Enthalpies of wetting of two active carbons and one brown coal coke by several pure liquids (mainly homologous series) were
measured at 298.15 K with two quasi-isothermal microcalorimeters. Different measuring cells with cavities of about 0.5 and
15 cm3 were used. The advantage of the larger measuring cell with three independent 15 cm3 cavities is the higher mass of active carbon, leading to a high reproducibility with standard deviations below 1% and a reduced
measuring time. Experiments were carried out with n-alkanes, l-alkanols, cycloalkanes and isomers thereof, i.e. 2-propanol,
methylcyclohexane, 2,2,4-trimethylpentane (isooctane and 2-ethyl-1-hexanol, and water. Like the polarity, the size and the
three-dimensional expansion of the molecules, the energetic and geometric heterogeneity of the adsorbent influences the enthalpy
The state of water and several transitions were examined in the systemsn-decanephosphonic acid (DPA)—water and the sodium salts of DPA—water. Temperature — composition phase diagrams are reported.
The results show that several liquid crystalline phases plus isotropic liquid, and two solid phases (a waxy solid phase and
a crystalline phase) are formed. Several types of water were detected: bulk-like water, interfacial water and hydration water.
Authors:P. Lavrenko, O. Okatova, K. Andreeva, and B. Schulz
Translational diffusion of poly-2,5-(1,3-phenylene)-1,3,4-oxadiazole (PMOD) in solution in 96% sulphuric acid was studied,
and intrinsic viscosity was measured at different stages of thermal degradation. Polymer solution has previously been subjected
to heating at temperature ranging from 75 to 104C and then investigated at 26C. A monotonic decrease in intrinsic viscosity
and the molecular mass, M, of degraded products with increasing degradation temperature was detected. The rate constant of the degradation process
has been obtained from the change in M of the degradation products with time at a fixed solution temperature, and the activation energy of the process was calculated
by using the temperature dependence of the rate constant. The activation energy (E =1028 kJ–1 ) is close to that obtained previously for the hydrolysis of poly-2,5-(1,4-phenylene)-1,3,4-oxadiazole (PPOD) in sulphuric
acid (106 kJ–1 ), the rate constant being approximately twice in the value.
Authors:P. Schulz, J. Rodríguez, F. Soltero-Martínez, J. Puig, and Z. Proverbio
The phase behaviour of the twin-tailed surfactant dioctadecyldimethylammonium bromide with water was studied by DSC, FT-IR,
X-ray and polarizing microscope. The phase diagram of DODAB-water system is very similar to that of DODAC-water. The dihydrate
is in equilibrium with isotropic solution below 55°C. Above this temperature there is a lamellar liquid crystalline region,
in equilibrium with isotropic liquid and solid crystals of DODAB·2H2O, up to 69°C. From 69 to 86°C, the lamellar mesophase is in equilibrium with ‘waxy’ anhydrous DODAB. From 86 to 116°C and
very high DODAB content, there is a very narrow region of existence of inverse hexagonal mesophase, in equilibrium via a narrow
biphase region with lamellar mesophase. AtT > 116°C an isotropic liquid appears. There seems to exist two different lamellar mesophases, one of them between 10 and 40
wt.% DODAB and the other between 60 and about 97 wt.% DODAB, with a biphase zone between them.
Authors:K. Aleklett, R. Brandt, M. Bronikowski, V. Butsev, B. Chasteler, G. Dersch, G. Feige, E. Friedlander, E. Ganssauge, G. Haase, J. Herrmann, D. Hoffman, B. Judek, P. Kosma, B. Kulakov, E. Langrock, D. Lee, W. Loveland, F. Pille, N. Porile, W. Schulz, and G. Seaborg
In recent years the question of the unusual behavior of projectile fragments formed in the interaction of relativistic heavy ions with copper nuclei was studied using nuclear chemistry techniques. As targets we used various copper disk arrangements. It is not the intention of this conference contribution to give a complete account of the entire procedure and its results. However, we want to present a few more recent experimental findings, some of them even in a preliminary form. We want to stimulate the discussion about the entire problem which might be part of the so-called anomalon phenomenon, as observed in the field of relativistic heavy ion interactions with a few other techniques such as nuclear emulsions or bubble chambers.