Facile fabrication of marshmallow-like gels as flexible thermal insulators and liquid nitrogen retention materials: Application to a cryopreserved embryo container

2017 ◽  
Author(s):  
Gen Hayase ◽  
Yasutaka Ohya
Keyword(s):  
Thermal Conductivity ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Pore Diameter ◽  
Nitrogen Retention ◽  
Water Bottle ◽  
Silicon Alkoxide ◽  
Cryopreserved Embryo ◽  
Facile Fabrication ◽  
High Flexibility

<p>Low bulk density porous monoliths were prepared by using two types of silicon alkoxide methyltrimethoxysilane (MTMS) and dimethyldimethoxysilane (DMDMS) as precursors and controlling phase separation under appropriate conditions. By changing the ratio of the aqueous solution to the precursors in the starting composition, it was possible to control the microstructure of the resulting porous monoliths or to prepare microparticles. Those marshmallow-like monoliths with a skeleton diameter of a few micrometers and pore diameter of several tens micrometers has high flexibility against compression and bending, and shows low thermal conductivity of ~30 mW m<sup>−1</sup> K<sup>−1</sup> at room temperature. We show that those materials can be used as a simple cryopreserved embryo container like small dry shippers by packing gels and adsorbing liquid nitrogen in a vacuum-insulated water bottle.</p>

Facile fabrication of marshmallow-like gels as flexible thermal insulators and liquid nitrogen retention materials: Application to a cryopreserved embryo container

2017 ◽  
Author(s):  
Gen Hayase ◽  
Yasutaka Ohya
Keyword(s):  
Thermal Conductivity ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Pore Diameter ◽  
Nitrogen Retention ◽  
Water Bottle ◽  
Silicon Alkoxide ◽  
Cryopreserved Embryo ◽  
Facile Fabrication ◽  
High Flexibility

<p>Low bulk density porous monoliths were prepared by using two types of silicon alkoxide methyltrimethoxysilane (MTMS) and dimethyldimethoxysilane (DMDMS) as precursors and controlling phase separation under appropriate conditions. By changing the ratio of the aqueous solution to the precursors in the starting composition, it was possible to control the microstructure of the resulting porous monoliths or to prepare microparticles. Those marshmallow-like monoliths with a skeleton diameter of a few micrometers and pore diameter of several tens micrometers has high flexibility against compression and bending, and shows low thermal conductivity of ~30 mW m<sup>−1</sup> K<sup>−1</sup> at room temperature. We show that those materials can be used as a simple cryopreserved embryo container like small dry shippers by packing gels and adsorbing liquid nitrogen in a vacuum-insulated water bottle.</p>

A Liquid Nitrogen Cooled Stage for STEM

1974 ◽  
Vol 32 ◽  
pp. 444-445
Author(s):  
Louis T. Germinario
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Objective Lens ◽  
Thermal Drift ◽  
Specimen Holder ◽  
Resolution Capability ◽  
Focal Position

A liquid nitrogen stage has been developed for the JEOL JEM-100B electron microscope equipped with a scanning attachment. The design is a modification of the standard JEM-100B SEM specimen holder with specimen cooling to any temperatures In the range ~ 55°K to room temperature. Since the specimen plane is maintained at the ‘high resolution’ focal position of the objective lens and ‘bumping’ and thermal drift la minimized by supercooling the liquid nitrogen, the high resolution capability of the microscope is maintained (Fig.4).

High thermal conductivity of pure dense SiC ceramics prepared via HTPVT

2019 ◽  
Vol 12 (03) ◽  
pp. 1950032 ◽  
Author(s):  
Yuchen Deng ◽  
Yaming Zhang ◽  
Nanlong Zhang ◽  
Qiang Zhi ◽  
Bo Wang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Grain Size ◽  
Phase Composition ◽  
Room Temperature ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Growth Substrate ◽  
Sic Ceramics ◽  
Evolution Of Microstructure

Pure dense silicon carbide (SiC) ceramics were obtained via the high-temperature physical vapor transport (HTPVT) method using graphite paper as the growth substrate. The phase composition, the evolution of microstructure, the thermal diffusivity and thermal conductivity at RT to 200∘C were investigated. The obtained samples had a relative density of higher than 98.7% and a large grain size of 1[Formula: see text]mm, the samples also had a room-temperature thermal conductivity of [Formula: see text] and with the temperature increased to 200∘C, the thermal conductivity still maintained at [Formula: see text].

scholarly journals Local ferroelectric polarization switching driven by nanoscale distortions in thermoelectric $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aastha Vasdev ◽  
Moinak Dutta ◽  
Shivam Mishra ◽  
Veerpal Kaur ◽  
Harleen Kaur ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Lattice Thermal Conductivity ◽  
Direct Evidence ◽  
Temperature Dependent ◽  
Force Microscopy ◽  
Ferroelectric Domains ◽  
Pdf Analysis ◽  
Ferroelectric Transition Temperature

AbstractA remarkable decrease in the lattice thermal conductivity and enhancement of thermoelectric figure of merit were recently observed in rock-salt cubic SnTe, when doped with germanium (Ge). Primarily, based on theoretical analysis, the decrease in lattice thermal conductivity was attributed to local ferroelectric fluctuations induced softening of the optical phonons which may strongly scatter the heat carrying acoustic phonons. Although the previous structural analysis indicated that the local ferroelectric transition temperature would be near room temperature in $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$ Sn 0.7 Ge 0.3 Te , a direct evidence of local ferroelectricity remained elusive. Here we report a direct evidence of local nanoscale ferroelectric domains and their switching in $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$ Sn 0.7 Ge 0.3 Te using piezoeresponse force microscopy(PFM) and switching spectroscopy over a range of temperatures near the room temperature. From temperature dependent (250–300 K) synchrotron X-ray pair distribution function (PDF) analysis, we show the presence of local off-centering distortion of Ge along the rhombohedral direction in global cubic $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$ Sn 0.7 Ge 0.3 Te . The length scale of the $${\text {Ge}}^{2+}$$ Ge 2 + off-centering is 0.25–0.10 Å near the room temperatures (250–300 K). This local emphatic behaviour of cation is the cause for the observed local ferroelectric instability, thereby low lattice thermal conductivity in $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$ Sn 0.7 Ge 0.3 Te .

Thermal Conductivity of Room Temperature Deep Eutectic Solvents

2021 ◽  
Author(s):  
Noor Albayati ◽  
Mohammed Kadhom ◽  
Ghassan Abdullah ◽  
Suhaib Salih
Keyword(s):  
Thermal Conductivity ◽  
Room Temperature ◽  
Deep Eutectic Solvents

scholarly journals Composite Material of PDMS with Interchangeable Transmittance: Study of Optical, Mechanical Properties and Wettability

2021 ◽  
Vol 5 (4) ◽  
pp. 110
Author(s):  
Flaminio Sales ◽  
Andrews Souza ◽  
Ronaldo Ariati ◽  
Verônica Noronha ◽  
Elder Giovanetti ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Room Temperature ◽  
Casting Process ◽  
Optical Characteristics ◽  
Smart Devices ◽  
Superhydrophobic Coating ◽  
Gravity Casting ◽  
High Flexibility ◽  
Physical And Chemical

Polydimethylsiloxane (PDMS) is a polymer that has attracted the attention of researchers due to its unique properties such as transparency, biocompatibility, high flexibility, and physical and chemical stability. In addition, PDMS modification and combination with other materials can expand its range of applications. For instance, the ability to perform superhydrophobic coating allows for the manufacture of lenses. However, many of these processes are complex and expensive. One of the most promising modifications, which consists of the development of an interchangeable coating, capable of changing its optical characteristics according to some stimuli, has been underexplored. Thus, we report an experimental study of the mechanical and optical properties and wettability of pure PDMS and of two PDMS composites with the addition of 1% paraffin or beeswax using a gravity casting process. The composites’ tensile strength and hardness were lower when compared with pure PDMS. However, the contact angle was increased, reaching the highest values when using the paraffin additive. Additionally, these composites have shown interesting results for the spectrophotometry tests, i.e., the material changed its optical characteristics when heated, going from opaque at room temperature to transparent, with transmittance around 75%, at 70 °C. As a result, these materials have great potential for use in smart devices, such as sensors, due to its ability to change its transparency at high temperatures.

scholarly journals Above-room-temperature giant thermal conductivity switching in spintronic multilayers

2021 ◽  
Vol 118 (4) ◽  
pp. 042409
Author(s):  
Hiroyasu Nakayama ◽  
Bin Xu ◽  
Sotaro Iwamoto ◽  
Kaoru Yamamoto ◽  
Ryo Iguchi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Room Temperature ◽  
Conductivity Switching

scholarly journals Research on Thermal Stability and Properties of Ca3ZrSi2O9 as Potential T/EBC Materials

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 583
Author(s):  
Yangyang Pan ◽  
Bo Liang ◽  
Yaran Niu ◽  
Dijuan Han ◽  
Dongdong Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Fracture Toughness ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Mechanical And Thermal Properties ◽  
Self Healing ◽  
Barrier Coating

In this study, a new coating material for thermal barrier coating (TBC) or environment barrier coating (EBC) application, Ca3ZrSi2O9 (CZSO), was synthesized and prepared by atmospheric plasma spray (APS) technology. The evolution of the phases and microstructures of the coatings with different thermal-aged were characterized by XRD, XRF, EDS and SEM, respectively. The thermal stability was measured by TG-DTA and DSC. The mechanical and thermal properties, including Vickers hardness (HV), fracture toughness (KIC), thermal conductivity () and coefficient of thermal expansion (CTE) were focused on. It was found that the as-sprayed CZSO coating contained amorphous phase. Crystalline transformation happened at 900–960 ∘C and no mass changes took place from room temperature (RT) to 1300 ∘C. The phenomena of microcrack self-healing and composition uniformity were observed during thermal aging. The of coating was very low at about 0.57–0.80 Wm−1K−1 in 200–1200 ∘C. The combined properties indicated that the CZSO coating might be a potential T/EBC material.

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