Effect of CaO on Fluorine in the Decomposition of REFCO_3

Influence of CaO on thermal decomposition of REFCO3 was studied. The results showed that CaO did not affect significantly the decomposition ratio of REFCO3. The XRD experiment showed that there was a great deal of CaF2 in the masting production, the gas chromatographic analysis on the gas of REFCO3 decomposed, and the 70% content of fluorine in the gas of REFCO3 added 15% CaO was reduced. CaO could absorb the fluorine from the decomposition of REFCO3, and the environmental pollution of the fluorine was greatly alleviated,

Fluid components in accessory minerals of Pan-African granitoids in the S■r Rondane Mountains, East Antarctica

Fluids （fluorine, chlorine, and OH） in accessory minerals （apatite, titanite and allanite） of Pan-African granitoids （Group-I granitoids, Group-II granitoids and Mefjell Plutonic Complex） from the Sor Rondane Mountains, East Antarctica were precisely measured by an electronic microprobe analyzer in this study. Apatites in the granites have commonly high fluorine contents. However, fluorine contents from the Group-Ⅰ, Group-Ⅱ granitoids and Mefjell Plutonic Complex （MPC） are of important variation, which F contents （3.21-7.20 wt%） in apatite from the Group-Ⅱ granitoids are much higher than those from the Group-Ⅰ granitoids （1.22-3.60 wt%） and the MPC （3.21-4.11 wt%）. Titanite in the MPC has a low fluorine content （0.23-0.50 wt%）, being less than those in the Group-Ⅰ granitoids （2.28 wt%） and Group-Ⅱ granitoids （1.85-2.78 wt%）. Fluorine in allanite in the Group-Ⅱ granitoids seems to have much lower contents than those from the Group-Ⅰ granitoids and the MPC. Higher fluorine contents in the titanite from the Group-Ⅱ granitoids may be mainly controlled by late-magmatic fluid-rock interaction processes associated with melt, but may not be indicative of original magma contents based on its petrographic feature, Due to very lower chlorine contents from all of accessory minerals, the authors suggest that titanite and apatite with higher fluorine contents in the Group-Ⅱ granitoids have much lower H2O （OH） contents compared with those in the Group-Ⅰ granitoids according to the partition among （F, Cl, OH）. Fluorine contents in whole-rock samples show a variation from the higher in the Group-Ⅰ granitoids to the lower in the Group-Ⅱ granitoids and the MPC, which are consistent with the changes of those from the biotite and hornblende as well as fluorite occurred in the Group-Ⅰ granitoids reported previously. Based on the above study of fluorine in accessory minerals and combined with the previous fluorine contents from biotites and hornblendes, the authors suggest that apatites and titanites with higher F contents in the Group-Ⅱ granitoids and the MPC may not be an indicator of higher fluorine contents in whole-rock, which reflect fluorine contents in magma sources and/or late-thermal activity. Higher fluorine contents in apatite, titanite and allanite may be an additional evidence of A-type affinity.

Alignment Mechanism of Liquid Crystal Molecules on the Fluorated Polyimide Surface

The generation of pretilt angles for nematic liquid crystal aligned on the rubbed polyimide surface containing trifluoromethyl moieties has been investigated. The characters of the rubbed polyimide films were studied by using X ray photoelectron spectroscopy(XPS) and atomic force microscopy(AFM). The uneven distribution extent of fluorine content along the depth of the polyimide films could be reduced by rubbing, thus the interaction between liquid crystal molecules and polyimide molecules decreased. It is also showed that the aggregation state of polyimide molecules was changed and polyimide chains aligned along the rubbing direction, so the orientation direction of the liquid crystal molecules was the same as the rubbing direction. The orientation effect of the liquid crystal molecules on the rubbed polyimide surface can be attributed to the combined effects of the Van der Waals dispersion interaction between polyimide and liquid crystal molecules, and the alignment of the orientation direction of polyimide chains with the rubbing direction.