{"id":769,"date":"2019-06-18T08:25:08","date_gmt":"2019-06-18T06:25:08","guid":{"rendered":"http:\/\/acad-icht.tm.edu.ro\/wp\/?page_id=769"},"modified":"2019-06-18T09:28:44","modified_gmt":"2019-06-18T07:28:44","slug":"111-2","status":"publish","type":"page","link":"https:\/\/acad-icht.tm.edu.ro\/wp\/?page_id=769","title":{"rendered":"Sinteza si caracterizarea gelurilor mezoporoase de silice"},"content":{"rendered":"\n<p><a href=\"http:\/\/acad-icht.tm.edu.ro\/wp\/?page_id=789\">\u00cenapoi<\/a><\/p>\n\n\n\n<p>\n<strong>Tip proiect: Proiect de mobilit\u0103\u0163i (Rom\u00e2nia-Ungaria 2016-2018<\/strong>)\n \u00een cadrul acordului de colaborare bilateral\u0103 \u00eencheiat \u00eentre\nAcademia Rom\u00e2n\u0103 \u015fi Academia Ungar\u0103 de \u015etiin\u0163e \n<\/p>\n\n\n\n<p>\n<strong>Titlu proiect<\/strong>: Sinteza si\ncaracterizarea gelurilor mezoporoase de silice\n\n<\/p>\n\n\n\n<p>\n<strong>Director de Proiect<\/strong>,\nInstitutul de Chimie\n\u201cCoriolan Dr\u0103gulescu\u201d,\nTimisoara, Romania:Dr. Putz Ana-Maria.\n<\/p>\n\n\n\n<p>\n<strong>Director de Proiect<\/strong>,\nWigner Research Centre for Physics, Institute for Solid State\nPhysics and Optics, Hungarian Academy of Sciences: Dr. Alm\u00e1sy L\u00e1szl\u00f3<\/p>\n\n\n\n<p>\n<strong>Durata proiectului: <\/strong>3 ani (2016-2018)<\/p>\n\n\n\n<p>\n<strong>Entit\u0103\u0163ile finantatoare<\/strong>: Academia Rom\u00e2n\u0103 \u015fi Academia\nUngar\u0103 de \u015etiin\u0163e\n<\/p>\n\n\n\n<p>\n<strong>Echipa Wigner:<\/strong> Dr.\nLen Ad\u00e9l, Dr. Dud\u00e1s Zolt\u00e1n-Imre \n<\/p>\n\n\n\n<p>\n<strong>Echipa ICT: <\/strong>Dr.Cecilia Savii, Dr. Cat\u0103lin Ian\u0103\u015fi,\nDr. Sorina Ilie\u015f, Drd. Roxana Nicola, Chim. Elena-Mirela Picioru\u015f.<\/p>\n\n\n\n<p>\n<strong>Rezumatul proiectului:<\/strong><\/p>\n\n\n\n<p>\nMaterialele mezoporoase sintetizate prin templatare supramolecular\u0103\n\u015fi porozitate planificat\u0103 sunt de interes pentru dezvoltarea\nacestora pentru un domeniu larg de aplica\u0163ie, incluz\u0103ndu-l  \u015fi pe\nce de sisteme de eliberare de medicamente. Lichidele ionice sunt o\nclas\u0103 relativ nou\u0103 de agen\u0163i de templatare neconven\u0163ional\u0103,\nav\u00e2nd poten\u0163ial \u00een ob\u0163inerea de materiale mezoporoase de silice\ncu porozitate controlat\u0103. Func\u0163ie de lungimea lan\u0163ului alchilic al\nsurfactantului sau a lichidului ionic, se pot ob\u0163ine variate grade\nde ordonare. Pori ordona\u0163i cubic sau hexagonal, se ob\u0163in folosind\nagen\u0163i de templatare cu lan\u0163uri alchilice lungi, \u00een\ntimp ce lan\u0163urile alchilice scurte sau polimerii, duc la formarea\nunei structuri haotice, a porilor ce adesea prezint\u0103 astfel o\nstructur\u0103 fractal\u0103. Parametrii acestora (ce reflect\u0103 densitatea \u015fi\numplerea spa\u0163iului \u00een gelul solid) depind \u00een mare m\u0103sur\u0103 de\nprocesul de agregare folosit. Tehnicile de difrac\u0163ie prin\n\u00eempra\u015ftiere la unghi mic, fie cu neutroni fie cu raze X, sunt\nmetode importante de caracterizare a structurilor ordonate poroase,\n\u00een intervalul de mezoporozitate, folosite \u00een investigarea fazei\nsolide a structurii nanoporoase ob\u0163inute prin metoda sol-gel, \u015fi\nred\u0103 o informa\u0163ie direct\u0103 despre exponen\u0163ii fractali\ncaracteristici.  Prezentul proiect are dou\u0103 \u0163inte: \u00een primul r\u00e2nd\nob\u0163inerea de noi materiale cu porozitate croit\u0103, folosind ca \u015fi\nagen\u0163i de templatare,  diferite clase, fie de surfactan\u0163i\nconven\u0163ionali, fie de lichide ionice, \u015fi apoi s\u0103 explor\u0103m\ncapabilitatea complex\u0103 a tehnicilor de difrac\u0163ie prin \u00eempr\u0103\u015ftiere\nla unghi mic (tehnica SANS) sau a difrac\u0163iei prin \u00eempr\u0103\u015ftiere a\nrazelor X (tehnica SAXS), pentru a evalua structura materialelor\nob\u0163inute \u015fi a \u00een\u0163elege principiile \u015fi mecanismele de formare a\nporozit\u0103\u0163ii.<\/p>\n\n\n\n<p>\n<strong>Obiectivele proiectului:<\/strong><\/p>\n\n\n\n<p>(i)\nSinteza sol-gel \u015fi sono-cataliza de materiale hibride mezoporoase pe\nbaz\u0103 de silice; \n<\/p>\n\n\n\n<p>(ii)\nCaracterizarea propriet\u0103tilor lichidelor ionice entrapate \u00een\nnanopori, comparativ cu lichidele ionice simple, neentrapate, prin\nspectroscopie IR \u015fi analiz\u0103 termic\u0103;<\/p>\n\n\n\n<p>\n. \n<\/p>\n\n\n\n<p>(iii)\nCaracterizarea structural\u0103 a materialelor de silice mezoporoas\u0103\nob\u0163inut\u0103, fie prin metode de laborator tradi\u0163ionale, precum:\nmicroscopia electronic\u0103, metoda adsorb\u0163iei-desorb\u0163iei cu azot,\nXRD, etc. \n<\/p>\n\n\n\n<p>\n(iv) Investigarea morfologiei\nsilicei mezoporoase ob\u0163inute, \u00een special a gradului de ordonare al\nporilor, folosind tehnicile SANS \u015fi SAXS. Sarcinile sunt \u00eemp\u0103r\u0163ite\n\u00eentre cele dou\u0103 laboratoare, precum urmeaz\u0103: echipa din Rom\u00e2nia\nse ocup\u0103 de sinteza materialelor \u015fi de o parte din caracterizarea\nfizico-chimic\u0103, \u00een timp ce echipa din Ungaria se ocup\u0103 de\ncaracterizarea structural\u0103 folosind metodele de difrac\u0163ie (cu\nneutroni sau cu electroni prin \u00eempra\u015ftiere la unghi mic).\nInvestiga\u0163iile de microscopie electronic\u0103, se vor realiz\u0103 \u00een\nlaboratoare din ambele \u0163\u0103ri.<\/p>\n\n\n\n<p>\n<strong>Rezultatele proiectului<\/strong>: \n<\/p>\n\n\n\n<p>\n<strong>Sinteza de silice mezoporoas\u0103\nfolosind lichide ionice <\/strong><strong>(IL)<\/strong><strong>piridinice \u015fi\nimidazolice <\/strong>\n<\/p>\n\n\n\n<p>\n \u00cen aceste sinteze am folosit ca\n\u015fi precursor pentru silice, al\u0103turi de tetraetoxisilan\n(TEOS), trimetoxisilanul\n(MTMS-ul), tetrafluoroboratul de N-butil-3-methilpiridin\u0103\n([bmPy][BF<sub>4<\/sub>])\nca \u015fi cosolvent \u015fi agent de templare, p\u0103str\u00e2nd constant raportul\nmolar al reactan\u0163ilor \u015fi variing concentra\u0163ia de lichid ionic\nfolosit \u00een sintez\u0103.  Alte serii de matrici de silice au fost\nob\u0163inute prin metoda so-gel \u00een cataliz\u0103 acid\u0103, folosind numai\nTEOS-ul ca \u015fi precursor de silice, \u015fi tetrafluoroboratul de\n1-butil-3-metilimidazol\n[BMIM][BF<sub>4<\/sub>]\npentru o serie de sinteze \u015fi clorura de 1-butil-3-metilimidazol\n([BMIM][Cl]) pentru o a\ndoua serie de sinteze, folosind un raport molar constant pentru\nceilal\u0163i reactan\u0163i \u015fi variind-se doar concentra\u0163ia de IL. Probele\nau fost caracterizate at\u00e2t \u00een forma de xerogel c\u00e2t \u015fi \u00een forma\ncalcinat\u0103, iar morfologia acestora \u00een ceea ce prive\u015fte porozitatea\n\u015fi structura s-au determinat folosind metodele SANS, a adsorb\u0163iei\ndesorb\u0163iei cu azot, IR \u015fi analiza termogravimetric\u0103. Pentru a\ninvestiga stabilitatea termic\u0103 a materialelor, s-a folosit metoda\nanalizei termogravimetrice. \u00cen timpul tratamentului termic,\ndescompunerea IL entrapat \u00een matricea de silice, \u00eencepe cu 100\u00baC\nmai devreme comparativ cu IL simplu. \u00centr-un prim studiu am\ndemostrat c\u0103 ad\u0103ugarea de mici cantit\u0103\u0163i de IL \u00een mediul de\nreac\u0163ie, duce la \u00eencetinirea reac\u0163iei de policondensare \u015fi duce\nla formarea de particule de m\u0103rimi mai mari. Mai departe, am variat\nconcentra\u0163iile de IL \u00eentr-un interval \u015fi mai larg, dorind s\u0103\nob\u0163inem o compozi\u0163ie, posibil optim\u0103, pentru a ob\u0163ine o\nporozitate \u015fi mai ridicat\u0103 \u015fi o distribu\u0163ie \u00eengust\u0103 a m\u0103rimii\nporilor. Informa\u0163iile\nob\u0163inute din SANS au redat morfologia \u015fi au demostrat efectul de\ncatalizator al IL c\u00e2t \u015fi cel de agent de templatare. Din curbele\nSANS a celor dou\u0103 serii de probe imidazolice, a rezultat c\u0103 cele\ndou\u0103 IL produc structuri marcant diferite \u00een xerogelurile\nrezultate. Cel mai\nhidrofob dintre cele dou\u0103 lichide ionice folosite, [BMIM][BF<sub>4<\/sub>],\nd\u0103 o aparen\u0163\u0103 de neomogenitate cu o m\u0103rime caracteristic\u0103 de\n5-10 nm, \u00een timp ce cel mai hidrofil dintre acestea, \u015fi anume,\n[BMIM][Cl] produce structuri mai omogene, la aceast\u0103 lungime de\nscal\u0103, \u015fi sunt prezen\u0163i numai pori mari \u015fi agregate\ncaracteristice xerogelurilor simple rezultate   din TEOS, cu m\u0103rimi\ncaracteristice de peste 50 nm. Aceast\u0103 informa\u0163ie, al\u0103turi de alte\nmetode caracterizare, ne permit s\u0103 croim fin propriet\u0103\u0163ile\nmaterialelor, \u00een ceea ce prive\u015fte porozitatea, stabilitatea \u015fi\nvaliditatea pentru aplica\u0163ii ulterioare ca \u015fi sisteme de eliberare\nde medicamente. Propriet\u0103\u0163ile\nfizico-chimice ale IL se schimb\u0103 \u00een urma entrap\u0103rii \u00een nanopori,\ndatorit\u0103 interac\u0163iei cationilor\/anionilor lichidelor ionice\ncu pere\u0163ii porilor. Aplicarea acestor metode de difrac\u0163ie\nfaciliteaz\u0103 \u00een\u0163elegerea mecanismelor form\u0103rii gelurilor, \u015fi ne\nvor ajuta \u00een selectarea de condi\u0163ii potrivite de sintez\u0103, pentru\ncontrolarea porozit\u0103\u0163ii. \n<\/p>\n\n\n\n<p>\n<strong>Publica\u0163ii:<\/strong><\/p>\n\n\n\n<p>\nPutz<sup>\n<\/sup>A.M.,  Len A.,\nIan\u0103\u015fi C.<sub>, <\/sub>Savii\nC., Alm\u00e1sy L., Ultrasonic\npreparation of mesoporous silica using pyridinium ionic liquid,\nKorean J. Chem. Eng. 33 (3) 749-754, 2016.<\/p>\n\n\n\n<p>\nPutz A.M., Wang K., Len A.,\nPlocek J., Bezdicka P., Kopitsa G. P., Khamova T. V., Ian\u0103\u015fi C.,\nS\u0103c\u0103rescu L., Mitr\u00f3ov\u00e1 Z., Savii C., Yan M., Alm\u00e1sy\nL.,Mesoporous silica obtained with methyltriethoxysilane as\nco-precursor in alkaline medium, Appl. Surf. Sci., 424(3) 275-281,\n2017.<\/p>\n\n\n\n<p>\nAlm\u00e1sy L., Putz\nA.M., Len A., Plestil J., Savii C., Small-angle scattering\ninvestigation of silica xerogels and sonogels prepared with ionic\nliquid pyridinium tetrafluoroborate, Proc. Appl. Ceram. 11(3)\n229-233, 2017.<\/p>\n","protected":false},"excerpt":{"rendered":"\u00cenapoi Tip proiect: Proiect de mobilit\u0103\u0163i (Rom\u00e2nia-Ungaria 2016-2018) \u00een cadrul acordului de colaborare bilateral\u0103 \u00eencheiat \u00eentre Academia Rom\u00e2n\u0103 \u015fi Academia Ungar\u0103 de \u015etiin\u0163e Titlu proiect: Sinteza si caracterizarea gelurilor mezoporoase de silice Director de Proiect, Institutul de Chimie \u201cCoriolan Dr\u0103gulescu\u201d, Timisoara, Romania:Dr. Putz Ana-Maria. 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