News Article | August 24, 2016
Soft controllers are fabricated from Sylgard 184 PDMS (Dow Corning Corp.) using soft lithography moulding and bonding techniques. First, a mould was fabricated on a silicon wafer using SU-8 negative photoresist (Microchem Corp.). SU-8 3050 photoresist was used to achieve 100-μm film thickness. Baking, exposing and developing steps were performed in accordance with product specifications in the product datasheet. The completed wafer is placed in a Petri dish to form a competed mould assembly. Soft controllers consist of an upper mould, a lower mould and an intermediate thin film. The upper and lower moulds are made on one wafer to ease fabrication. PDMS is poured into the mould assembly to a height of 1 mm. Separately, PDMS is spin-coated onto a wafer at 1,500 r.p.m. for 60 s for a film thickness of 35 μm. After curing at 90 °C for 20 min, PDMS forms are removed from the moulds and holes are punched at all inlets and outlets. The upper layer is bonded to the wafer-adhered thin film after exposing to oxygen plasma at 35 W for 20 s in a Deiner Pico plasma system (Deiner Electronic GmbH). Holes are punched in the thin film, masks are placed as described in ref. 25, and the lower layer is bonded to the thin film using the plasma recipe above. Two inks—a ‘fugitive ink’ and a ‘catalytic ink’—are formulated for EMB3D printing. The fugitive ink is prepared by adding 27 wt% gel of Pluronic F127 to ice-cold, deionized, ultra-filtrated (DIUF) water, followed by mixing in a planetary mixer for 5 min at 2,000 r.p.m., and storing at 4 °C. The fugitive ink is not used until the Pluronic F127 completely dissolves in solution. The ink is prepared for printing by loading the solution at 4 °C in a 3-cm3 syringe barrel (EFD Nordson) and centrifuged at 3,000 r.p.m. for 5 min to degas. For EMB3D printing, the barrel of the fugitive ink is fitted with a stainless steel nozzle (0.15-mm inner diameter; EFD Nordson). The catalytic ink is prepared by first synthesizing and then dissolving a diacrylated Pluronic (F127-DA) at 30 wt% concentration with a solution of Irgacure 2959 (at 0.5 wt%, BASF) in DIUF water at 4 °C. The F127-DA is synthesized under an inert nitrogen atmosphere by first adding 400 ml of dry toluene (Sigma-Aldrich Co.) to a three-neck flask fixed to a condenser with circulating cold water and magnetically stirred at 300 r.p.m. 70 g of Pluronic F127 (Sigma-Aldrich Co.) is then dissolved in the toluene after heating the solvent to 60 °C. After the solution is allowed to cool to room temperature, triethylamine (5.6 g, Sigma-Aldrich Co.) is added to the solution, followed by the drop-wise addition of acryloyl chloride (5 g, Sigma-Aldrich Co.) with continued stirring, both at a molar ratio of 10:1 with the Pluronic F127. The reaction mixture is stirred overnight and maintained in the inert atmosphere. The diacrylated Pluronic F127 (F127-DA) product is then filtered from the yellow triethylammonium hydrochloride by-product and precipitated from the filtered solution with hexane (Sigma-Aldrich Co.) at a 1:1 volume ratio. The F127-DA is obtained through a second filtration step and allowed to dry in a chemical hood for at least 24 h. This protocol is adapted from ref. 13. For each gram of this base F127-DA mixture, 100 mg of PEG-DA is added, and this solution is mixed in a planetary mixer for 1 min at 2,000 r.p.m. and degassed for 3 min at 2,200 r.p.m. This mixture is then stored in the dark at 4 °C. Finally, 5 w/w% Pt black (Sigma-Aldrich Co.) is added to this base solution at 4 °C and mixed in a planetary mixer for 5 min at 2,000 r.p.m. The Pt-filled F127-DA physically gels during mixing, facilitating loading into a UV-blocking 3-cm3 syringe barrel (EFD Nordson) for printing. This catalytic ink is freshly prepared for each print session, as the Pt black slowly cross-linked the acrylate moieties present in the ink. After EMB3D printing, the catalytic ink is cross-linked for 15 min at 18 mW cm−2 under a UV source (Omnicure EXFO). For EMB3D printing, the syringe barrel housing this ink is fitted with a stainless steel nozzle (0.33-mm inner diameter; EFD Nordson). Two matrix materials are developed for fabricating fully soft robots. The first matrix, referred to as the ‘body matrix’, is prepared by blending two silicone-based materials: Sylgard 184 and SE 1700 (Dow Corning Corp.). SE 1700 is a silicone elastomer paste that contains fumed silica nanoparticles. Sylgard 184 PDMS is used to dilute SE 1700 to achieve the desired rheological response for embedded 3D printing. After exploring several blends, we found that the optimal body matrix is composed of a 1:1 mass ratio of SE 1700 (4:1 ratio of base to hardener) and Sylgard 184 (10:1 ratio of base to hardener). This matrix is prepared by mixing the blend in a planetary mixer at 2,000 r.p.m. for 3 min with degassing at 2,200 r.p.m. for 2 min. The second matrix, referred to as the ‘fuel reservoir matrix’, is prepared by mixing Part A Ecoflex 00-30 to Part B Ecoflex 00-30 (with 1.2 w/w% Slo-Jo Platinum Silicone Cure Retarder and 1.2 w/w% Thivex, Smooth-On Inc.) in a 1:1 ratio. The matrix is prepared in a planetary mixer at 2,000 r.p.m. for 1.5 min with degassing at 2,200 r.p.m. for 1 min. Last, the ‘fugitive plug’ material used to prevent ingress of the body matrix material into the soft controller is prepared before printing by first synthesizing and then mixing a diacrylated Pluronic material (F127-DA) (at 30 wt% in a 0.5 wt% solution of Irgacure 2959 in deionized water) with F127 (at 30 wt% in deionized water) at a mass ratio of 1:4. The fugitive plug is stored in the dark at 4 °C in a syringe. When used, the fugitive plug material is allowed to physically gel before it is cross-linked for 3 min at 6 mW cm−2 under a UV source. All rheological measurements are carried out using a controlled-stress rheometer (DHR-3, TA Instruments) equipped with a 40-mm-diameter, 2° cone and plate geometry. In all experiments, the fugitive and catalytic inks are equilibrated at room temperature for 1 min before testing; the fuel reservoir and body matrix materials are equilibrated for 20 min and 10 min, respectively, to simulate the times at which octobot printing began with each material. Shear storage moduli are measured as a function of shear stress at a frequency of 1 Hz. The body matrix materials are characterized by both flow sweep and flow ramp tests to determine their rheological response (Extended Data Fig. 2). In addition, three-phase modulus recovery tests are carried out to quantify the recovery time of the body matrix stiffness after applying a shear stress that exceeds the equilibrium yield stress, τ (Extended Data Fig. 3). In the first set of experiments, flow sweeps from low (10−2 s−1) to high (102 s−1) shear rates are carried out immediately followed by flow ramps from high to low shear rates. In the second set of experiments, shear storage (G′) and loss (G″) moduli are measured during three phases of applied shear stresses (at 1-Hz frequency): 1 Pa for 3 min; 100 Pa for either 1 s, 10 s or 100 s; and 1 Pa for 30 min. We defined their thixotropic recovery time as the instant G′ = G″, or when tan(δ) = G″/G′ = 1, where δ is the phase angle. Actuators are printed into special actuator characterization moulds by EMB3D printing and then auto-evacuate. To prepare them for characterization, they are first released from mould assembly and then a 1-mm hole is created with a biopsy punch (Miltex Inc.), which serves as the air inlet. Finally, the actuator is pressurized slightly to ensure inflation. Each actuator design is tested for angular displacement (that is, the actuator is allowed to deflect unconstrained and the total displacement angle is measured) and blocked force (that is, the actuator is constrained from deflection and resultant force is measured; see Extended Data Fig. 7). For each actuator, break-in testing consists of five cycles, in which actuator air pressure is slowly (over about 30 s) ramped up to the pressure set point, then slowly (over about 30 s) ramped down to ambient. Pressure set point for the first cycle is P and the set point for all subsequent cycles is P (Extended Data Table 1). Data acquisition consists of five additional cycles for each actuator, in which air pressure is cycled as above to pressure set point P . To characterize their angular displacement, actuators are plumbed with regulated compressed air and mounted vertically between a matte black background and a Sony NEX3 digital camera for video data acquisition. Actuators are pressurized with five break-in cycles as described above, followed by five data-acquisition cycles. As above, the first break-in cycle is to P and all subsequent break-in and data-acquisition cycles are to P . Video data are analysed using the ImageJ image analysis platform (NIH.gov) to obtain the bend angle versus pressure for each actuator. For blocked-force characterization, individual actuators are mounted on a fixed platform beside an Instron model 5544 materials testing frame (Illinois Tool Works Inc.). The actuator is lowered until just above the force sensor portion of the testing frame and the actuator is plumbed with regulated compressed air. Actuators typically behave differently upon the initial few actuations versus subsequent actuations, owing to the Mullins effect29. Each actuator therefore receives five break-in cycles before data acquisition. Air pressure and actuator force data are recorded on the Instron testing frame data acquisition system at 100-ms intervals. Octobot moulds are fabricated inside a CNC machined acetal mould equipped with two locating pins to mount the soft controller. Their desired shape is modelled in SolidWorks (Dessault Systemes SOLIDWORKS Corp.). A negative mould is modelled and output in Parasolid format for file transfer. MasterCAM (CNC Software, Inc.) is used to develop all machining tool paths and to export the final G-code for final fabrication. Blanks (12.7 cm × 7.6 cm × 2.54 cm) were cut from black acetal (Delrin) (McMaster Carr). Acetal is used, owing to its dimensional stability, and 2.54-cm-thick stock is chosen to prevent warping during machining and repeated octobot curing cycles. Octobot moulds are produced by CNC milling on a HAAS OM-2A vertical machining centre (HAAS Automation Inc.). 1-mm dowel pins are pressed into drilled holes for controller mounting. A custom-designed, multi-material 3D printer (ABL 10000, Aerotech Inc.) with four independently z-axis addressable ink reservoirs is used to pattern fugitive and catalytic inks within the octobot matrices27. All G-Code for printing is generated from Python-based software (MeCode, developed by J. Minardi). Prior to EMB3D printing, Ecoflex 30 (Smooth-On, Inc.) is first prepared with 1 wt% Slo-Jo and 0.25 wt% Thivex (both with respect to Part A) by mixing in a Thinky planetary mixer for 1.5 min with a 1-min degas cycle. This uncured Ecoflex 30 is cast into the actuator layers of the octobot mould and degassed in a vacuum chamber for 3 min. A glass slide is used to remove excess material and create smooth surfaces that will ultimately become the extensible layers of the actuators. The moulds are then placed in a 90 °C oven for 30 min to cure the Ecoflex, removed, and trimmed of excess material as necessary. A soft controller is then loaded onto the press-fit pins placed in the printing mould with the polyimide (Kapton) tape still adhered. Registration coordinates and print heights are then taken from the cured Ecoflex layers in the actuators and in all inlets of the soft controller; these are essential for EMB3D printing and provided to the custom print software. The fuel reservoir and body matrix materials are prepared as described previously. While the body matrix material is mixing, the fuel reservoir matrix is deposited in the fuel reservoir region of the printing mould. It is then degassed for 3 min to ensure no trapped gas is present. Excess bubbles in the uncured fuel reservoir matrix are removed with a pipettor. The non-gelled, chilled fugitive plug is then filled throughout the soft controller via injection through the inlets. While the fugitive plug is still in the liquid state, it is briefly degassed in a vacuum chamber. The fugitive plug material is then allowed to physically cross-link, excess gel is scraped from the top of the tape, the tape is removed, and the fugitive plug is photo-cross-linked with a UV source at 6 mW cm−2 for 3 min. After the gels are cross-linked, the body matrix is cast within the mould, covering the fuel reservoir matrix and the fugitive plug-filled soft controller and degassed for 1–3 min in situ. Again, excess bubbles are removed with a pipettor, excess material is scraped off and away from the mould with a glass slide, and EMB3D printing of the fugitive and catalytic inks begins. After printing, the entire mould is cured at 18 mW cm−2 for 15 min to crosslink the catalytic ink. The mould is then transferred to a 90 °C oven, where the matrix materials cross-link. The octobot is removed from the mould and kept at 90 °C for 4 days to facilitate auto-evacuation of the inks. After auto-evacuation, the octobot is release-cut from the surrounding matrix material using a CO laser (Universal Laser Systems) and cleaned with isopropyl alcohol and water. Sylgard 184 PDMS (Dow Corning Corp.) is poured into the open cavity of the octobot above the soft controller to a height of 1.5 mm and cured at 90 °C for 20 min. A 1-mm biopsy punch (Miltex Inc.) is used to punch holes through the newly poured PDMS layer and into the fuel inlets. Dyed water is injected into these holes to inflate the fuel tanks, flow through the system and insure proper bot function. Holes are punched in the downstream vent orifices to allow the water to vent from the system. The octobot is loaded into an acrylic tank outfitted with a backlight to highlight coloured fuel as it flows through the system. Aqueous hydrogen peroxide (90 wt%, HTP grade, Peroxychem) is diluted to 50 wt% and samples dyed red and blue are filled into two syringes prepared with this liquid fuel mixture. The syringes are loaded onto a syringe pump, and connected to the octobot via 1-mm-diameter silicone rubber tubing. Water is flowed into the acrylic tank to wash away dye in the octobot exhaust stream and drained into a nearby sink. The syringe pump flows fuel at a rate of 3 ml min−1 (each syringe) into the octobot for 10 s. The silicone rubber tubing is removed with tweezers from the octobot, which is allowed to operate untethered. The octobot alternates actuation until fuel pressure is insufficient to switch the oscillator and alternating actuation ceases. Photographs and supporting videos are acquired with a digital SLR camera (Canon EOS 5D Mark II, Canon USA Inc.) and a 4K video (Blackmagic Production 4K, Blackmagic Design). Photos are cropped using Inkscape vector graphics editor (http://www.inkscape.org) and video sequences are clipped from raw footage and exported using iMovie (Apple Corp.; titles are added using Premiere Pro, Adobe Systems, Inc.). All print parameter measurements and images of EMB3D printed features in octobots are taken with a digital zoom microscope (VHX-2000, Keyence). Their mean values and standard deviations are determined from three samples printed at each print speed of interest. The octobot represents a minimal soft robotic system that demonstrates our integrated design and fabrication strategy. In our self-contained microfluidic controllers, system scaling is limited by fuel flow rate, on-board fuel supply, downstream decomposition/expansion and actuation-network design. At 50% concentration by weight, 1 g of aqueous hydrogen peroxide expands to approximately 200 ml of gas under ambient pressure and temperature conditions12. Our oscillator is designed to operate at 40 μl min−1 per channel (80 μl min−1 total), and our actuators inflate with approximately 0.2 ml at 50 kPa, the equivalent of 0.3 ml at ambient pressure. Hence, with each channel inflating four actuators, our current design has a theoretical maximum oscillation rate of 5.5 switches per minute. Although the controller and actuators could be redesigned for increased performance, any system scaling would require careful balancing of fuel supply, flow rate and actuator requirements. Alternative actuator designs are possible (see Extended Data Fig. 7), but our current actuators produce 0.04 N; therefore, two actuators would theoretically be sufficient to lift the 7-g robot. On the basis of these demonstrated capabilities, we anticipate that more sophisticated microfluidic control systems and logic devices could be readily incorporated within these printed and moulded robots. For example, fluidic versions of electric logic gates have been reported, including NAND/NOR, AND/OR and XOR/XNOR30, 31, 32, and flip-flops and gain valves33, 34, 35. These complex systems are based on well-established, electrical design rules. Implementation of these systems would enable more complex actuation strategies, such as multi-degree-of-freedom actuators in which planned limb motion would prescribe a true gait with aerial and ground phases to lift and propel the soft robot. Alternatively, actuators could be designed to take advantage of material elasticity, in which actuation performs flexion and abduction, and passive limb elasticity provides extension and adduction. One could even envision an actuation strategy in which pneumatic channels act as sensors, providing true closed-loop feedback to the controller.
Yang C.,University of North Texas |
Kaipa U.,University of North Texas |
Mather Q.Z.,TA Instruments |
Wang X.,University of North Texas |
And 4 more authors.
Journal of the American Chemical Society | Year: 2011
We demonstrate that fluorous metal-organic frameworks (FMOFs) are highly hydrophobic porous materials with a high capacity and affinity to C 6-C 8 hydrocarbons of oil components. FMOF-1 exhibits reversible adsorption with a high capacity for n-hexane, cyclohexane, benzene, toluene, and p-xylene, with no detectable water adsorption even at near 100% relative humidity, drastically outperforming activated carbon and zeolite porous materials. FMOF-2, obtained from annealing FMOF-1, shows enlarged cages and channels with double toluene adsorption vs FMOF-1 based on crystal structures. The results suggest great promise for FMOFs in applications such as removal of organic pollutants from oil spills or ambient humid air, hydrocarbon storage and transportation, water purification, etc. under practical working conditions. © 2011 American Chemical Society.
News Article | November 14, 2016
Market Research Report on Differential Scanning Calorimeter (DSC) market 2016 is a professional and in-depth study on the current state of the Differential Scanning Calorimeter (DSC) worldwide. First of all,"Global Differential Scanning Calorimeter (DSC) Market 2016" report provides a basic overview of the Differential Scanning Calorimeter (DSC) industry including definitions, classifications, applications and Differential Scanning Calorimeter (DSC) industry chain structure. The analysis is provided for the Differential Scanning Calorimeter (DSC) international market including development history, Differential Scanning Calorimeter (DSC) industry competitive landscape analysis. This report "Worldwide Differential Scanning Calorimeter (DSC) Market 2016" also states import/export, supply and consumption figures and Differential Scanning Calorimeter (DSC) market cost, price, revenue and Differential Scanning Calorimeter (DSC) market's gross margin by regions (United States, EU, China and Japan), as well as other regions can be added in Differential Scanning Calorimeter (DSC) Market area. Major Manufacturers are covered in this research report are PerkinElmer Malvern NETZSCH TA Instruments SHIMADZU LINSEIS Rigaku Intertek This report studies Differential Scanning Calorimeter (DSC) in Global market, especially in North America, Europe, China, Japan, Southeast Asia and India, focuses on top manufacturers in global market, with sales, price, revenue and market share. Then, the report focuses on worldwide Differential Scanning Calorimeter (DSC) market key players with information such as company profiles with product picture as well as specification. Related information to Differential Scanning Calorimeter (DSC) market- capacity, production, price, cost, revenue and contact information. Aslo includes Differential Scanning Calorimeter (DSC) industry's - Upstream raw materials, equipment and downstream consumers analysis is also carried out. What’s more, the Differential Scanning Calorimeter (DSC) market development trends and Differential Scanning Calorimeter (DSC) industry marketing channels are analyzed. Finally, "Worldwide Differential Scanning Calorimeter (DSC) Market" Analysis- feasibility of new investment projects is assessed, and overall research conclusions are offered.
Hansen L.D.,Brigham Young University |
Fellingham G.W.,Brigham Young University |
Russell D.J.,TA Instruments
Analytical Biochemistry | Year: 2011
Calorimetric methods have been used to determine equilibrium constants since 1937, but no comprehensive review of the various calorimeters and methods has been done previously. This article reports methods for quantitative comparison of the capabilities of calorimeters for simultaneous determination of equilibrium constants and enthalpy changes, for determining optimal experimental conditions, and for assessing the effects of systematic and random errors on the accuracy and precision of equilibrium constants and enthalpy changes determined by this method. © 2010 Elsevier Inc. All rights reserved.
News Article | December 26, 2016
Dynamic Mechanical Analyzer (DMA) is a testing and analytical instrument that measures the physical properties of solids and polymer melts, reports modulus and damping, and is programmable to measure the relationship between the force, stress, strain, frequency and temperature. This report focuses on the Dynamic Mechanical Analyzer (DMA) in Global market, especially in North America, Europe and Asia-Pacific, South America, Middle East and Africa. This report categorizes the market based on manufacturers, regions, type and application. For more information or any query mail at firstname.lastname@example.org Market Segment by Regions, regional analysis covers North America (USA, Canada and Mexico) Europe (Germany, France, UK, Russia and Italy) Asia-Pacific (China, Japan, Korea, India and Southeast Asia) South America, Middle East and Africa Market Segment by Applications, can be divided into Research Institute Industrial There are 13 Chapters to deeply display the global Dynamic Mechanical Analyzer (DMA) market. Chapter 2, to analyze the top manufacturers of Dynamic Mechanical Analyzer (DMA), with sales, revenue, and price of Dynamic Mechanical Analyzer (DMA), in 2015 and 2016; Chapter 3, to display the competitive situation among the top manufacturers, with sales, revenue and market share in 2015 and 2016; Chapter 4, to show the global market by regions, with sales, revenue and market share of Dynamic Mechanical Analyzer (DMA), for each region, from 2011 to 2016; 2 Manufacturers Profiles 2.1 TA Instruments 2.1.1 Business Overview 2.1.2 Dynamic Mechanical Analyzer (DMA) Type and Applications 22.214.171.124 Type 1 126.96.36.199 Type 2 2.1.3 TA Instruments Dynamic Mechanical Analyzer (DMA) Sales, Price, Revenue, Gross Margin and Market Share 2.2 Netzsch 2.2.1 Business Overview 2.2.2 Dynamic Mechanical Analyzer (DMA) Type and Applications 188.8.131.52 Type 1 184.108.40.206 Type 2 2.2.3 Netzsch Dynamic Mechanical Analyzer (DMA) Sales, Price, Revenue, Gross Margin and Market Share 2.3 Hitachi High-Technologies 2.3.1 Business Overview 2.3.2 Dynamic Mechanical Analyzer (DMA) Type and Applications 220.127.116.11 Type 1 18.104.22.168 Type 2 2.3.3 Hitachi High-Technologies Dynamic Mechanical Analyzer (DMA) Sales, Price, Revenue, Gross Margin and Market Share 2.4 Mettler-Toledo 2.4.1 Business Overview 2.4.2 Dynamic Mechanical Analyzer (DMA) Type and Applications 22.214.171.124 Type 1 126.96.36.199 Type 2 2.4.3 Mettler-Toledo Dynamic Mechanical Analyzer (DMA) Sales, Price, Revenue, Gross Margin and Market Share 2.5 PerkinElmer 2.5.1 Business Overview 2.5.2 Dynamic Mechanical Analyzer (DMA) Type and Applications 188.8.131.52 Type 1 184.108.40.206 Type 2 2.5.3 PerkinElmer Dynamic Mechanical Analyzer (DMA) Sales, Price, Revenue, Gross Margin and Market Share 2.6 Metravib(Acoem) 2.6.1 Business Overview 2.6.2 Dynamic Mechanical Analyzer (DMA) Type and Applications 220.127.116.11 Type 1 18.104.22.168 Type 2 2.6.3 Metravib(Acoem) Dynamic Mechanical Analyzer (DMA) Sales, Price, Revenue, Gross Margin and Market Share 2.7 Anton Paar 2.7.1 Business Overview 2.7.2 Dynamic Mechanical Analyzer (DMA) Type and Applications 22.214.171.124 Type 1 126.96.36.199 Type 2 2.7.3 Anton Paar Dynamic Mechanical Analyzer (DMA) Sales, Price, Revenue, Gross Margin and Market Share 3 Global Dynamic Mechanical Analyzer (DMA) Market Competition, by Manufacturer 3.1 Global Dynamic Mechanical Analyzer (DMA) Sales and Market Share by Manufacturer 3.2 Global Dynamic Mechanical Analyzer (DMA) Revenue and Market Share by Manufacturer 3.3 Market Concentration Rate 3.3.1 Top 3 Dynamic Mechanical Analyzer (DMA) Manufacturer Market Share 3.3.2 Top 6 Dynamic Mechanical Analyzer (DMA) Manufacturer Market Share 3.4 Market Competition Trend For more information or any query mail at email@example.com ABOUT US: Wise Guy Reports is part of the Wise Guy Consultants Pvt. Ltd. and offers premium progressive statistical surveying, market research reports, analysis & forecast data for industries and governments around the globe. Wise Guy Reports features an exhaustive list of market research reports from hundreds of publishers worldwide. We boast a database spanning virtually every market category and an even more comprehensive collection of market research reports under these categories and sub-categories. For more information, please visit https://www.wiseguyreports.com
News Article | September 23, 2016
TA Instruments, a manufacturer of analytical instruments for thermal analysis, rheology, and microcalorimetry has acquired Rubotherm, which supplies analytical test instruments for thermogravimetric and sorption measurements. The instruments can be used in industrial and academic research laboratories in disciplines that include chemistry, material science and engineering. Rubotherm’s instruments are based on a patented magnetic suspension balance that allows for contactless measurement of mass changes of samples in a closed reactor under controlled environments with high resolution and accuracy. Applications include gravimetric measurements over a wide temperature range, under vacuum or high pressures, using corrosives, toxics or vapors as reaction atmospheres. ‘Rubotherm brings a great new technology and capability to TA in the form of their patented magnetic suspension balance,’ said Terry Kelly, president of TA Instruments. ‘The application of this technology in TGA opens new markets for TA and further extends our world leading position in thermal analysis.’ This story uses material from TA Instruments, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.
Slough C.G.,TA Instruments
Journal of Testing and Evaluation | Year: 2014
Modulated thermogravimetry (MTG) was introduced by Blaine and Hahn ("Obtaining Kinetic Parameters by Modulated Thermogravimetry," J. Therm. Anal., Vol. 54, 1998, pp. 694-704) of TA Instruments. Since that time it has found popularity as a technique for obtaining activation energies of degradation processes of various materials (Gamlin, C. D., Dutta, N. K., Choudhury, N. Roy, Kehoe, D., and Matisons, J., "Evaluation of Kinetic Parameters of Thermal and Oxidative Decomposition of Base Oils by Conventional Isothermal and Modulated TGA and Pressure DSC," Thermochim. Acta, Vols. 392-393, 2002, pp. 357-369; Mamleev, V. and Bourbigot, S., "Modulated Thermogravimetry in Analysis of Decomposition Kinetics," Chem. Eng. Sci., Vol. 60, 2005, pp. 747-766; Gracia-Fernandez, C. A., Gomez-Barreiro, S., Ruiz-Salvador, S. and Blaine, R.L., "Study of the Degradation of a Thermoset System Using TGA and Modulated TGA," Prog. Organ. Coatings, Vol. 54, 2005, pp. 332-336; Cheng, K., Winter, W. T. and Stipanovic, A. J., "A Modulated TGA Approach to the Kinetics of Lignocellulosic Biomass Pyrolysis/Combustion," Polym. Degrad. Stab., Vol. 97, 2012, pp. 1606-1615). MTG experiments require several parameters, modulation amplitude, modulation period, and ramp rate, to be set. Blaine and Hahn proposed values for these parameters, but no extensive work has been done to define the true operating range of these parameters and the effects on the measured activation energy of varying them. Results reported here attempt to define more clearly the operational boundaries of these parameters, how activation energy changes with them, and how it can be determined that the parameters are chosen correctly. Copyright © 2014 by ASTM International.
Blaine R.,TA Instruments
Journal of Testing and Evaluation | Year: 2014
The history of lifetime testing by thermogravimetry is traced from its origin in the electrical industry in the early 20th century, through the development of synthetic polymers and the development of thermal analytic methods, to the present where thermal analytic standards are available. The impact of thermal analysis, especially thermogravimetry, on the past, present, and future of lifetime testing is explored. Copyright © 2014 by ASTM International.
Slough C.G.,TA Instruments
Journal of Testing and Evaluation | Year: 2014
Modulated thermogravimetry (MTG) was introduced in 1998 by employees of TA Instruments. Since that time it has found popularity as a technique for obtaining activation energies of degradation processes in a variety of materials. The initial work claimed that the repeatability of MTG was superior to that of the Flynn and Wall method. Little information, however, was given concerning the accuracy of the technique, and none was provided concerning its reproducibility. Results reported here test the repeatability claims and explore the questions of accuracy and reproducibility. Copyright © 2014 by ASTM International.
Demarse N.A.,TA Instruments
Methods in molecular biology (Clifton, N.J.) | Year: 2013
Isothermal titration calorimetry (ITC) has emerged as a powerful tool for determining the thermodynamic properties of chemical or physical equilibria such as protein-protein, ligand-receptor, and protein-DNA binding interactions. The utility of ITC for determining kinetic information, however, has not been fully recognized. Methods for collecting and analyzing data on enzyme kinetics are discussed here. The step-by-step process of converting the raw heat output rate into the kinetic parameters of the Michaelis-Menten equation is explicitly stated. The hydrolysis of sucrose by invertase is used to demonstrate the capability of the instrument and method.