Synthesis of Nano/Microsized MIL-101Cr Through Combination of Microwave Heating and Emulsion Technology for Mixed-Matrix Membranes

Abstract

Nano/microsized MIL-101Cr was synthesized by microwave heating of emulsions for the use as a composite with Matrimid mixed-matrix membranes (MMM) to enhance the performance of a mixed-gas-separation. As an example, we chose CO2/CH4 separation. Although the incorporation of MIL-101Cr in MMMs is well-known, the impact of nanosized MIL-101Cr in MMMs is new and shows an improvement compared to microsized MIL-101Cr under the same conditions and mixed-gas permeation. In order to reproducibly obtain nanoMIL-101Cr microwave heating was supplemented by carrying out the reaction of chromium nitrate and 1,4-benzenedicarboxylic acid in heptane-in-water emulsions with the anionic surfactant sodium oleate as emulsifier. The use of this emulsion with the phase inversion temperature (PIT) method offered controlled nucleation and growth of nanoMIL-101 particles to an average size of <100 nm within 70 min offering high apparent BET surface areas (2,900 m2 g−1) and yields of 45%. Concerning the CO2/CH4 separation, the best result was obtained with 24 wt.% of nanoMIL-101Cr@Matrimid, leading to 32 Barrer in CO2 permeability compared to six Barrer for the neat Matrimid polymer membrane and 21 Barrer for the maximum possible 20 wt.% of microMIL-101Cr@Matrimid. The nanosized filler allowed reaching a higher loading where the permeability significantly increased above the predictions from Maxwell and free-fractional-volume modeling. These improvements for MMMs based on nanosized MIL-101Cr are promising for other gas separations.

Coordination modulation: a way to improve the properties of metal–organic frameworks

“…The use of this emulsion with the phase inversion temperature (PIT) method offered the controlled nucleation and growth of nanoMIL-101 particles with an average size of less than 100 nm in 70 min, resulting in a high BET surface areas (2900 m 2 g −1 ) and a yield of 45%. 125 Phase inversion refers here to the conversion of oil-in-water to water-in-oil emulsion, which is achieved by carrying out the reaction at a temperature at which the phase transition occurs.…”

A novel test device and quantitative colorimetric method for the detection of human chorionic gonadotropin (hCG) based on Au@Zn–salen MOF for POCT applications

“…46–49 These materials are currently receiving a lot of attention because of the many different ways in which they can be used, as well as their excellent thermal and chemical stability, high surface area, and manageable pore size. 50–59…”

“…[46][47][48][49] These materials are currently receiving a lot of attention because of the many different ways in which they can be used, as well as their excellent thermal and chemical stability, high surface area, and manageable pore size. [50][51][52][53][54][55][56][57][58][59] This work involved the synthesis of a novel gold-zinc-salenbased-MOF (Au-Zn-Sln-MOF) composite by reacting Zn(NO 3 ) 2 -$6H 2 O and HAuCl 4 $3H 2 O at a molar ratio of 1 : 1 utilizing an organic nano linker previously prepared by Sheta et al 60 Microanalytical and spectral methods such HR-TEM, FE-SEM, EDX, XRD, elemental analysis, FT-IR, UV-vis, and TGA/DSC were used to characterize the synthetic Au-Zn-Sln-MOF composite. The current research went further by using the Au-Zn-Sln-MOF composite as a promising biosensor for detecting and quantifying hCG hormone at ultra-low concentrations, using both strip devices for qualitative detection and a colorimetric approach for quantication, both of which yielded statistically validated acceptable results.…”

Selective and Fast Detection of Fluoride-Contaminated Water Based on a Novel Salen-Co-MOF Chemosensor

“…MOFs are a family of organic–inorganic hybrid structures, which are formed via coordination bonding between functionalized linkers and the center of metal ions, have many unique properties, and are used in a huge number of vital applications. − …”