A Surfactant-Free Microfluidic Process for Fabrication of Multi-Hollow Polyimide Aerogel Particles

2020 ◽  
Vol 35 (5) ◽  
pp. 481-492
Author(s):  
Y. M. Yao ◽  
P. Joo ◽  
S. C. Jana
Keyword(s):  
Thermal Insulation ◽  
Supercritical Drying ◽  
Bet Surface Area ◽  
Liquid Droplets ◽  
Emulsion System ◽  
Droplet Generator ◽  
Flow Rates ◽  
Oil Emulsion ◽  
Gel Particles ◽  
Microfluidic Flows

Abstract This work focuses on fabrication of multi-hollow polyimide gel and aerogel particles from a surfactant-free oil-in-oil emulsion system using a microfluidic droplet generator operating under dripping mode. The multi-hollow gel and aerogel particles have strong potential in thermal insulation. Under jetting and tip-streaming regime of microfluidic flows, droplets are generated with no occluded liquid phase. The present study investigates a means of designing polyimide gel particles with plurality of internal liquid droplets by strategically manipulating the flow rates of the continuous and dispersed phase liquids through the microfluidic droplet generator. The multi-hollow polyimide aerogel particles obtained after supercritical drying of the gel particles present mesopores, high BET surface area, and excellent prospect for thermal insulation.

scholarly journals Study on the growth rate of natural gas hydrate in water-in-oil emulsion system using a high-pressure flow loop

RSC Advances ◽  
2018 ◽  
Vol 8 (64) ◽  
pp. 36484-36492 ◽  
Author(s):  
Xiaofang Lv ◽  
Bohui Shi ◽  
Shidong Zhou ◽  
Haoping Peng ◽  
Yun Lei ◽  
...  
Keyword(s):  
Growth Rate ◽  
High Pressure ◽  
Focal Point ◽  
Emulsion System ◽  
Natural Gas Hydrate ◽  
Flow Loop ◽  
Oil Emulsion ◽  
Water Pipelines ◽  
Slurry Transport ◽  
Water In Oil Emulsion

Hydrate slurry transport technology in deep-water pipelines has become a focal point among worldwide researches, due to its high economic efficiency.

Study on Propylene Recovery in a Dispersed Absorption System-(Water-in-Oil) Emulsion System

2011 ◽  
Vol 383-390 ◽  
pp. 6151-6155
Author(s):  
Hong Jing Liu ◽  
Ying Zhang ◽  
Hui Yao ◽  
Wei Zhao
Keyword(s):  
Droplet Size ◽  
Absorption Rate ◽  
Volume Fraction ◽  
Dispersed Phase ◽  
Emulsion System ◽  
Absorption System ◽  
Oil Emulsion ◽  
Stirring Rate ◽  
Water In Oil Emulsion ◽  
System Water

The purpose of the paper is to investigate propylene recovery by a new absorption system, namely water-in-oil emulsion absorbent. Water in oil emulsion, in which kerosene used as oil phase with dispersed water droplet, is prepared to be as absorbent to absorb propylene. The effect of volume fraction dispersed phase, dispersed droplet size, and the stirring rate on propylene absorption rate are researched. Experimental results indicate that the absorption rate of propylene can increase 20% compared with traditional absorption method. The volume fraction dispersed phase should be appropriate, otherwise the enhancement absorption can not be attained. The appropriate number is 0.05 for this dispersion. The smaller droplet size of dispersed phase as well as the faster stirring rate can increase the propylene absorption rate. The mechanism of enhancement propylene absorption is attributed to the intensive turbulence in boundary layer between gas and liquid due to the movement of dispersed water droplets.

scholarly journals Preparation and Properties of SiBCO Aerogel and Its Composites

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 40 ◽  
Author(s):  
Xiafei Li ◽  
Junzong Feng ◽  
Jie Yin ◽  
Yonggang Jiang ◽  
Jian Feng
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Thermal Insulation ◽  
Phenylboronic Acid ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Supercritical Drying ◽  
Temperature Resistance ◽  
Mullite Fiber ◽  
Boron Source

To obtain new high-temperature resistant composites that can meet the requirements of aircraft development for thermal insulation and mechanical properties, SiBCO aerogel composites were prepared by sol-gel, supercritical drying and high-temperature pyrolysis with trimethyl borate (TMB) or phenylboronic acid (PBA) as the boron source and mullite fiber as reinforcement. The structure and composition of the SiBCO aerogel and its composites were characterized with SEM, FT-IR, ICP and nitrogen adsorption tests. The specific surface area of the SiBCO aerogel is 293.22 m2/g, and the pore size is concentrated in the range of 10–150 nm. The mechanical properties, the thermal insulation properties and the temperature resistance were also studied. Due to the introduction of boron, the temperature resistance of SiBCO aerogel composites is improved greatly, and the service temperature of composites reached 1773 K. When n (TMB)/n (TEOS) = 1/1, the temperature resistance of the composites is the best. After heating in air at 1773 K for 30 min, the shrinkage of SiBCO aerogel composites is only 2.45%, and the thermal conductivity of the composites is 0.138 W/(m·K) at 1773 K. In addition, the type and amount of catalyst also have certain effects on the mechanical properties and temperature resistance of the composites.

Dependence of Salt in Water-in-Crude-Oil Emulsion System

2005 ◽  
Vol 47 (92) ◽  
pp. 255 ◽  
Author(s):  
Park Jong-Ho ◽  
Back Nam Gwon ◽  
Yang Ho-Soon ◽  
Choi Byung-Chun ◽  
Kim Jeong-Bae ◽  
...  
Keyword(s):  
Crude Oil ◽  
Emulsion System ◽  
Oil Emulsion

Crystal engineering on superpolyhedral building blocks in metal–organic frameworks applied in gas adsorption

2015 ◽  
Vol 71 (6) ◽  
pp. 613-618 ◽  
Author(s):  
Ying-Pin Chen ◽  
Tian-Fu Liu ◽  
Stephen Fordham ◽  
Hong-Cai Zhou
Keyword(s):  
Surface Area ◽  
Crystal Engineering ◽  
Gas Adsorption ◽  
Metal Organic Frameworks ◽  
Supercritical Drying ◽  
Building Blocks ◽  
Structural Features ◽  
Open Channels ◽  
Bet Surface Area ◽  
Metal Organic

Two metal–organic frameworks [PCN-426(Ni) and PCN-427(Cu)] have been designed and synthesized to investigate the structure predictability using a SBB (supermolecular building blocks) approach. Tetratopic ligands featuring 120° angular carboxylate moieties were coordinated with a [Ni3(μ3-O)] cluster and a [Cu2O2] unit, respectively. As topologically predicted, 4-connected networks with square coordination adopted the nbo net for the Ni-MOF and ssb net for the Cu-MOF. PCN-426(Ni) was augmented with 12-connected octahedral SBBs, while PCN-427(Cu) was constructed with tetragonal open channels. After a CO2 supercritical drying procedure, the PCN-426(Ni) possessed a Brunauer–Emmett–Teller (BET) surface area as high as 3935 m2 g−1 and impressively high N2 uptake of 1500 cm3 g−1. This work demonstrates the generalization of the SBB strategy, finding an alternative to inconvenient synthetic processes to achieve the desired structural features.

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