aaaaaThe Anton Paar DMA 4500 is a density meter which uses Anton Paar’s vibrating U-tube technology to provide a repeatability of 10 -5 g/cm 3. This instrument has an operating temperature range of 0 to 90 oC at atmospheric pressure.
aaaaaThe Anton Paar DMA HP is an accessory to the DMA 4500 allowing for high pressure (0 to 700 bar) and high temperature (-10 to 200 oC) density measurements of both liquids and gases.
aaaaaWater content of ionic liquids, or other liquids of interest, is measured using a Brinkmann Metrohm 756KF Karl Fisher Coulometer. The coulometer can measure as little as 1 mg of water accurately.
aaaaaViscosity measurements are performed with a Brookfield model DV-III Ultra Programmable (Cone and Plate) Rheometer equipped with a temperature bath. The samples are loaded using a glove box and kept under nitrogen to prevent the absorption of water from the atmosphere.
aaaaaMelting point temperatures, glass transition temperatures, and heat capacities of pure ionic liquids, mixtures, and pure compounds are measured on a Mettler-Toledo Differential Scanning Calorimeter (DSC), model DSC822 e. The Mettler Toledo STAR e Version 7.01 software is used to process the data. Sample sizes range from 25-40 mgs.
aaaaaDecomposition temperatures are measured with a Mettler Toledo TGA/SDTA 851e/SF/1100 ° C Thermal Gravimetric Analyzer. Different gases, such as nitrogen or air, can be used with the TGA under dynamic or static conditions.
aaaaaThe Kohn Apparatus is a stoichiometric phase equilibrium apparatus.  A known amount of gas is added to a high pressure cell with a known volume of liquid.  This equipment allows measurement of VLE and VLLE behavior.  Gas solubilities in ILs and IL/organic mixtures can be measured.  In addition, VLE, VLLE, and VLSE phase behavior can be observed.
aaaaaThe fixed volume high-pressure view cell, consists of an ISCO 260D syringe pump, stir plate, Heise pressure gauge, thermocouples and temperature controller, Valco sampling valves, Varian 3400 CX gas chromatrograph, and a cathetometer (Eberbach Corporation). The cell is made of SS316 and includes a borosilicate glass window to facilitate the observation of the cell contents. The window is sealed with graphoil gaskets. A specially designed Teflon ® stir bar extends the entire length of the cell to ensure good mixing of both phases. Valco sampling valves are used to analyze the liquid and vapor phases. The entire system is enclosed in an air bath to control the temperature at the desired value. If required, additional heat to the cell is provided using cartridge heaters. The temperature of the air bath and the cell are measured using type K thermocouples and controlled using temperature controllers (Omega Engineering MCS 6081-K, CS 6001-K). Carrier gas lines are heated to 170 °C using Thermolyne heating tape and the temperatures of the carrier gas line and the sampling valves are monitored using type K thermocouples and digital temperature indicators (Omega HH501DK, HH506 and 871A).
(1) CO 2 cylinder; (2) Syringe pump; (3) N 2 cylinder; (4) Equilibrium cell; (5) high-pressure side; (6) Piston; (7) System side; (8) Window; (9) Multiport sampling valves; (10) Magnetic stirrer; (11) Stir plate; (12) Air bath; (13) Fan; (14) Light bulb.
aaaaaThe variable volume view cell consists of a tubular reactor (HIP TOC7-20) modified at one end to accommodate a quartz window (Esco ZP612750). The cell contains a piston, which moves freely in the main body of the cell and separates the system side from the pressurization side. The window allows visual observation of the system side and N 2 is used as the pressurization fluid. Viton o-rings are used to obtain a pressure tight seal. CO 2 is added to the system using a syringe pump (Isco 260D). A type K thermocouple (Omega KMTSS-125-G-6) and Omega DP462 display meter are used to measure the temperature of the fluid in the cell. The system side is mixed with a magnetic stirrer (Cole Parmer). The cell is equipped with sampling ports to sample the vapor and liquid phases. The entire apparatus is placed in an air bath to control the temperature at the desired value. The temperature of the air bath is monitored and controlled (Omega CS 6071-APc temperature controlled) using a Pt RTD thermocouple and a 300 W light bulb as the heating source. The pressure of the contents on each side of the cell is monitored with a Serta 1505 pressure transducer equipped with a Cole-Parmer 94785-00 digital meter (pressurization side, + 0.8 bar) and a Heise Model 901 A digital pressure indicator (sample side, + 0.2 bar). Thermolyne heating tapes and fiberglass insulation tape are used to heat the sampling valves and the carrier gas lines to the GC at the temperature required to prevent condensation of the liquid.

(1) CO 2 cylinder; (2) Syringe pump; (3) N 2 cylinder; (4) Equilibrium cell; (5) high-pressure side; (6) Piston; (7) System side; (8) Window; (9) Multiport sampling valves; (10) Magnetic stirrer; (11) Stir plate; (12) Air bath; (13) Fan; (14) Light bulb.

aaaaaThis apparatus is used for separation of compounds based on their affinity for carbon dioxide at varying temperatures and pressures. The sample is loaded into the high pressure vessel, along with any cosolvents used to aid the compound - carbon dioxide affinity, and pressurized to a supercritical pressure of carbon dioxide at a given temperature. The mixture is stirred for eighteen hours. The release valve is heated to avoid the buildup of dry-ice due to Joule-Thompson cooling upon release. The vessel is slowly depressurized through the release valve and the supercritical carbon dioxide, now suspending the desired extracts, flows through the heated release valve, the warm water bath coil and into a chilled vial. The change in temperature and pressure significantly decreases the extract's affinity for the carbon dioxide. The extract is collected in the vial, while the carbon dioxide is released into the atmosphere.
aaaaaSamples of known composition are placed in 5 mL viewcells (3/8 in. o.d. Pyrex glass tubes) and heated in a water bath with a 1000 W immersion heater (Vycor 16790-1L) until the cloud point is exceeded. The samples are then cooled using a recirculating water chiller and an Omega CN 8500 temperature controller. The sample temperatures are measured by T-type thermocouples (Eurotherm 2408I temperature indicators). The temperature at which phase splitting occurs is noted.
aaaaaSimilarly to high performance liquid chromatography (HPLC) or gas chromatography (GC), a SFC can be used to separate components by their relative affinity to a mobile phase carrier and a stationary phase. SFC takes advantage of the unique supercritical properties of its mobile phase to generate fast (often under 10 minutes) and often complimentary separations. FID electrically detects the ions generated by the burning of solute at ppm resolution. It is good chromatographic detector for hydrocarbons and organics.
aaaaaThe Rubotherm is used to determine solubility or pure gases in ionic liquids. The Rubotherm is a magnetic suspension balance with a working range of high vacuum to 500 bar and -200ºC to 350ºC with a mass precision of 2 micrograms. The Balance records the weight change of the IL sapmpe upon gas absoroption. Since the balanance is magnetically coupled to the sorption cahmber, the microbalance itself is not exposed to the gas of interest. This allows the use of corrosive gases such as SO2 without harming the delicate microbalance.
aaaaaThe IGA (IGA 003, Hiden Analytical) is a gravimetric microbalance used to make vapor-liquid equilibrium measurements. The microbalance consists of a sample pan and counterweight symmetrically configured to minimize buoyancy effects. The balance has a 1 microgram stable resolution. Approximately 75 milligrams of ionic liquid sample are used for experiments. A diaphram pump (MZ 2d, Vacuubrand) and a turbomolecular pump (TMU 064, Pfeiffer) are used in conjunction with a water jacket connected to a constant-temperature bath (RTE-111, Neslab) to pressurize and heat the sample.
aaaaaThermo Cahn D200 microbalance is used to measure gas solubilities and gas diffusivities in ionic liquids and polymers at approximately 1 bar. The balance measures the weight gain in the sample due to the diffusion of gas into the IL or polymer.
aaaaaAs an analytical tool, the HPLC allows us to determine the composition of binary or ternary system in equilibrium. It utilizes a column (varies depending on the compounds) to separate the compounds present in a sample and then analyses then through a detector (UV Spectrometer). This allows us to measure ionic liquid concentrations as well as various other compounds present in our binary or ternary systems.