Water-Resistance of Nanofiber Textiles

This work deals with the determination of basic waterproofing properties of nanofiber textiles with basis weights of up to 30 g/m2. Samples used in this experiment were made from nanofiber textiles based on two polymers – PVDF and PUR. Each polymer was prepared in three basis weights. All samples were not treated prior to testing. One of the key properties was the contact angle of water and the resistance to penetration of liquid water. Water-resistance of nanofiber textiles was tested according to the harmonized European standard EN 13859-1., Underlays for discontinuous roofing in pitched roof constructions are tested according to this standard. In the position of underlays there has to be some layer with low diffusion resistance of water vapor and relatively high waterproofing. We suppose such properties of nanofiber textiles. Testing of the two groups of material basis shows correlation between the contact angle and water-resistance of the nanofiber textile.

The Efficiency of PVA Based Nanofiber Textile PVA Doped Silver Particles against Mold

Mold and algae are primitive organisms that cause biological degradation of many type of construction materials. Subsequent remediation of damaged structures is very demanding and it is therefore necessary to take into consideration the high preventive protection against these microorganisms. In practice, as the prevention it is often use chemical products as a classical biocidal compounds. One of the modern methods of protection investigate the use of nanotechnology with biocidal ingredients, which is the main topic of this article. Silver ions and silver nanoparticles were selected as a biocide for the experiment. Research revealed that the silver in the form of nanoparticles and ions have biocidal effect against fungi and algae and it is conform to use theoretically possible them as a preventive protection against mold and algae.

The Dependence of Concentration Copper Ions in Nanofibers (PVA) on Composition of Original Basic Electrospin Solution and on Kind of Stabilization

The nanofiber textile was made by electrospinning on device Nanospider LB 500 (Elmarco, CR). The original basic polymer solution contains polyvinyl alcohol and additional supplement: a glyoxal and phosphoric acid for thermal stabilization and copper sulphate as a biotic agent. The concentration of copper sulphate pentahydrate (CuSO4·5H2O) in original basic polymer solution was 0.5 and 1% and it follows that the theoretical concentration of copper ions in nanofibers was 0.95 and 1.89%. Subsequently the nanofibers had stabilized by thermal heat (140 °C, 10 min), and by chemical cross linking methods with using of soaking in solution with glutaraldehyde, methanol. The stabilized nanofibers were characterized by scanning electron microscope (SEM) and atomic absorption spectrum (AAS). The results showed that the thermal stabilization did not change nanostructures too much, but subsequent soaking showed, that their structure has changed after 24 hour leaching, the crosslinked points has not sharp line. This measurement leads to conclusion, that the stabilization by heat is not fully absolute. Chemical stabilization nanofibers by glutaraldehyde changed the nanoproperties only in range a few percent and the solubility in water was absolutely completed. The stabilization by methanol has destroyed nanostructures of the fabrics, and the nanofiber textile looks like thin layer or thick membrane. The nanostructures didn't change their character nor after water soaking. The content of copper in nanofiber had measured by (AAS) and thus proved that the copper concentration in nanofiber is independent on original concentration in solution. The next results from this measurement confirm the assumption that the concentrations of copper are dependent on kind stabilization. The next results from this measurement confirm the assumption that the concentrations of copper are dependent on kind stabilization. The stabilization by soaking in stabilization solution leads to decrease of concentration of copper in nanofiber. The thermal stabilization didn't change final content of copper in nanofiber, the stabilization by glutaraldehyde changed the concentration, it was lower by 2 mg/g and the stabilization by methanol made nanofiber with one quarter original value of copper.