p-Phosphonic acid calix[8]arene assisted exfoliation and stabilization of 2D materials in water

Abstract

Exfoliated 2D materials including graphene, BN, MoS(2) and WS(2) are accessible in water over a wide range of pH for a synergistic process involving sonication in the presence of p-phosphonic acid calix[8]arene.

p‐Phosphonated Calix[n]arene Stabilizes Superparamagnetic Nanoparticles for Nitrate and Phosphate Uptake

“…[36] Thus, the lowest PCalix[n] concentrationt ested was presumed to be too low to oxidise Unlike the smaller phosphonatedc alixarenes, the largest macrocycle studied, PCalix [8], did not appear to exert shape control over crystal growth at the concentrationss tudied. This result was unexpected given the ability of PCalix [8]t op referential order relative to the orientation of the hexagonal motif of graphene [12] and direct the growth of ultra-small faceted nanoparticles of platinum. [13a] The conformational flexibility of the large ring presumablyp romotes its interactions with the flat surfaces of carbonm aterials.…”

“…[8] p-Phosphonated calix[n]arenes (n = 4, 5, 6, and 8, PCalix[n]; Figure 1, are non-toxic and water soluble, depending on pH. [9] They are versatile, being used as surfactants, [10] agentsf or drug delivery, [11] 2D material exfoliation [12] and nanoparticle stabilisation. [13] In general,t he high surface area of nanoparticles or nanosheets is advantageous in creating al arge surfacea rea for small amounts of material.…”

Amphiphilic graphene oxide stabilisation of hexagonal BN and MoS2 sheets

“…It is also difficult to produce stabilised inorganic lamellar materials, including BN and MoS 2 , in aqueous media in the absence of additional surfactants due to their hydrophobic property. 18,19 Indeed access to water-processable quasi-graphene forms such as graphene oxide and reduced graphene oxide has dramatically advanced the potential of graphene-based materials into much broader areas. 20,21 Hence, there is significant scope for developing novel and versatile solution-based protocols to prepare waterdispersible heterolaminar van der Waals materials.…”

Ultra-thin films for plasmonics: a technology overview

“…For example, boron nitride, molybdenum bisulfide, and tungsten sulfide [148] are possible candidates to achieve controllable, wafer-scale monoatomic thicknesses. Nevertheless, these types of two-dimensional materials have only recently appeared in the focus of investigation, and their comprehensive optical characterization is yet to be done.…”

“…Although there are several ways of obtaining graphene [148], the most used two are through exfoliation from graphite [149,150] and using CVD techniques on Cu [151] or Ni [152] substrates.…”