumbent technologies in the view, scientists in battery research manage to stay ahead of the curve thanks to Chemspeed’s innovative solutions.