Growth of Nanostructured Antibacterial Zeolitic Imidazolate Framework Coatings on Porous Surfaces

Abstract

Morphological tailoring of crystalline nanomaterials such as zeolitic imidazolate frameworks (ZIFs) is essential for various applications, including oil-water separations, molecular sieving, and antibacterial applications. However, precise control of the morphology of these crystals is challenging. Herein, the morphological evolution map of ZIF-L to ZIF-8 nanocrystals on porous polymer supports was constructed in terms of ethanol content and processing temperature variation. Subsequently, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) analyses demonstrated that an increase in the temperature in low ethanol content led to the formation of ZIF-L nanocrystals with decreased lateral size and increased crystal thickness. Comparatively, increased ethanol content typically increases crystal thickness with a greater degree of crystal intergrowth. However, an increase in both parameters exhibited a preferential formation of its three-dimensional (3D) structural analog, ZIF-8, and consequently resulted in a ZIF-L/ZIF-8 mixed phase at midrange temperatures (50–60 °C) and ethanol content (10 v/v%). The mixed phase demonstrated the stacking of ZIF nanosheets, with the morphology change significantly impacting the properties of the ZIF nanocrystals. As one example, the antibacterial performance of the as-prepared materials of different morphologies was analyzed to investigate the morphological impact on antibacterial efficiency. It was found that crystals with reduced crystal size and increased surface area resulted in improved antibacterial performance. Meanwhile, the nanostructured ZIF coating’s hydrophilicity and hydrostability were also enhanced with increased ethanol content and elevated temperatures. Overall, we reported a very useful method to conveniently control the morphology of ZIF nanocrystals for improved applications.

Synthesis of Metal–Organic Framework-Based ZIF-8@ZIF-67 Nanocomposites for Antibiotic Decomposition and Antibacterial Activities

“…On the other hand, Figure B exhibits that the pristine ZIF-8 enhances E. coli growth inhibition zone and bacterial viability on agar plates, while also enhancing antibacterial activity and decreasing bacterial viability, suggesting potential applications and future research directions . Additionally, Figure C measures the growth inhibition zone of E.…”

“…On the other hand, Figure 10 B exhibits that the pristine ZIF-8 enhances E. coli growth inhibition zone and bacterial viability on agar plates, while also enhancing antibacterial activity and decreasing bacterial viability, suggesting potential applications and future research directions. 64 Additionally, Figure 10 C measures the growth inhibition zone of E. coli when pristine ZIF-67 is added to an agar plate, indicating its antibacterial activity and density, and its potential as a novel agent compared with ZIF-8. 65 In contrast, Figure 10 D shows E. coli colonies with the 6ZIF-67/ZIF-8 nanocomposite, showing significant improvement in activity.…”

Zeolitic imidazolate framework-8 encapsulated with Mo-based polyoxometalates as surfaces with antibacterial activity against Escherichia coli

“…6 The development of a highly porous nanomaterial that has topological roughness can be a promising candidate for the creation of antibacterial surfaces with combined release-based and mechano-bactericidal effects. 7 In 1995, a breakthrough emerged in the eld of nanoporous materials with the introduction of metal-organic frameworks (MOFs). 8 MOFs are primarily composed of metal nodes or clusters attached by coordination bonds to organic linkers, constituting a highly customizable and adjustable porous structure and an exceptionally high surface area ranging from 1000 to 10 000 m 2 g −1 .…”

“… 6 The development of a highly porous nanomaterial that has topological roughness can be a promising candidate for the creation of antibacterial surfaces with combined release-based and mechano-bactericidal effects. 7 …”