We show that ellipsometric porosimetry can be used for the measurement of the pore size distribution in thin porous films deposited on top of any smooth solid substrate. In this method, in situ ellipsometry is used to determine the amount of adsorptive, which is adsorbed/condensed in the film. Changes in refractive index and film thickness are used to calculate the quantity of adsorptive present in the film. Room temperature porosimetry based on adsorption of vapor of organic solvents has been developed. In this article, a method of calculation of pore size distribution and results of measurements on mesoporous and microporous xerogel films is discussed. Examination of the validity of the Gurvitsch rule for various organic adsorptives (toluene, heptane, and carbon tetrachloride) is carried out to assess the reliability of measurements of pore size distributions by ellipsometric porosimetry.

We have developed a sensitive, economical method that directly detects viruses by making use of the interaction between type 1 herpes simplex virus (HSV1) and specific antibodies covalently attached to the oscillating surface of a quartz crystal microbalance (QCM). The virions were detached from the surface by monotonously increasing the amplitude of oscillation of the QCM, while using the QCM to sensitively detect the acoustic noise produced when the interactions were broken. We term this process rupture event scanning (REVS). The method is quantitative over at least six orders of magnitude, and its sensitivity approaches detection of a single virus particle.

We present a new method of measuring bond rupture forces. It is based on the use of microparticles attached by many bonds or interactions of one type to an oscillating surface. We have used a quartz crystal microbalance and linearly increased the driving voltage resulting in bond rupture which can be detected both optically and acoustically. The rupture force spectra give sharp peaks which depend on the mass of the microparticle and the strength of the interactions attaching it to the surface. This method is applicable to weak interactions such as nonspecific adsorption through to strong chemical bonds. It has widespread potential applications in sizing, sorting, analyzing, and separations based on differences in rupture force.

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After fixing the DNA molecule in the form of a double helix on the surface of a thickness shear mode resonator (QCM), mechanical oscillations at increasing amplitude cause detorsion of the helix. The force necessary for detorsion can be determined from the voltage applied to the QCM at the rupture moment. The high sensitivity of this method is due to the fact that measurements are carried out in the frequency region around the QCM resonance, where any (even very weak) distortions of the consistent oscillating system cause noticeable distortions of the amplitude-frequency dependence, and these distortions are used to fix the rupture moment. The measured rupture forces were within 30-40 pN, and the sensitivity was 10(8) molecules. It was demonstrated that the proposed procedure allows one to determine the factors that affect the stability of the DNA double helix. This procedure can be the basis for the development of a new method of rapid DNA analysis. Experiments performed with model DNA showed that it is possible to reveal complementarity between two DNA samples.

Surfactant-templated organosilicate glass (OSG) based low-k films are deposited by using tetraethyl orthosilicate/methyltriethoxysilane (TEOS/MTEOS) mixture with different ratio and spin-on technology with the goal of understanding the effects of terminal methyl groups on chemical and structural properties. It is shown that despite of constant surfactant concentration these films have quite different properties when the changing of CH3/Si ratio. The most important changes are related to change of their hydrophilicity, change of mechanical properties, the pore size and to the shift of Si–CH3 peak position in Fourier transform infrared (FTIR) spectra. The films are becoming hydrophobic if they are deposited from sols with CH3/Si ratio higher than 0.2. The Young’s modulus gradually decreases with increasing the terminal methyl groups concentration in the films. The pore size increases with concentration of methyl groups and changes from cylindrical to ink-bottle shape. The nature of SiCH3 peak shift is explained by using molecular mechanics simulation. It is shown that the reason of this shift is change of dπ–pπ hybridization in Si–O–Si bonds, which is affected by presence of CH3 group.

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