Sinteza i karakterizacija kompozita polianilina i metalo-organskih mrežnih struktura na bazi Zn(II)-oksidkarboksilata

Abstract

U ovoj tezi po prvi put su sintetisani kompoziti MOF-5, tipičnog predstavnika metalo-organskih mrežnih struktura (MOF), i polianilina (PANI), jednog od najvažnijih elektroprovodnih polimera. MOF-5 je mikroporozni, kristalni, elektroneprovodan materijal, velike specifične površine i poroznosti, koji se sastoji od Zn4O jedinica povezanih 1,4-benzendikarboksilatnim linkerima. PANI je konjugovani polimer koji egzistira u različitim kiselinsko-baznim i redoks oblicima i pokazuje visoku električnu provodljivost, ali ima malu specifičnu površinu. U prvom delu teze razvijena je efikasna sinteza čiste faze MOF-5, bazirana na korišćenju anhidrovanog cink acetata kao prekursora. Dodavanjem vode za in situ formiranje različitih cink acetata hidrata i karakterizacijom produkata nađeno je da optimalna količina vode za sintezu čistog kubičnog MOF-5 iznosi 0,250,5 molova vode po molu Zn2+. MOF-5 sintetisan pri molskom odnosu H2O/Zn2+ = 0,5 pokazivao je najveću specifičnu površinu SBET (1937 m2g1) i korišćen je za sinteze kompozita. PANI je sintetisan oksidativnom polimerizacijom anilina u prisustvu HCl i bez dodate kiseline. Kompoziti su okarakterisani brojnim fizičkohemijskim tehnikama. Sintetičkim postupkom, u kome je neprovodni oblik PANI rastvoren u DMF mešan sa MOF-5 u različitim masenim odnosima, dobijeni su mikroporozni kompoziti veoma velike SBET (najveća 2700 m2g1) i niske električne provodljivosti. Postupkom mehaničko-hemijske sinteze, u kome su elektroprovodni oblik PANI i MOF-5 mehanički sitnjeni u različitim masenim odnosima u prisustvu male količine hloroforma, dobijeni su mikroporozni kompoziti koji su pokazivali i elektroprovodljivost (najveća 1,0103 Scm1) i velike SBET (najveća 850 m2g-1). Kompoziti MOF-5/PANI predstavljaju obećavajuće kandidate za niz primena.

In this thesis, for the first time, composites of MOF-5, a typical representative of metal-organic network structures (MOF), and polyaniline (PANI), one of the most important electrically conductive polymers, were synthesized. MOF-5 is a microporous, crystalline, non-conductive material, with a large specific surface area and porosity, consisting of Zn4O units connected by 1,4-benzenedicarboxylate linkers. PANI is a conjugated polymer that exist in various acid-base and redox forms and exhibits high electrical conductivity, but has small specific surface. In the first part of the thesis, efficient synthesis of pure phase MOF-5 was developed, based on the use of anhydrous zinc acetate as a precursor. By adding water for in situ formation of various zinc acetate hydrates and by characterization of the products it was found that the optimal amount of water for the synthesis of pure cubic MOF-5 is 0.250.5 moles of water per mole of Zn2+. MOF-5 synthesized at the H2O / Zn2+ = 0.5 molar ratio showed the highest specific surface area SBET of 1937 m2g-1 and was used for composite syntheses. PANI was synthesized by the oxidative polymerization of aniline in the presence of HCl and without added acid. Composites are characterized by a number of physicochemical techniques. Synthetic process in which the non-conductive form of PANI dissolved in DMF was mixed with MOF-5 in different mass ratios led to microporous composites of very high SBET (maximum 2700 m2g1) and low electrical conductivity. The process of mechano-chemical synthesis, in which the conductive form PANI and MOF-5 were mechanically crushed in different mass ratios in the presence of a small amount of chloroform, led to microporous composites that showed both electrical conductivity (maximum 1.0 103 Scm1) and large values of SBET (maximum 850 m2g-1). MOF-5/PANI composites are promising candidates for a range of applications.