scholarly journals Supercritical Carbon Dioxide Impregnation of Gold Nanoparticles Demonstrates a New Route for the Fabrication of Hybrid Silk Materials

Insects ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 18
Author(s):  
Manish Singh ◽  
Estera S. Dey ◽  
Sunil Bhand ◽  
Cedric Dicko
Keyword(s):  
Carbon Dioxide ◽  
Gold Nanoparticles ◽  
Supercritical Carbon Dioxide ◽  
Structural Changes ◽  
Combined Effects ◽  
Silk Fibers ◽  
Carrier Fluid ◽  
Concentration Time ◽  
Gold Nps ◽  
Supercritical Carbon

How many nanoparticles can we load in a fiber? How much will leak? Underlying is the relatively new question of the “space available” in fibers for nanoparticle loading. Here, using supercritical carbon dioxide (scCO2) as a carrier fluid, we explored the impregnation in four Indian silks (Mulberry, Eri, Muga, and Tasar) with five standard sizes of gold nanoparticles (5, 20, 50, 100 and 150 nm in diameter). All silks could be permanently impregnated with nanoparticles up to 150 nm in size under scCO2 impregnation. Accompanying structural changes indicated that the amorphous silk domains reorganized to accommodate the gold NPs. The mechanism was studied in detail in degummed Mulberry silk fibers (i.e., without the sericin coating) with the 5 nm nanoparticle. The combined effects of concentration, time of impregnation, scCO2 pressure, and temperature showed that only a narrow set of conditions allowed for permanent impregnation without deterioration of the properties of the silk fibers.

Macroscale Mechanical and Microscale Structural Changes in Chinese Wufeng Shale With Supercritical Carbon Dioxide Fracturing

SPE Journal ◽  
2017 ◽  
Vol 23 (03) ◽  
pp. 691-703 ◽  
Author(s):  
Qing-You Liu ◽  
Lei Tao ◽  
Hai-Yan Zhu ◽  
Zheng-Dong Lei ◽  
Shu Jiang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Shale Gas ◽  
Structural Changes ◽  
Triaxial Tests ◽  
Upper Ordovician ◽  
Sem Images ◽  
Bedding Planes ◽  
Before And After ◽  
Supercritical Carbon

Summary Waterless fracturing for shale-gas exploitation using supercritical carbon dioxide (scCO2) is both effective and environmentally friendly, and has become an extensive research topic. Previous researchers have focused on the chemical and physical properties and microstructure of sandstone, carbonate, and shale caprock, rather than on the properties of shale-gas formations. The macroscale mechanical properties and microscale fracture characteristics of Wufeng Shale exposed to scCO2 (at greater than 31.8°C and 7.29 MPa) are still not well-understood. To study the macroscale and microscale changes of shale subjected to scCO2, we obtained Chinese Wufeng Shale crops (Upper Ordovician Formation) from Yibin, Sichuan Basin, China. The shale samples were divided into two groups. The first group was exposed to scCO2, and the second group was exposed to nitrogen (N2). Scanning-electron-microscope (SEM) and X-ray-diffraction (XRD) images were taken to study the original microstructure and mineral content of the shale. To study the macroscale mechanical changes of Wufeng Shale immersed in scCO2 or N2 for 10 hours, triaxial tests with controlled coring angles were conducted. SEM and XRD images were taken after the triaxial tests. In the SEM images, tight bedding planes and undamaged minerals (with sharp edges and smooth surfaces) were found in N2-treated samples both before and after testing, indicating that exposure to N2 did not affect the microstructures. However, the SEM images for the microstructure scCO2-treated samples before and after testing were quite different. The bedding planes were damaged, which left some connected microfractures and corrosion holes, and some mineral types were broken into small particles and left with uneven mineral surfaces. This shows that scCO2 can change rock microstructures and make some minerals (e.g., calcite) fracture more easily. The complex microscale fractures and the decrease in strength for scCO2-treated shale aid the seepage and gathering of gas, enhancing shale-gas recovery. Knowledge of the multiscale physical and chemical changes of shale exposed to scCO2 is not only essential for scCO2 fracturing, but it is also important for scCO2 jets used to break rock and for the geological storage of CO2.

Lyophilization-Induced Structural Changes in Solvent-Swollen and Supercritical Carbon Dioxide Treated Low-Rank Turkish Coals and Characterization of Their Extracts

2005 ◽  
Vol 19 (3) ◽  
pp. 1056-1064 ◽  
Author(s):  
Serkan Baş ◽  
Billur Sakintuna ◽  
Burak Birkan ◽  
Yusuf Menceloglu ◽  
Alpay Taralp ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Structural Changes ◽  
Low Rank ◽  
Supercritical Carbon

scholarly journals Structural Changes in Poly(ethylene terephthalate) Induced by Supercritical Carbon Dioxide Containing a Cosolvent as a Modifier

2006 ◽  
Vol 62 (8) ◽  
pp. 180-185
Author(s):  
Kazumasa Hirogaki ◽  
Xi Zhao ◽  
Isao Tabata ◽  
Kenji Hisada ◽  
Satoko Okubayashi ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Structural Changes ◽  
Ethylene Terephthalate ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Supercritical Carbon

Synthesis of Gold Nanoparticles from an Organometallic Compound in Supercritical Carbon Dioxide

Langmuir ◽  
2004 ◽  
Vol 20 (13) ◽  
pp. 5189-5191 ◽  
Author(s):  
Kunio Esumi ◽  
Susumu Sarashina ◽  
Tomokazu Yoshimura
Keyword(s):  
Carbon Dioxide ◽  
Gold Nanoparticles ◽  
Supercritical Carbon Dioxide ◽  
Organometallic Compound ◽  
Supercritical Carbon

Germanium Nanowire Synthesis from Fluorothiolate-Capped Gold Nanoparticles in Supercritical Carbon Dioxide

2010 ◽  
Vol 22 (18) ◽  
pp. 5235-5243 ◽  
Author(s):  
Gillian Collins ◽  
Maria Koleśnik ◽  
Vojislav Krstić ◽  
Justin D. Holmes
Keyword(s):  
Carbon Dioxide ◽  
Gold Nanoparticles ◽  
Supercritical Carbon Dioxide ◽  
Nanowire Synthesis ◽  
Supercritical Carbon
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