Quantitative Determination of the Hydrophobicity of Nanoparticles

Abstract

The hydrophobicity of nanoparticles (NPs) is one of the most important physicochemical properties that determines their agglomeration state under various environmental conditions. When studying nano−bio interactions, it is found that the hydrophobicity of NPs plays a predominant role in mediating the biological response and toxicity of the NPs. Although many methods have been developed to qualitatively or quantitatively determine hydrophobicity, there is not yet a scientific consensus on the standard of characterizing the hydrophobicity of NPs. We have developed a novel optical method, called the maximum particle dispersion (MPD), for quantitatively characterizing the hydrophobicity of NPs. The principle of measurement of the MPD method lies in the control of the aggregation state of the NPs via manipulating the van der Waals interactions between NPs across a dispersion liquid. We have scrutinized the mechanism of the MPD method using a combination of dynamic light scattering and atomic force microscopy and further verified the MPD method using a completely independent dye adsorption method. The MPD method demonstrated great promise to be developed into an easy-to-use and cost-effective method for quantitatively characterizing the hydrophobicity of NPs.

Applicability of OECD TG 201, 202, 203 for the aquatic toxicity testing and assessment of 2D Graphene material nanoforms to meet regulatory needs

“…hydrophobicity, OECD WNT project 1.7). For example, a maximum particle dispersion (MPD) methodology (and dye absorption method, Li et al, 2022) has been successfully used to measure the hydrophobicity of a graphene nanoplatelet (30.9 mJ/m 2 and 0.8 according to respective methods). Other methods used include a water contact angle method with values of and 79 for a single and multiple layer graphene (Bahl et al, 2020).…”

Lanthanum-based nanomaterials suppress bacterial wilt in tomato: importance of particle morphology and dissolution profiles

“…The relative hydrophobicity of La based NMs was analyzed according to Li et al (2022). 32 The full details are described in the ESI† (Experiment S1). To assess the ion release ability of different La based NMs, 100 mg L −1 La based NMs suspensions were prepared and shaken at 200 rpm min −1 .…”

Express method for particle size analysis in solid, liquid, and amorphous materials using 3D calibration curve and 2D-DLS dynamic light scattering

“…There are a large number of instrumental methods for determining the size of nanoparticles in solutions 1,2 . Laserbased analytical methods 3 , such as static and dynamic laser light scattering 4,5 , are widely used, both separately and in combinations with other physical and chemical techniques. These methods, however, are subject to a number of restrictions 6 .…”