Current Status and Future Prospects of Applying Bioinspired Superhydrophobic Materials for Conservation of Stone Artworks

Abstract

The development of innovative materials is one of the most important focus areas in heritage conservation research. Eligible materials can not only protect the physical and chemical integrity of artworks but also preserve their artistic and aesthetic features. Recently, as one of the hot research topics in materials science, biomimetic superhydrophobic materials have gradually attracted the attention of conservation scientists due to their unique properties. In fact, ultra-repellent materials are particularly suitable for hydrophobization treatments on outdoor artworks. Owing to their excellent hydrophobicity, superhydrophobic materials can effectively prevent the absorption and penetration of liquid water as well as the condensation of water vapor, thus greatly relieving water-induced decay phenomena. Moreover, in the presence of liquid water, the superhydrophobic surfaces equipped with a self-cleaning property can clean the dirt and dust deposited spontaneously, thereby restoring the artistic features simultaneously. In the present paper, besides the basic principles of wetting on solid surfaces, materials, and methods reported for preparing bioinspired ultra-repellent materials, the recently proposed materials for art conservation are also introduced and critically reviewed, along with a discussion on the droplet impact and durability of the artificial superhydrophobic surfaces. Lastly, the current status and the problems encountered in practical application are also pointed out, and the focus of future research is presented as well.

Partially perfluorinated derivatives as powerful tool for the restoration of blanching easel paintings

“…The characterization of DST was realized by assigning the signals in 1 H and 13 C NMR spectra (supporting information) also recording the 2D (gCOSY, gHSQC) spectra. Firstly, the presence of amino groups at the end of the polymeric chain was confirmed by the signals at 2.86 ppm in 1 H NMR spectrum and near 38.4 ppm in 13 C NMR (CH2NH2).…”

“…The characterization of DST was realized by assigning the signals in 1 H and 13 C NMR spectra (supporting information) also recording the 2D (gCOSY, gHSQC) spectra. Firstly, the presence of amino groups at the end of the polymeric chain was confirmed by the signals at 2.86 ppm in 1 H NMR spectrum and near 38.4 ppm in 13 C NMR (CH2NH2). The absence of a singlet signal in the 3.60-3.80 ppm in the H NMR spectroscopy is not only a reliable tool for molecule characterization, but also a valid method to elucidate polymer structures and estimate the average molecular weight (Mn) [25] [26].…”

“…This molecular structure confers the compound good hydrophobicity, high thermal and chemical stability, all properties due to the high bond energy of C-F bond and highly electro-negative fluorine atoms [11] [12]. As a result, polymer containing perfluorinated moieties have been widely used in heritage conservation field, such as in stone material protection, wooden artifact protection [13][14] [15][16] [17]. DC6G900, synthesized from isobutyl ester of perfluoropolyetheric monocarboxylic acid and hexamethylenediamine (Fig.…”

“…NMR and a signal at 52 ppm in the13 C NMR, both attributable to the -OCH3 in the terminal ester, further determined the presence of two terminal amino groups in DST. The presence of different monomeric units was confirmed by the characteristic signals (see supporting information) https://doi.org/10.26434/chemrxiv-2023-w50m1 ORCID: https://orcid.org/0000-0003-0371-6306 Content not peer-reviewed by ChemRxiv.…”

Preparation of Fluorine-Free Superhydrophobic Paper with Dual-Response of Temperature and pH

“…There are many preparation methods for superhydrophobic paper, mainly including the dipping method, the chemical etching method, the electrophoretic deposition method, the electrospinning method, the chemical vapor deposition method, the plasma etching method, and the spraying method, etc. [25]. However, in these methods, some of the reagents used in the preparation process will be harmful to the environment, and some preparation processes and required equipment are complicated, so it is very important to choose the appropriate reagents and preparation methods.…”