A basic and affordable experimental apparatus is described that measures the static contact angle of a liquid drop in contact with a solid. The image of the drop is made with a simple digital camera by taking a picture that is magnified by an optical lens. The profile of the drop is then processed with ImageJ free software. The ImageJ contact angle plugin detects the edge of the drop and fits its profile to a circle or an ellipse. The tangent to the triple line contact is calculated and drawn by the ImageJ software, thus, returning the value of the contact angle with acute precision on the measurement.

A simple and straightforward method of depositing nanostructured thin films, based on LiCl-doped TiO 2 , on glass and LiNbO 3 sensor substrates is demonstrated. A spin-coating technique is employed to transfer a polymer-assisted precursor solution onto substrate surfaces, followed by annealing at 520°C to remove organic components and drive nanostructure formation. The sensor material obtained consists of coin-shaped nanoparticles several hundred nanometers in diameter and less than 50 nm thick. The average thickness of the film was estimated by atomic force microscopy (AFM) to be 140 nm. Humidity sensing properties of the nanostructured material and sensor response times were studied using conductometric and surface acoustic wave (SAW) sensor techniques, revealing reversible signals with good reproducibility and fast response times of about 0.75 s. The applicability of this nanostructured film for construction of rapid humidity sensors was demonstrated. Compared with known complex and expensive methods of synthesizing sophisticated nanostructures for sensor applications, such as physical vapor deposition (PVD) and chemical vapor deposition (CVD), this work presents a relatively simple and inexpensive technique to produce SAW humidity sensor devices with competitive performance characteristics.

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A series of copper(ii) complexes with earlier reported ligands N,N'-bis(2-hydroxyiminopropionyl)-1,2-diaminoethane (H(2)pen) and 1,3-diaminopropane (H(2)pap) and novel open chain oxime and amide ligands, N,N'-bis(2-hydroxyiminopropionyl)-1,5-diaminopentane (H(2)papt), 1,6-diaminohexane (H(2)pah) and 1,7-diaminoheptane (H(2)pahp), were prepared and characterized by a variety of spectroscopic methods and X-ray structure analysis. Although a pH-potentiometric study revealed only monomeric species in solution, formation of both binuclear dimeric and 1D-polymeric topologies was found in solid state. In all complexes ligands provide bis-bidentate coordination to Cu(2+) ions via the nitrogen atoms of the oxime groups and the oxygen atoms of the amide groups to form CuN(2)O(2) planar fragments. Compound [Cu(Hpap)(ClO(4))(H(2)O)](x) was isolated in both dimeric (x = 2) and polymeric (x = n) state, representing an example of supramolecular isomerism. All the complexes are additionally stabilized by short intramolecular hydrogen bonds =N-O-H...O-N= between cis-arranged oximato-groups. Stabilization is more effective in the case of dimeric complexes compared to 1D-polymeric chain, which appears to be the reason of preferable dimerization versus polymerization in the studied set of compounds. The effect of polymethylene linker length on the conformation of the dimers is described.