DETERMINATION OF BASIC CHARACTERISTICS OF PROTECTIVE LAYERS BASED ON POLYMERIC NANOFIBERS
This work focuses on a basic research in developing new class of protective layers for building materials based on polymeric nanofibers. Nonwoven nanotextiles are fibers with diameter spanned from tens to hundreds of nanometers. Thin films consisting of suitable polymer-based nanofibers were prepared using NANOSPIDER equipment. Applied technology is unable to fully guarantee quality (homogeneity, thickness, etc.) of the protective coating. Traditionally used technologies –such as painting or spraying – are not too effective and the separation of protective coating or loosing of protective properties is frequently observed.
Nucleation on Polymer Nanofibers and their Controllable Conversion to Protective Layers: Preliminary Theoretical Study
Nanofibers are very promising new type of material with a broad range of possible applications. The new NANOSPIDER technology opens a possibility to produce nanofabrics in an amount large enough for them to start being interesting as a construction material. There are many so-called passive applications of nanotextiles (including different types of filters and protective layers), and active applications, when the active chemical agent is incorporated in their structure. In the present paper, however, the new possible application of nanofabrics is proposed: as a base material on which technically interesting nanoclusters are heterogeneously nucleated. The basic thermodynamics of heterogeneous nucleation on nanofibers is considered. The extreme curvature of nanofibers manifests itself in an energetic barrier of nucleation, which is quite different from a case of nucleation on a flat surface. The expression for Gibbs energy of cluster formation is derived, taking into account the elastic strain resulting from a volume (or shape) changes during nucleation.
Analysis of Suitability of Mortar Used for Reconstruction
Assessment of suitability of mortar intended for reconstruction based on their characteristics, namely basic, hygric and mechanical parameters, chemical analysis and frost resistance, is presented in this paper. Properties of the load bearing structure as well as natural factors were also taken into account in assessing the suitability of the used mortars. Comparative measurements with original historic plaster are done as well. On the basis of the experiments performed, it can be concluded that not only mortar properties but also environment conditions and technology of application as well as load bearing structure characteristics have a great importance to the service life of the repaired parts of historical buildings.