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Paraloid B72, composed of an ethyl methacrylate (70%) and methyl acrylate (30%) copolymer, is widely used in the field of cultural relics protection due to its transparency, durability, and nonyellowing. However, B72 is hydrophilic and the water resistance should be enhanced. Herein, as a further study of the pioneer research by Ntelia et al. [1], transparent superhydrophobic coating was prepared and the durability as well as the protection against moisture will be studied. B72 was mixed with the hydrophobic nanoparticles of SiO 2 in xylene and a transparent and superhydrophobic coating was then obtained by spraying onto the substrate of fabric, paper and wood. The fraction of SiO 2 in the mixture was optimized to be 2 wt% by taking hydrophobicity, air permeability, transparency, and ultraviolet transmittance into consideration. The optimal coating presented a continuous porous network surface structure with the maximum contact angle of 165° and the minimum sliding angle of 6°. Average transmittance in visible and ultraviolet light range for the composite coating on glass was 72.57% and 19.46%, versus 82.81% and 32.26% for B72, respectively. BS2 coating permeability for different substrates are less than 10%. Contact angle remained above 150° after 4 h of contact with liquids with a pH of 1–13. Water contact angle on the simulated paper relics after exposure to a hot humid (60 °C, 85 – 90 RH%) atmosphere for 5 days remained above 150°. In addition, BS2 coating showed good UV resistance after 10 days of UV light irradiation. All these data demonstrated that such a coating may find potential application in the relic protection due to its superhydrophobicity, breathability, transparency, ultraviolet protection, and durability. [Display omitted] [ABSTRACT FROM AUTHOR]

Paper acidification causes paper relics to undergo embrittlement and decay, to form dregs, and even to break upon a single touch; therefore, reinforcement and deacidification treatments are essential steps for paper conservation and to retard the deterioration and prolong the life of objects. Polymeric adhesives play an essential role in reinforcement and deacidification treatments, although it is not well studied. In this work, the effect of polymeric adhesives on the conservation process and their protective effects on acidified paper relics were studied. Firstly, three polymeric adhesives, including wheat starch paste, polyvinyl butyral (PVB), and polyvinyl alcohol (PVA), were selected as research objects. Subsequently, their effects on four popular conservation methods were further discussed, including traditional mounting, hot-melt with silk net, alcohol-soluble cotton mesh, and water-soluble cotton mesh. Additionally, as an example, the reversibility and long-term durability of water-soluble adhesive PVA-217 were assessed. Using a computer measured and controlled folding endurance tester, pendulum tensile strength tester, tear tester, burst tester, FT-IR, video optical contact angle tester, and other instruments, the conservation application of water-soluble adhesives in paper relics was evaluated. This study provides a scientific basis and experimental data for the application of polymeric adhesives in the conservation of paper relics. [ABSTRACT FROM AUTHOR]

The incorporation of photocatalytic nanomaterials into polymer coatings is used to protect stone relics from weathering. However, the photocatalytic nanomaterials might generate excess free radicals to degrade the polymer matrix. In this work, a certain amount of TiO2 nanoparticles were dispersed into Paraloid B72 and applied onto sandstone relics to explore the adverse effects of TiO2 nanoparticles on Paraloid B72 under ultraviolet (UV) irradiation. To fulfill this goal, the effects of TiO2 on pore formation and the structure of Paraloid B72 was studied by scanning electron microscopy (SEM). Moreover, the surface chemical composition, pore structure, surface roughness and surface wettability were explored via Fourier transform infrared (FTIR) spectroscopy, SEM, optical profilometer and water contact angle measurement under UV irradiation. Results showed that the incorporation of TiO2 nanoparticles prohibited the generation of pores in Paraloid B72 and there were no pores formed when the content of TiO2 exceeded 0.8 wt%. The water contact angle of origin Paraloid B72 and TiO2/Paraloid B72 decreased with the prolonging UV irradiation. Moreover, TiO2 nanoparticles were extracted from the matrix and the pores cannot be detected with the prolonging UV irradiation time under a higher content of TiO2. These research findings might promote the understanding of using photocatalytic nanomaterials in developing stone relics' protective coating. [ABSTRACT FROM AUTHOR]

• The high hydrophobicity of preservation materials can cause damage to tabia. • Salt crystallization, moisture and thermal expansion facilitate damage process. • High hydrophobic materials should be avoided for tabia's conservation. Silicone has commonly been used to preserve and protect tabia relics. However, it was recently observed in numerous circumstances, that the addition of silicone facilitates failures on the consolidated parts, e.g., warping and detachment, thereby accelerating the destruction of the tabia relics. Thus, the goal of this study is to perform preliminary research work on the long-term effectiveness of tabia preservation materials. Two silicone tabia preservation materials with different hydrophobicity were prepared. Tetraethoxysilane (TEOS) supplemented with additives hydroxyl-terminated polydimethylsiloxane (PDMS-OH) and cetyltrimethylammonium bromide (CTAB) with a static water contact angle of 110°, served as the low hydrophobicity preservation material; while hexadecyltrimethoxysilane (HDTMS) with a static water contact angle of 110° provided the high hydrophobicity preservation material. Both the two preservation materials were used on the Zhenyuan Tabia Fort in Ningbo City, Zhejiang Province, China. Multi-factor deterioration experiments, including capillary water absorption with Na 2 SO 4 solution, salt crystallization, freeze-thaw cycle, and wet-dry cycle were performed to assess the causes of the damage induced by the preservation materials. The results indicate that the use of the high hydrophobicity of preservation material facilitates damage to the tabia relics. [ABSTRACT FROM AUTHOR]

Paper-based relics, which are an important part of cultural heritage worldwide, are at risk of imminent damage from various environmental sources. To protect them, the atmospheric pressure plasma polymerization of hexamethyldisiloxane (HMDSO) precursor has been explored on paper-based relics in situ. The macro and micro images taken during this process suggest that the in situ plasma treatment does not change the macro morphology and the micro structure of the treated paper-based relic samples. On the other hand, plasma treatment causes the polymerization of the HMDSO which then produces nanoparticles deposited onto the paper-based relics. These nanoparticles provide good waterproof properties with large static water contact angles and smaller rolling angles, which protect the paper-based relics from water penetration. Moreover, since the nanoparticles are deposited onto the fibers, waterproof fastness is ensured. Also, the examined mechanical properties of the treated and untreated paper-based relics indicate that the atmospheric pressure plasma treatment does not affect the strength of the paper very much. The results in this study show that atmospheric pressure plasma treatment with the use of HMDSO precursor is a good method to preserve paper-based relics. [ABSTRACT FROM AUTHOR]