Wyniki wyszukiwania - BazTech

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Application of porogenes in production of porouspolymers by supercritical foaming

Sawicka Katarzyna, Kosowska Katarzyna, Henczka Marek

Chemical and Process Engineering

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2019

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Vol. 40, nr 1

115–-122

EN

Biocomposite foam scaffolds of poly(ε-caprolactone) (PCL) with different porogenes were producedwith batch foaming technique using supercritical carbon dioxide (scCO2)as a blowing agent. Inperformed experiments composites were prepared from graphene-oxide (nGO), nano-hydroxyapatite(nHA) and nano-cellulose (nC), with various concentrations. The objective of the study was to explorethe effects of porogen concentration and foaming process parameters on the morphology and me-chanical properties of three-dimensional porous structures that can be used as temporary scaffolds intissue engineering. The structures were manufactured using scCO2as a blowing agent, at two variousfoaming pressures (9 MPa and 18 MPa), at three different temperatures (323 K, 343 K and 373 K) fordifferent saturation times (0.5 h, 1 h and 4 h). In order to examine the utility of porogenes, a number oftests, such as static compression tests, thermal analysis and scanning electron microscopy, have beenperformed. Analysis of experimental results showed that the investigated materials demonstrated highmechanical strength and a wide range of pore sizes. The obtained results suggest that PCL porousstructures are useful as biodegradable and biocompatible scaffolds for tissue engineering.

2

The influence of supercritical foaming conditions on properties of polymer scaffolds for tissue engineering

Kosowska K., Henczka M.

Chemical and Process Engineering

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2017

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Vol. 38, nr 4

535--541

EN

The results of experimental investigations into foaming process of poly(ε-caprolactone) using supercritical CO2 are presented. The objective of the study was to explore the aspects of fabrication of biodegradable and biocompatible scaffolds that can be applied as a temporary three-dimensional extracellular matrix analog for cells to grow into a new tissue. The influence of foaming process parameters, which have been proven previously to affect significantly scaffold bioactivity, such as pressure (8-18 MPa), temperature (323-373 K) and time of saturation (1-6 h) on microstructure and mechanical properties of produced polymer porous structures is presented. The morphology and mechanical properties of considered materials were analyzed using a scanning electron microscope (SEM), x-ray microtomography (μ-CT) and a static compression test. A precise control over porosity and morphology of obtained polymer porous structures by adjusting the foaming process parameters has been proved. The obtained poly(ε-caprolactone) solid foams prepared using scCO2 have demonstrated sufficient mechanical strength to be applied as scaffolds in tissue engineering.

3

Rozpuszczalniki przyszłości - ciecze jonowe i płyny nadkrytyczne

Majewska E., Białecka-Florjańczyk E.

Przemysł Spożywczy

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2011

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T. 65, nr 4

18-21

PL

Ciecze jonowe i płyny nadkrytyczne to nowa klasa rozpuszczalników o unikatowych właściwościach, dzięki którym mogą być doskonałym zamiennikiem tradycyjnych rozpuszczalników w wielu procesach technologicznych. Nie stanowią one zagrożenia dla zdrowia człowieka i środowiska naturalnego, spełniają więc wymagania zielonej chemii. Ich zastosowanie napotyka pewne bariery wynikające z wysokiej ceny w przypadku cieczy jonowych oraz instalowania kosztownej aparatury w przypadku ekstrakcji płynami nadkrytycznymi.

EN

Ionic liquids and supercritical fluids are a new class of solvents. Their unique properties make them an excellent alternative to traditional solvents in many technological processes. They pose a threat neither to human health nor to natural environment - in that way they meet the 'green chemistry' requirements. Their application meets, however, some barriers which stem from high costs, when it comes to ionic liquids, and employing high pressure equipment as well as bearing expenses on compressing solvents in the case of supercritical fluid extraction.