Global excitation and local probing of ferroelectric domains

In this work, the macroscopic polarization of a ferroelectric capacitor is correlated with the local domain morphology. To this end, a ferroelectric capacitor of the random copolymer poly(vinylidenefluoride-trifluoroethylene) [P(VDF-TrFE)] is poled to a set polarization state in a Sawyer-Tower setup. After chemically removing the top electrode,...

Ferroelectricity and piezoelectricity in soft biological tissue: Porcine aortic walls revisited

Recently reported piezoresponse force microscopy (PFM) measurements have proposed that porcine aortic walls are ferroelectric. This finding may have great implications for understanding biophysical properties of cardiovascular diseases such as arteriosclerosis. However, the complex anatomical structure of the aortic wall with different...

Microstructure development of a drying tile mortar containing methylhydroxy-ethylcellulose (MHEC)

Cement based mortars are widely used as adhesive for tiles in building and construction. They have a limited timespan during which a tile can be placed effectively in order to develop sufficient bond strength. This timespan, usually called ’open time’, is controlled, amongst others, by adding water soluble polymers such as methyl cellulose or...

Simulation of the self-healing of dolomitic lime mortar

A test procedure was set up to reproduce laboratory self-healing on lime-based (both pure calcium and magnesium-calcium) mortar specimens. After a few months of testing, during which time the specimens were submitted to wet-dry cycles, thin sections of the specimens were prepared and observed using a polarization and fluorescence microscope (PFM...

Low tensile strength in older concrete structures with alkali-silica reaction

During an extensive investigation of some 25 concrete bridges and other structures suffer-ing from alkali-silica reaction it has been found that the uniaxial tensile strength of the concrete was extremely low in relation to both the compressive strength and the splitting tensile strength. It is known that concrete with damage due to ASR has...

Investigation of the conservation-treatment methods of the Dutch National Monument: The role of microscopy

The Dutch National Monument in Amsterdam, a World War-II memorial structure, was built with an outer face consisting of slabs of travertine. In 1995, the masonry structure forming the core of the monument showed severe deterioration. In order to determine the actual cause of deterioration and to advise on the most suitable method of restoration,...

Composition of mortar as a function of distance to the brick-mortar interface: A study on the formation of cured mortar structure in masonry using NMR, PFM and XRD

The formation of cured mortar structure in masonry was studied using multiple experimental techniques. Starting with fresh mortar, nuclear magnetic resonance (NMR) was used to measure the water extraction during brick laying. After curing, the composition of cured mortar was investigated with polarizing and fluorescent microscopy (PFM) and X-Ray...