Şadiye Şener

Zirconium tetra-n-butylate modified with different organic acids: Hydrolysis and polymerization of the products

In this work, (a) complexation reaction of zirconium tetra-n-butylate, Zr(OBun)4, with MAc and different organic acids, (b) the hydrolysis reaction of modified Zr species, and (c) the polymerization reaction of complex products are studied. Zr(OBun)4 was reacted with different mole ratios of methacrylic acid (MAc) at room temperature and the maximum combination ratio was found to be 1:2 [Zr(OBun)4:MAc] by FT-IR. The modification of zirconium tetra-n-butylate with the acid mixtures [methacrylic acid-acetic acid (MeCOOH), methacrylic acid-propionic acid (EtCOOH), methacrylic acid-butyric acid (PrCOOH)] was made for a combination ratio of 1:1:1 [MAc:RCOOH:Zr(OBun)4; R: Me, Et, Pr] and the products were characterized by1H-NMR, FT-IR, and UV spectroscopies. Following their synthesis, hydrolysis of the complexes with various amounts of water and polymerization with benzoyl peroxide were realized. The hydrolysis and polymerization products of the complexes were studied by Karl-Fischer coulometric titration and thermal analysis, respectively. Methyl ethyl ketone(MEK) and chloroform were chosen as solvents.

NEW PHOSPHORYLATED DERIVATIVES OF PIPERIDINE AND PYRROLIDINE

Abstract Phosphorylation reactions of piperidine and pyrrolidine with dialkylchlorophosphates are described. Expected products are obtained in good yields at room temperature.

Removal of Inorganic–Organic Bound Cu(II) from Different Aqueous Solutions by New Adsorbents Synthesized by Sol–Gel Process

Abstract Hydrolysis product of alcohol modified titanium(IV)‐n‐propoxide and its coated form were prepared as new and regenerable adsorbents for adsorbing and removing Cu(II) ions from its different aqueous solutions. The hydrolysis and alcoholysis products and adsorbents were characterized using GC, 1H‐NMR, FT‐IR, SEM, and TG‐DTA analysis. It was found that Cu(II) ion adsorption rather increased when hydrolysis product of alcohol modified titanium(IV)‐n‐propoxide was coated with prehydrolyzed 3‐mercaptopropyltrimethoxy silane in n‐propanol and this coated material was used as adsorbent. Depending on the results of experiments performed at optimum conditions of initial Cu(II) concentration, amount of adsorbent, contact time, and pH, maximum adsorption of Cu(II), i.e., >98% has been achieved under the non‐competitive conditions, while almost 60% is achieved under the competitive conditions of Pb(II), Zn(II), Fe(III), and alkali and earth alkali metals. It was also concluded that Cu(II) adsorption efficiency is not affected from the media containing acetate, tannic acid, or Turkish Blue dye. The adsorbent was easily regenerated with 5 N HNO3 solution and used over and over again for the adsorption of Cu(II) ions.

Natural Pyrophyllite and M(OR)x Based MxOy Powders as New Adsorbents for Heavy Metal Adsorption

Heat treated hydrolysis-condensation products of aluminiumtri-sec-butoxide (Al(OBu s )3) and alcohol modified Al(OBu s )3 were synthesised by sol-gel process. These synthetic powders, natural pyrophyllite and their 3-mercaptoprophyltrimethoxysilane coated forms were utilised as adsorbents for the removal of Cu(II) ions from aqueous solutions. The adsorption increased when natural and synthetic powders coated with SH-Si were used. It was concluded that the dried powders obtained from the hydrolysis-condensation product of Al(OBu s )3 and its alcohol modified form, and coated pyrophyllite would substitute for Amberlite IR 120 Na form resin. Introduction The disposal of heavy metals by wastewaters has been considered as one of the most important environmental problem [1]. There are numerous examples of reports on water pollution and the majority agrees to adsorb the heavy metals on adsorbents to cope with this problem [2]. Clays are low cost adsorbents for organic molecules but they can not be used to adsorb toxic heavy metals without modification. On the other hand, when the clay surface is modified with organo-functional silanes, the surface gains perfect properties to remove toxic organic and heavy metals, depending on the type of functional silane [3]. Metal oxides obtained from the metal alkoxides by sol-gel process, and their forms coated with organo-functional silanes are also novel adsorbents for adsorption of toxic contaminants from aqueous solutions. Erdemoğlu et al. and Sayılkan et al. [4,5] synthesized new adsorbents by the hydrolysis-condensation reaction of titanium-n-propoxide, zirkonium-npropoxide and titanium etoxide and they coated the synthetic ZrO2 and TiO2 powders with amino-, mercaptoand epoxy functional silanes to prepare adsorbents for removal of Cu 2+ , Pb 2+ , Fe 3+ , aniline and phenol from aqueous solutions. In this study, it was aimed to develop novel and efficient adsorbent powders by using sol-gel process techniques and to utilise these powders as adsorbents for the removal of Cu(II) ions from aqueous solutions. The results of adsorption experiments were compared with Amberlite IR 120 Na form commercial resin (IR120). Materials and Methods Materials Pyrophyllite is a hydrous aluminium silicate mineral with the chemical formula of Al2Si4O10(OH)2. The pyrophyllite sample consisting of 28% Al2O3, 66.2% SiO2 and 4.27% loss on ignition at 1000°C was obtained from Malatya-Pütürge region of Turkey. Al(OBu s )3 was used as precursor to prepare synthetic powders. 3-mercaptoprophyltrimethoxysilane was used as coupling agent. 2Butoxyethanol (2-BuOEtOH) was used as modifier for Al(OBu s )3. Methyl iso-butyl keton (MIBK) and methanol used as solvents were stored over molecular sieve (Fluka, 3ÅXL8) for a day before use. Analytical grade Cu(NO3)2 were used to prepare Cu(II) solutions. Key Engineering Materials Online: 2004-05-15 ISSN: 1662-9795, Vols. 264-268, pp 2239-2242 doi:10.4028/www.scientific.net/KEM.264-268.2239