Characterization of the porous structure of biodegradable scaffolds obtained with supercritical CO2 as foaming agent

2007 ◽  
Vol 15 (4) ◽  
pp. 397-403 ◽  
Author(s):  
Angélique Léonard ◽  
Cedric Calberg ◽  
Greet Kerckhofs ◽  
Martine Wevers ◽  
Robert Jérôme ◽  
...  
2020 ◽  
Vol 17 (2) ◽  
pp. 177
Author(s):  
Istikamah Subuki ◽  
Suffiyana Akhbar ◽  
Farrah Khalidah Nor Wahid

This study is aimed to investigate the characteristics of the composite containing blended poly (ɛ-caprolactone) (PCL), hydroxyapatite (HA) and thermoplastic zein (TZ). Thermoplastic zein was developed by mixing zein with glycerol (GLY) and polyethylene glycol (PEG). The thermal characterization of mixed TZ and bio composite was characterized in order to investigate the characterization of PCL/TZ/HA composites. The bio composited was then moulded and produce porous structure via solid state supercritical carbon dioxide (scCO2) foaming process. The specimen was saturated with CO2 for 6 hours at 50˚C and saturation pressure of 20MPa at high depressurization rate. The morphology of porous specimen produced were characterized by scanning electron microscopy (SEM). The results indicated that after polymer saturation with CO2, high depressurization causes the formation of nucleated gas cells that give rise to pores within the foamed specimens. The blended bio composite with composition of PCL60/TZ20/HAp20 exhibit well interconnected porous structure compared to other bio composite prepared. The foaming effect produce foams with heterogeneous morphologies on bio composite material at relatively low temperature.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1301
Author(s):  
Zully J. Suárez Montenegro ◽  
Gerardo Álvarez-Rivera ◽  
Jose A. Mendiola ◽  
Elena Ibáñez ◽  
Alejandro Cifuentes

This work reports the use of GC-QTOF-MS to obtain a deep characterization of terpenoid compounds recovered from olive leaves, which is one of the largest by-products generated by the olive oil industry. This work includes an innovative supercritical CO2 fractionation process based on the online coupling of supercritical fluid extraction (SFE) and dynamic adsorption/desorption for the selective enrichment of terpenoids in the different olive leaves extracts. The selectivity of different commercial adsorbents such as silica gel, zeolite, and aluminum oxide was evaluated toward the different terpene families present in olive leaves. Operating at 30 MPa and 60 °C, an adsorbent-assisted fractionation was carried out every 20 min for a total time of 120 min. For the first time, GC-QTOF-MS allowed the identification of 40 terpenoids in olive leaves. The GC-QTOF-MS results indicate that silica gel is a suitable adsorbent to partially retain polyunsaturated C10 and C15 terpenes. In addition, aluminum oxide increases C20 recoveries, whereas crystalline zeolites favor C30 terpenes recoveries. The different healthy properties that have been described for terpenoids makes the current SFE-GC-QTOF-MS process especially interesting and suitable for their revalorization.


2012 ◽  
Vol 262 ◽  
pp. 405-409
Author(s):  
Yang Liu ◽  
Shan Shan Li ◽  
Xin Yan Yang ◽  
Chong Xing Huang

A new-type foam composites were fabricated by baking method from a mixture of cassava starch. A central composite design was constructed using the software Statistics Analysis System 9.0 to evaluate the static compression stress of foamed material. The optimum dosages of adhesive, foaming agent, catalyst were 2.0g, 6.0g, 2.4g, respectively; reaction temperature 65°C; reaction time 16 hour.


2019 ◽  
Vol 25 (4) ◽  
pp. 43-49
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE ◽  
ANA CASANDRA SEBE

The paper presents an aluminum foam experimental technique using the microwave energy. The raw material was recycling aluminum waste processed by ecological melting and gas atomizing to obtain the fine powder required in the foaming process. The powder mixture was completed with dolomite as a foaming agent. The products had a fine and homogeneous porous structure (pore size between 0.4-0.9 mm). The density (1.17-1.19 g/cm3), the compressive strength (6.83-7.01 MPa) and the thermal conductivity (5.71-5.84 W/m·K) had values almost similar to the foams made by conventional methods.


2021 ◽  
Vol 316 ◽  
pp. 153-158
Author(s):  
Boris M. Goltsman ◽  
Lyubov A. Yatsenko ◽  
Natalia S. Goltsman

The article discusses the peculiarities of the "water-glass – glycerol" foaming mixture components interaction during foam glass synthesis. The important role of the foaming additive type in the foam glass porous structure formation was described, the main foaming substances were listed. The obtaining and researching technology of the samples was described, the compositions of the initial batches using the "water-glass – glycerol" mixture were developed. It was shown that a material with a highly porous structure and density below 500 kg/m3 can be obtained only with the combined introduction of water-glass and glycerol. In this case, mixtures with a predominance of water-glass in the foaming mixture possess optimal properties. Using DSC, it was shown that the addition of water-glass to the mixture completely eliminates the evaporation of glycerol at lower temperatures and intensifies its combustion at higher temperatures. Thus, the addition of water-glass to the glycerol-based foam glass batch allows glycerol to be saved up to higher temperatures that increases the resulting material porosity.


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