scholarly journals Long-Term Thermal Aging of Modified Sylgard 184 Formulations

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3125
Author(s):  
Zachary Brounstein ◽  
Jianchao Zhao ◽  
Drew Geller ◽  
Nevin Gupta ◽  
Andrea Labouriau
Keyword(s):  
Material Properties ◽  
High Performance ◽  
Room Temperature ◽  
Microelectromechanical Systems ◽  
Accelerated Aging ◽  
Time Frame ◽  
Gel Point ◽  
Gas Generation ◽  
Gas Products

Primarily used as an encapsulant and soft adhesive, Sylgard 184 is an engineered, high-performance silicone polymer that has applications spanning microfluidics, microelectromechanical systems, mechanobiology, and protecting electronic and non-electronic devices and equipment. Despite its ubiquity, there are improvements to be considered, namely, decreasing its gel point at room temperature, understanding volatile gas products upon aging, and determining how material properties change over its lifespan. In this work, these aspects were investigated by incorporating well-defined compounds (the Ashby–Karstedt catalyst and tetrakis (dimethylsiloxy) silane) into Sylgard 184 to make modified formulations. As a result of these additions, the curing time at room temperature was accelerated, which allowed for Sylgard 184 to be useful within a much shorter time frame. Additionally, long-term thermal accelerated aging was performed on Sylgard 184 and its modifications in order to create predictive lifetime models for its volatile gas generation and material properties.

scholarly journals Resistance of a Silicone Membrane to Long-term UV and Moisture Aging in Light of Climate Change

2021 ◽  
Author(s):  
Jean-François Masson ◽  
Peter Collins ◽  
Marzieh Riahinezhad ◽  
Itzel Lopez-Carreon ◽  
Jocelyn Johansen
Keyword(s):  
Climate Change ◽  
Material Characterization ◽  
Room Temperature ◽  
Accelerated Aging ◽  
Building Envelope ◽  
Degradation Mechanisms ◽  
Aging Conditions ◽  
And Storage ◽  
Silicone Membranes

Three room-temperature fluid-applied silicone membranes intended for application in the building envelope were studied in this work. The membranes were subjected to 5000 hours of accelerated UV and moisture aging to evaluate their resistance to long-term aging. The properties of the membranes were studied to understand any degradation mechanisms that might happen during accelerated aging. The weight loss, wetting propensity, cracking and oxidation resistance, and storage modulus were measured at different intervals during the 5000 hours of aging. Based on the material characterization results, the silicone membranes proved to be resilient under aggressive accelerated UV radiation and moisture aging, conditions which can be expected as a result of climate change.

scholarly journals Long-Term Stability of Lorazepam in Sodium Chloride 0.9% Stored at Different Temperatures in Different Containers

2019 ◽  
Vol 55 (3) ◽  
pp. 188-192
Author(s):  
M. L. Colsoul ◽  
A. Breuer ◽  
N. Goderniaux ◽  
J. D. Hecq ◽  
L. Soumoy ◽  
...  
Keyword(s):  
Time Management ◽  
High Performance ◽  
Room Temperature ◽  
Color Change ◽  
Storage Period ◽  
Term Stability ◽  
Long Term Stability ◽  
Glass Bottles ◽  
The Stability

Background and Objective: Infusion containing lorazepam is used by geriatric department to limit anxiety disorders in the elderly. Currently, these infusions are prepared according to demand by the nursing staff, but the preparation in advance in a centralized service could improve quality of preparation and time management. The aim of this study was to investigate the long-term stability of this infusion in polypropylene syringes stored at 5 ± 3°C. Then, results obtained were compared with stability data of lorazepam in syringes stored at room temperature, glass bottles at 5 ± 3°C, and glass bottles at room temperature. Method: Eight syringes and 6 bottles of infusion were prepared by diluting 1 mL lorazepam 4 mg in 23 mL of NaCl 0.9% under aseptic conditions. Five syringes and 3 bottles were stored at 5 ± 3°C and 3 syringes and 3 bottles were stored at room temperature for 30 days. During the storage period, particle appearance or color change were periodically checked by visual and microscope inspection. Turbidity was assessed by measurements of optical density (OD) at 3 wavelengths (350 nm, 410 nm, 550 nm). The stability of pH was also evaluated. The lorazepam concentrations were measured at each time point by high-performance liquid chromatography with ultraviolet detector at 220 nm. Results: Solutions were physically unstable in syringes at 5 ± 3°C after 4 days: crystals and a drop of OD at 350 nm were observed. However, pH was stable. After 2 days, solutions were considered as chemically unstable because a loss of lorazepam concentration higher than 10% was noticed: the lower 1-sided confidence limit at 95% was below 90% of the initial concentration. To assess temperature and polypropylene influence, results were compared with those obtained for syringes at room temperature and bottles at 5 ± 3°C and room temperature. Precipitation, drop of OD at 350 nm, and chemical instability were observed in all conditions. Conclusion: Solutions of lorazepam were unstable after 2 days in syringes at 5 ± 3°C. Preparation in advance appears, therefore, not possible for the clinical use. Storage conditions (temperature and form) do not improve the stability.

Annealing-free and strongly adhesive silver nanowire networks with long-term reliability by introduction of a nonconductive and biocompatible polymer binder

Nanoscale ◽  
2014 ◽  
Vol 6 (9) ◽  
pp. 4812-4818 ◽  
Author(s):  
Yunxia Jin ◽  
Dunying Deng ◽  
Yuanrong Cheng ◽  
Lingqiang Kong ◽  
Fei Xiao
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Alginic Acid ◽  
Spray Coating ◽  
Polymer Binder ◽  
Silver Nanowire ◽  
Biocompatible Polymer ◽  
One Step ◽  
Nanowire Networks

A high-performance AgNW composite film was fabricated using a complex of alginic acid and poly(dopamine) as a binder via a simple and fast one-step spray coating technique at room temperature.

A review: electrical and gas sensing properties of polyaniline/ferrite nanocomposites

Sensor Review ◽  
2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Thejas Ramakrishnaiah ◽  
Prasanna Gunderi Dhananjaya ◽  
Chaturmukha Vakwadi Sainagesh ◽  
Sathish Reddy ◽  
Swaroop Kumaraswamy ◽  
...  
Keyword(s):  
Gas Sensors ◽  
High Performance ◽  
Room Temperature ◽  
Gas Sensing ◽  
Cost Effective ◽  
Content Type ◽  
Sensing Properties ◽  
Long Term Stability ◽  
Gas Sensing Properties

Purpose This paper aims to study the various developments taking place in the field of gas sensors made from polyaniline (PANI) nanocomposites, which leads to the development of high-performance electrical and gas sensing materials operating at room temperature. Design/methodology/approach PANI/ferrite nanocomposites exhibit good electrical properties with lower dielectric losses. There are numerous reports on PANI and ferrite nanomaterial-based gas sensors which have good sensing response, feasible to operate at room temperature, requires less power and cost-effective. Findings This paper provides an overview of electrical and gas sensing properties of PANI/ferrite nanocomposites having improved selectivity, long-term stability and other sensing performance of sensors at room temperature. Originality/value The main purpose of this review paper is to focus on PANI/ferrite nanocomposite-based gas sensors operating at room temperature.

scholarly journals High Performance Voltage Tailorable Room-temperature Ca-metal Batteries

2020 ◽  
Author(s):  
Huawei Song ◽  
Jian Su ◽  
Chengxin Wang
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Daily Life ◽  
Energy Performance ◽  
Proof Of Concept ◽  
Capacity Retention ◽  
Long Term Stability ◽  
Calcium Metal ◽  
High Output

Abstract Calcium metal battery as one of the promising alternatives beyond Li-metal technology is challenged by the lack of suitable cathodes with considerable energy performance, and stable Ca anode of long-term stability and lower polorization potentials for Ca-plating/stripping. Here, by recycling cellulose waste paper of wide sources in our daily life, we develop feasible cathodes for Ca-metal batteries of good high-voltage and wide-window-voltage adaptability (0.005-4.9 V vs. Ca/Ca2+), except for considerable energy performance (~517.5 Wh kg-1 at 0.1 A g-1). Meanwhile, through tailorable Ca-plating/stripping potentials (∆V= ~0.65 V) induced by electrolyte modification, proof-of-concept Ca-metal batteries not only delivered enhanced storage capability (101 mAh g-1 vs. 51 mAh g-1 at 0.1 A g-1 in the window voltage of 2.0-4.7 V ) and cycling stability (~77% capacity retention for 100 cycles), but also simutaneously held high output average working voltage of ~3.2V.

Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson
Keyword(s):  
Complex Formation ◽  
Significant Influence ◽  
Room Temperature ◽  
Ph Value ◽  
Maximum Activity ◽  
Reduction Step ◽  
Labelling Yield ◽  
Different Temperatures ◽  
Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

The Recent Revolution in High Performance Computing

MRS Bulletin ◽  
1997 ◽  
Vol 22 (10) ◽  
pp. 5-6
Author(s):  
Horst D. Simon
Keyword(s):  
High Performance Computing ◽  
High Performance ◽  
New Technologies ◽  
New Technology ◽  
Parallel Architecture ◽  
Time Frame ◽  
Good News ◽  
Computing Industry ◽  
Time And Energy ◽  
Performance Computing

Recent events in the high-performance computing industry have concerned scientists and the general public regarding a crisis or a lack of leadership in the field. That concern is understandable considering the industry's history from 1993 to 1996. Cray Research, the historic leader in supercomputing technology, was unable to survive financially as an independent company and was acquired by Silicon Graphics. Two ambitious new companies that introduced new technologies in the late 1980s and early 1990s—Thinking Machines and Kendall Square Research—were commercial failures and went out of business. And Intel, which introduced its Paragon supercomputer in 1994, discontinued production only two years later.During the same time frame, scientists who had finished the laborious task of writing scientific codes to run on vector parallel supercomputers learned that those codes would have to be rewritten if they were to run on the next-generation, highly parallel architecture. Scientists who are not yet involved in high-performance computing are understandably hesitant about committing their time and energy to such an apparently unstable enterprise.However, beneath the commercial chaos of the last several years, a technological revolution has been occurring. The good news is that the revolution is over, leading to five to ten years of predictable stability, steady improvements in system performance, and increased productivity for scientific applications. It is time for scientists who were sitting on the fence to jump in and reap the benefits of the new technology.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

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