EVALUATION OF HYPOTHESES OFF FORMATION MECHANISMS OF POLYMERIC ASYMMETRIC POROUS MEMBRANES BY WET PHASE INVERSION
| Autor: | Poznič, Aleš |
|---|---|
| Přispěvatelé: | Stropnik, Črtomir |
| Jazyk: | slovinština |
| Rok vydání: | 2009 |
| Předmět: |
cellulose acetate
acetone membranes thickness maximal turbidity udc:544.725.2(043.2) tetrahydrofuran maksimalna motnost polimerne membrane zakasnitveni čas nastanka motnosti celulozni acetat delay time of turbidity phenomenon aceton tetrahidrofuran debelina membrane mehanizem nastanka membran membrane formation mechanism polymer membranes |
| Zdroj: | Maribor |
| Popis: | Polimerne membrane se bodo v bodoče uporabljale za separacijske postopke, ki bodo imeli veliko prednosti, kot sta na primer: nižja poraba energije in bolj selektivno ločevanje snovi. Da jih bomo lahko uporabljali, moramo v začetku poznati njihove nastanke. Mehanizem nastanka polimernih asimetričnih poroznih membran, pripravljenih po mokrem postopku fazne inverzije, je še dokaj neznan. Zaradi tega smo v diplomskem delu zbrali raziskovalne podatke za specifična sistema CA/ACE/voda in CA/THF/voda, ki so nastali v našem laboratoriju in jih podrobno analizirali. Ternarna sistema sta specifična zato, ker se pri njiju pojavlja zakasnitveni čas nastanka motnosti. To pomeni, da opazimo motnost pri nastanku membrane po pretečenem določenem času. Ta je odvisen od debeline nanosa, koncentracije polimerne raztopine in predvsem topila. Posledično je od zakasnitvenega časa nastanka motnosti odvisna debelina formirane membrane. Glede na podobnosti in razlike membrano-tvornih sistemov kot so zakasnitveni čas nastanka motnosti, naklon kota motnosti, maksimalna motnost, debelina in topilo, smo uvrstili membrano-tvorne sisteme v območja oz. tipe. Tako smo v sistemih CA/ACE/voda in CA/THF/voda odkrili različna območja obnašanja tega sistema. Kar je bil tudi cilj naše naloge. In future, polymer membranes will be used in separation processes which will have many advantages, for example: lower energy consumption and a more selective substance separation. In order to use these membranes, first we have to be familiar with the membrane formation mechanism. The formation mechanism of polymer asymmetric porous membranes prepared by the wet phase inversion process is still quite unexplored. For this reason we have collected the research results for two specific systems CA/ACE/water and CA/THF/water which we obtained in our laboratory and which we analysed in detail, and presented them in the empirical part of the thesis. Both CA/ACE/water and CA/THF/water ternary system are specific because of delay time of turbidity phenomenon which occurs in these two systems. This means that the turbidity in membrane formation is visible only after a certain lapse of time which is dependent on the thickness of the layer, and the polymer solution and solvent concentration. The thickness of formed membrane is consequently dependent on the delay time of turbidity phenomenon. Considering the similarities and differences between membrane-forming system like delay time of turbidity phenomenon, slope angle of turbidity, maximal turbidity, thickness and solvent, we have classified the membrane-forming system into areas or types. This has resulted in discovering different behaviour areas of this system in both CA/ACE/water and CA/THF/water solvent systems. What was also the aim of this thesis. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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