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The conservation of weathered historic sandstone with apatite was studied. Based on the growth mechanism of bone, calcium and phosphorus were introduced into weathered sandstone and then mineralized at room temperature. The conservation efficiency was investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), and compressive strength, capillary water uptake, water vapor permeability and weather resistance tests. The SEM, EDX, TEM, SAED and XRD results showed that the produced hydroxyapatite could reunite the weathered stone blocks and provide sufficient reinforcement to hold them together. The results of the various tests indicated that the compressive strength and weather resistance of the treated samples was improved significantly. In addition, because of the porous nature of apatite, the water vapor permeability of the treated stone was not affected and its breathability was maintained.

Poly(ionic liquid) surfaces with tunable wettability were successfully prepared on micro/nanoscale CuO/Cu composite substrates by a surface-initiated nitroxide-mediated radical polymerization technique. Various characterization techniques including X-ray photoelectron spectroscopy, cold field emission scanning electron microscopy, and static water contact angle measurement were used to characterize the surfaces for each surface modification step. Kinetic studies revealed that the polymer chain growth from the surface was a controlled/''living'' polymerization process. The surface with tunable wettability, reversible switching between hydrophilicity and hydrophobicity can be easily achieved by sequential counteranion exchange.

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