Homogeneous Hysteresis

Surfactant-coated surfaces may also rearrange on contact with a liquid as shown by Israelachvili and co-workers [77]. This mechanism helps to explain hysteresis occurring on otherwise smooth and homogeneous surfaces. 

Existence of a large amount of mesopores usually results in the appearance of capillary condensation hysteresis loop. Type II AIs transform to type IV, and type III AIs transform to type V Type VI AIs are characteristic to low-temperature adsorption of some noble gases over energetically homogeneous surfaces. 

In the further scans, this first wave is not observed because in the aforementioned potential region, the electrode surface is no longer a pure platinum one but is a rearranged platinum hydroxide surface39. The results described in section 6.2 showed that the limiting-current plateau of the second oxidation wave (first scan) is controlled by transport of dithionite. This indicates that electron transfer from dithionite to PtOH and/or PtO is a much faster process than transport of dithionite towards the electrode. This is confirmed by the fact that in the further scans an identical limiting-current is obtained. The third oxidation wave in the first scan (second wave for the other scans) is attributed to the oxidation of sulphite described earlier. It is formed as a reaction product of the sodium dithionite oxidation and also of the homogeneous decomposition of sodium dithionite. Also in this case, a hysteresis effect is observed for the sulphite forward/back-ward sweep oxidation wave. 

The meaning of the contact angle a has been illustrated In fig. 1.1.1. Experimentally the procedure is not easy because, in addition to the requirements of surface purity and homogeneity, contact angle measurements may show hysteresis, but in a number of simple systems where such problems did not arise, the Identity of from [1.3.361 and from calorimetry has been ascertained ... 

The obtained vanadium dioxide films are characterized by a homogeneous finegrained nanostructure with grain size not exceeding 160 nm. The phase transition temperature was about 58 °C. All the samples are characterized by hysteresis of resistance and capacitance. The obtained results give evidence that there are an unoxidized vanadium and its lower oxides in the VO2 films as a separate scattered nanoinclusions. 

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