scholarly journals Critical Point Drying: An Effective Drying Method for Direct Measurement of the Surface Area of a Pretreated Cellulosic Biomass

Polymers ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 676 ◽  
Author(s):  
Kyu-Young Kang ◽  
Kyung-Ran Hwang ◽  
Ji-Yeon Park ◽  
Joon-Pyo Lee ◽  
Jun-Seok Kim ◽  
...  
Keyword(s):  
Critical Point ◽  
Surface Area ◽  
Direct Measurement ◽  
Cellulosic Biomass ◽  
Drying Method ◽  
Critical Point Drying

scholarly journals Critical Point Drying: An Effective Tool for Direct Measurement of the Surface Area of Pretreated Cellulosic Biomass

2018 ◽  
Author(s):  
Kyu-Young Kang ◽  
Kyung Ran Hwang ◽  
Ji-Yeon Park ◽  
Joon-Pyo Lee ◽  
Jun-Seok Kim ◽  
...  
Keyword(s):  
Critical Point ◽  
Surface Area ◽  
Freeze Drying ◽  
Pore Diameter ◽  
Polar Solvent ◽  
Cellulosic Biomass ◽  
Average Pore ◽  
Freeze Dried ◽  
Critical Point Drying ◽  
Bet Technique

Surface area and pore size distribution of Eucalyptus samples pretreated by different methods were determined by the Brunauer-Emmett-Teller (BET) technique. Three methods were applied to prepare cellulosic biomass samples for BET measurements: air, freeze, and critical point drying (CPD). Air and freeze drying caused severe collapse of biomass pore structures, but CPD effectively preserved biomass morphology. Surface area of CPD prepared Eucalyptus samples was determined to be 58–161 m2/g, whereas air and freeze dried samples were 0.5–1.3 and 1.0–2.4 m2/g, respectively. Average pore diameter of CPD prepared Eucalyptus samples were 61–70Å. CPD preserved Eucalyptus sample morphology by replacing water with a non-polar solvent, CO2 fluid, which prevented hydrogen bond reformation in the cellulose.

scholarly journals Exploration of reduced graphene oxide microparticles as electrocatalytic materials in vanadium redox flow batteries

2021 ◽  
Author(s):  
Amira Alazmi ◽  
Charles Wan ◽  
Pedro Costa ◽  
Fikile Brushett
Keyword(s):  
Graphene Oxide ◽  
Critical Point ◽  
Reduced Graphene Oxide ◽  
Surface Area ◽  
Reaction Rates ◽  
Redox Flow Batteries ◽  
Reduced Graphene ◽  
Critical Point Drying ◽  
Flow Batteries ◽  
Vanadium Redox

Augmenting reaction rates on porous carbon electrodes is critical for reducing the cost of all-vanadium redox flow batteries (VRFBs). To this end, reduced graphene oxide (rGO) based carbons hold promise, demonstrating high specific surface area, chemomechanical stability, and electrochemical activity. While initial efforts have shown that rGOs can enhance VRFB performance, the range of unique processing conditions leads to a collection of materials with disparate elemental composition and porous structure, thus obscuring performance-determining characteristics behind redox reactions and frustrating the development of generalizable design principles. Here, we generate rGO electrocatalysts of nearly identical chemical composition but different textures (i.e., surface area and pore structure) by varying the drying step in the graphene synthesis (i.e., vacuum-drying vs. carbon dioxide critical point drying). We apply spectroscopic and electrochemical techniques on the synthesized rGOs, observing a three-fold increase in BET surface area using critical point drying. We subsequently decorate carbon felt electrodes – both pristine and thermally activated – with rGO microparticles via a flow deposition procedure, and evaluate their performance and durability in a VRFB cell. The synthesis approach and findings described in this work inform and complement efforts to advance the material science and engineering of rGO electrocatalysts.

Critical Point Drying Method Using Dry Ice

1974 ◽  
Vol 49 (4) ◽  
pp. 203-206 ◽  
Author(s):  
Keiichi Tanaka ◽  
Akihiro Iino
Keyword(s):  
Critical Point ◽  
Drying Method ◽  
Dry Ice ◽  
Critical Point Drying

Electron microscopy of T1-bacteriophage adsorbed to clay minerals: application of the critical point drying method

1975 ◽  
Vol 21 (8) ◽  
pp. 1278-1282 ◽  
Author(s):  
Vojtech Bystricky ◽  
G. Stotzky ◽  
Milton Schiffenbauer
Keyword(s):  
Electron Microscopy ◽  
Critical Point ◽  
Clay Minerals ◽  
Surface Interaction ◽  
Drying Method ◽  
Critical Point Drying

A T1-bacteriophage appears to be strongly adsorbed by clay minerals. The critical point drying method has been used to facilitate visualization of this surface interaction by electron microscopy.

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