Scenarios of Engineered Membranes in Cultural Heritage: How Do Membranes Act on Microclimates and Microenvironments?

Conservation is one of the critical issues for cultural heritage assets. A lot of materials are daily proposed to clean, repair, and restore monuments, but best practices are still in high demand to prevent artwork deterioration. Membrane science provides practical and sustainable solutions, including buffer environmental zones, to preserve cultural assets from physical, chemical, and biological agents. Protection can be obtained in an outdoor context in order to counteract the effects of climatic changes, variations of temperature, violent storms, bright lighting, and the wear of time. Removable and aesthetic structural membranes are hence proposed to give protection and a comfortable environment without affecting the meaning of the historical monuments. Similarly, indoor membrane-based solutions can be applied to versatile situations, yielding surroundings targeted for specific classes of materials. Required ambiences may be identified, and regulation of levels of humidity, gases, and vapors, as well as fluctuations of heat can be established. Air cleaning can be obtained through the elimination of nanoparticles and dust, while bacteria, fungi, molds, and viruses can be in situ neutralized. Water infiltration and salt crystallization can be hindered. The membrane concept relies on the capability to transfer mass, energy, and charge through an interface under specific working conditions and can be easily adapted to the space needing protection. Due to their ability to perceive changes in the local environment, responsive membranes can be further aimed at realizing intelligent devices if integrated with AIoT monitoring tools. Different contexts are herein analyzed and discussed, highlighting the great potential of using advanced materials-membranes to keep balanced and clean ambiences for safe and wholesome cultural assets. Case studies are reported on how new sustainable practices can make preventive action efficient, quick, and durable, resulting in much more effective and resourceful conservation. Current status, potential membrane applications, and future perspectives are herein described in order to provide answers to some of the most important questions in works of art conservation, which are still unsolved or partially solved.