Efficient Adsorption of Dyes Using Polyethyleneimine-Modified NH₂-MIL-101(Al) and its Sustainable Application as a Flame Retardant for an Epoxy Resin

Abstract

Metal–organic frameworks (MOFs) exhibit highly designable properties and have been used in wide applications. To further improve their performance, the modification of MOFs is an effective method. However, the modification process is usually complicated. Besides, the sustainable use of MOFs is difficult to achieve due to the complicated recycling treatment. Herein, we designed a polyethyleneimine (PEI)-modified NH 2 -MIL-101(Al) composite (PEI@NH 2 -MIL-101(Al)). This composite showed excellent dye removal performance of methyl orange (MO, 89.4%) and Direct Red 80 (DR80, 99.8%). Remarkably, the dye removal application of PEI@NH 2 -MIL-101(Al) also acted as a modification process toward flame retardant application. Thus, the dye-adsorbed PEI@NH 2 -MIL-101(Al) composite (MO-PEI@NH 2 -MIL-101(Al) and DR80-PEI@NH 2 -MIL-101(Al)) was sustainably used as an effective flame retardant for an epoxy resin (EP) at low additions (4.0 wt %). The limiting oxygen values of EP/MO-PEI@NH 2 -MIL-101(Al) and EP/DR80-PEI@NH 2 -MIL-101(Al) increased to 26.5 and 26.7%, respectively. The heat release and the smoke production of dyes-PEI@NH 2 -MIL-101(Al)/EP were greatly reduced compared with those of EP. This strategy provides a simple and effective modification method for MOFs. Meanwhile, the modified MOF composite can achieve sustainable application, giving full play to the advantages of MOFs.

The design of a metal–organic framework with flame-retardant performance and bionic hydrophobic surface inspired by the lotus leaf

“…The temperatures at 5% and 50% mass loss and the maximum mass loss rate temperature are defined as T 5% , T 50% and T max , 12 respectively. The value of T 5% can reflect the thermal stability at the initial heating stage 17 and this value for the pure PS is 343 1C under the N 2 atmosphere. The addition of S-Fe-MOF significantly increases the corresponding value of PS/S-Fe-3.0 to 430 1C.…”

Composites Filled with Metal Organic Frameworks and Their Derivatives: Recent Developments in Flame Retardants

“…On the other hand, due to the presence of -NH 2 , NH 3 is released during the combustion of EP, which dilutes the combustible gas and acts as a flame retardant in the gas phase. Wang et al [ 88 ] modified NH 2 -MIL-101(Al) with polyethyleneimine (PEI) and used adsorbed dye as a further modification step to achieve sustainable application of MOF materials. Meanwhile, the synergistic effect of adsorbed dyes, MOF, and PEI enhanced the flame-retardant properties of EP.…”

A Study on a Magnesium-Based Layered Composite Used as a Flame Retardant for Phenolic Epoxy Resins

“…(3) Experimental characterization means X-ray diffraction (XDR) was mainly adopted to characterize the crystal structure of the samples [9]. Sample pretreatment: the dried sample was ground into the powder with a mortar, and then the tablet was pressed into the mold.…”