Researcher:
Nozari, Vahid

Profile Picture
ORCID

Job Title

Master Student

First Name

Vahid

Last Name

Nozari

Name

Name Variants

Nozari, Vahid

Email Address

Birth Date

Filters

2017 - 20194

Advanced Search

Filter by

Settings

Researcher Of Publications: search.filters.isAuthorOfPublication.d168ed17-e132-456d-902d-74957cc53e2f

Search Results

Now showing 1 - 4 of 4
  • Placeholder
    PublicationMetadata only
    Structural factors determining thermal stability limits of ionic liquid/mof composites: imidazolium ionic liquids combined with cuBTC and ZIF-8
    (Amer Chemical Soc, 2019) N/A; N/A; Department of Chemical and Biological Engineering; Department of Chemical and Biological Engineering; Zeeshan, Muhammad; Nozari, Vahid; Keskin, Seda; Uzun, Alper; PhD Student; N/A; Faculty Member; Faculty Member; Department of Chemical and Biological Engineering; Graduate School of Sciences and Engineering; N/A; College of Engineering; College of Engineering; N/A; N/A; 40548; 59917
    Twenty-nine different imidazolium ionic liquids (ILs) were combined with two different metal-organic frameworks (MOFs), ZIF-8 and CuBTC, and the resulting IL/MOF composites were characterized in detail by combining X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), and Fourier transform infrared (FTIR) spectroscopy. Characterization data illustrated that MOFs remained structurally intact upon combining them with ILs. Thermogravimetric analysis performed on IL/MOF composites showed that most of the composites have lower thermal stabilities compared to the bulk ILs and pristine MOFs, whereas composites with ILs having a functional group in their anions showed thermal stability limits higher than those of bulk ILs. The derivative onset temperatures representing the maximum tolerable temperatures of the composites were analyzed based on the structural differences in MOFs and ILs, such as the changes in the alkyl chain length, methylation on the C2 site, and functionalization of the cation and the size/electronic changes on the anion. Data illustrated that the maximum tolerable temperatures of IL/MOF composites decrease with an increase in the alkyl chain length on the IL's imidazolium ring. Substitution of the alkyl group with functionalized groups in the IL's imidazolium ring also led to a decrease in the maximum tolerable temperatures of the composites. VVhereas, fluorination of the anion resulted in an increase in the thermal stability limits of the corresponding IL/MOF composites. Furthermore, ILs having a dicyanamide, acetate, and phosphate anion also showed an increase in their maximum tolerable temperatures when combined with CuBTC compared to their bulk counterparts. Moreover, simple structural descriptors for each cation and anion were defined by means of the density functional theory (DFT) calculations and used in the quantitative structure-property relationship (QSPR) analysis to correlate the maximum tolerable temperatures of IL/MOF composites to the IL's cation and anion structure. Results presented in this study will provide a guideline for the selection of proper IL-MOF pairs according to the application temperature of IL/MOF composites in various fields.
  • Thumbnail Image
    PublicationOpen Access
    Effect of methylation of ionic liquids on the gas separation performance of ionic liquid/metal-organic framework composites
    (Royal Society of Chemistry (RSC), 2018) Department of Chemical and Biological Engineering; Nozari, Vahid; Keskin, Seda; Uzun, Alper; Zeeshan, Muhammad; Faculty Member; PhD Student; Department of Chemical and Biological Engineering; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Graduate School of Sciences and Engineering; N/A; 40548; 59917; N/A
    1-N-Butyl-3-methylimidazolium hexafluorophosphate, [BMIM]ijPF6], and its methylated form, 1-N-butyl2,3-dimethylimidazolium hexafluorophosphate, [BMMIM]ijPF6], were incorporated into CuBTC to examine the effect of methylation of ionic liquids (ILs) on the gas separation performance of the corresponding IL/ metal–organic framework (MOF) composites. Spectroscopic analysis revealed that the interactions of the methylated ILs with CuBTC were weaker compared to those of its non-methylated counterpart. Gas uptake measurements illustrated that this difference in the interactions influences the gas separation performance of the composites. Accordingly, the CO2/N2: 15/85 and CH4/N2: 50/50 selectivities increased by 37% and 60% for [BMMIM]ijPF6]/CuBTC and 34% and 50% for [BMIM]ijPF6]/CuBTC, respectively, compared to the corresponding selectivities of pristine CuBTC at 1000 mbar. The results revealed another structural parameter controlling the performance of the IL/MOF composites, a novel type of material with rapidly expanding application areas.
  • Thumbnail Image
    PublicationOpen Access
    Core-shell type ionic liquid/metal organic framework composite: an exceptionally high CO2/CH4 selectivity
    (American Chemical Society (ACS), 2018) Işık, Tuğba; Ortalan, Volkan; Department of Chemical and Biological Engineering; Nozari, Vahid; Yağcı, Mustafa Barış; Ünal, Uğur; Keskin, Seda; Uzun, Alper; Zeeshan, Muhammad; Researcher; Faculty Member; Faculty Member; PhD Student; Department of Chemical and Biological Engineering; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Graduate School of Sciences and Engineering; N/A; N/A; 42079; 40548; 59917; N/A
    Here, we present a new concept of a core-shell type ionic liquid/metal organic framework (IL/MOF) composite. A hydrophilic IL, 1-(2-hydroxyethyl)-3-methylimidazolium dicyanamide, [HEMIM][DCA], was deposited on a hydrophobic zeolitic imidazolate framework, ZIF-8. The composite exhibited approximately 5.7 times higher CO2 uptake and 45 times higher CO2/CH4 selectivity at 1 mbar and 25 degrees C compared to the parent MOF. Characterization showed that IL molecules deposited on the external surface of the MOF, forming a core (MOF)-shell (IL) type material, in which IL acts as a smart gate for the guest molecules.
  • Thumbnail Image
    PublicationOpen Access
    Toward rational design of ionic liquid/metal-organic framework composites: effects of interionic interaction energy
    (American Chemical Society (ACS), 2017) Department of Chemical and Biological Engineering; Nozari, Vahid; Keskin, Seda; Uzun, Alper; Faculty Member; Department of Chemical and Biological Engineering; Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); College of Engineering; Graduate School of Sciences and Engineering; College of Sciences; N/A; 40548; 59917
    One of the structural factors controlling the extent of interactions between ionic liquids (ILs) and metal-organic frameworks (MOFs) in IL/MOF composites is elucidated. Results showed that the thermal stability limits and adsorption performances of the IL/MOF composites can be tuned by the interionic interaction energy of bulk ILs, which can be probed spectroscopically via C2H infrared stretching frequency.