Enhancing the stability of metal–organic frameworks in humid air by incorporating water repellent functional groups

Abstract

We report a modular construction of a new metal-organic framework (MOF) by strategically incorporating a number of water repellent functional groups in the frameworks. These MOFs demonstrate both open structure for high sorption capability and strong water resistance.

Function-led design of new porous materials

“…The hydrolytic stability of MOFs has since been greatly improved using design strategies such as hydrophobic organic linkers (80) or postsynthetic modification with diazo groups (81). UiO-66 and its derivatives were shown to retain their structural stability after immersion in water and 0.1 M HCl solutions; HKUST-1 (Cu-BTC) is waterstable under certain conditions but degrades at higher relative humidities and/or temperatures [90% relative humidity (RH) at 298 K] (82).…”

Emerging adsorptive removal of azo dye by metal–organic frameworks

“…One of the most important barriers to applying several types of MOFs in practical applications is related to their instability in water (Low et al, 2009;Canivet et al, 2014). Several investigations have been conducted to enhance the stability of MOFs in water (Wu et al, 2010;Yang et al, 2011a;Taylor et al, 2012) and this problem has been solved for some selected MOFs.…”

Tuning the Moisture and Thermal Stability of Metal–Organic Frameworks through Incorporation of Pendant Hydrophobic Groups

“…26 This is a significant concern in clean energy technologies, as water is certainly present in flue gas, and is often an impurity in natural gas supplies. To this end, a number of researchers have investigated methods for enhancing the water stability of MOFs, including using high oxidation state metals (such as Fe 3+ , Al 3+ , and Zr 4+ ) which form strong coordination bonds with linkers, [27][28][29][30][31] incorporation of methyl groups near coordination sites, [32][33][34] and post-synthetic grafting of hydrophobic groups onto linkers, 35 among others. [36][37][38][39][40] With the ready availability and inexpensiveness of copper(II) salts, along with the predictable nature of formation of dicopper(II) paddlewheel secondary building units (SBUs), we have turned our attention toward investigating methods for enhancing the water stability of MOFs formed from combination of dicopper paddlewheel SBUs and carboxylate linkers.…”