Intercalation Study of Low‐Molecular‐Weight Hyperbranched Polyethyleneimine into Graphite Oxide

Abstract

We report for the first time the intercalation of low-molecular-weight hyperbranched polyethyleneimine (PEI) into graphite oxide (GO) for the facile, bulk synthesis of novel graphene-based hybrid (GO-PEI) materials exhibiting tailored interlayer galleries. The size of the intercalant as well as the loading in GO were systematically investigated to determine their contribution to the basal spacing of the resulting materials. Powder X-ray diffraction measurements demonstrated the generation of constrained hybrid systems along the c axis that exhibit considerably increased interlayer distances compared with the starting, pristine GO. The results of X-ray photoelectron and FTIR studies are consistent with a "grafting-to" process of the intercalated PEI with the oxygen functional groups present along the GO framework. Furthermore, it was found that a great number of the nitrogen-containing groups in PEI still remain available within the newly formed, confined micro-environment of intercalated GO galleries. The increased surface area of the GO-PEI hybrids in conjunction with the remaining available active groups of intercalated PEI render the synthesised hybrids very attractive candidates as nanostructured adsorbents.

Copper(II) complex intercalated graphene oxide nanocomposites as versatile, reusable catalysts for click reaction

“…In addition, the notable diffraction peaks at 37.90° and 39.50° correspond to (111) plane of monoclinic CuO (JCPDS 80‐1917) and at 42.40°, 49.90° and 42.60°, 48.00° were indexed to (111) and (200) planes of metallic Cu particles (JCPDS 04‐0836) exist in the GO‐C1 and GO‐C2 nanocomposites, respectively. [ 39–41 ] The as‐prepared composites were also characterized by FT‐IR, XPS, Raman, and UV spectroscopic techniques. FT‐IR spectra of GO‐C1 and GO‐C2 material (Figure 1b) show the characteristic peaks at 3,614, 3,414 cm −1 and 3,654, 3,447 cm −1 correspond to NH str and OH str vibrations, respectively.…”

Polyethylenimine Expanded Graphite Oxide Enables High Sulfur Loading and Long‐Term Stability of Lithium–Sulfur Batteries

“…Intercalation of PEI into GO layers was driven by both chemical reactions and electrostatic interactions between the amine groups on PEI and the oxidation‐generated hydroxyl, carbonyl, and epoxy functionalities on GO . A low molecular weight hyperbranched PEI (1800 Da) was used to facilitate the ease of diffusion of PEI into the GO layers.…”

“…Upon sulfur loading, I D / I G further increases to 1.17 in S/PEI‐GO and 0.90 in S/GO, indicating the CC sp 2 bond is further interrupted by sulfur. [15b] Furthermore, the characteristic sulfur peaks in the range of 100–600 cm −1 were detected on both sulfur/host samples. Compared to the relatively strong sulfur peaks in S/GO, they are much weaker in S/PEI‐GO, which further confirms a better sulfur distribution in PEI‐GO …”

Mixed Matrix PVDF/Graphene and Composite‐Skin PVDF/Graphene Oxide Membranes Applied in Membrane Distillation

“…Aqueous dispersions of GO were produced starting from graphite powder using the well‐established and widely recognized modified Staudenmaier's method . In a typical procedure, 10 g of powdered graphite (purum, powder ≤0.2 mm) were added to a mixture of concentrated sulfuric acid (400 mL, 95–97 wt%) and nitric acid (200 mL, 65 wt%), while cooling it in an ice‐water bath.…”