Peculiarities of Electron-Beam Formation of Hydrophobic and Superhydrophobic Coatings Based on Hydrocarbons of Various Molecular Weights and PTFE

The paper studies the possibility of superhydrophobic coatings formations at exposure of powder mixture of polytetrafluorethylene and hydrocarbons having various molecular weights to low-energy electron beam in vacuum. It is shown that paraffin and PTFE based thin composite coatings may be characterized by superhydrophobic properties. The superhydrophobic properties are attained due to low surface energy of the fluorine-containing component and structured surface due to peculiarities of composite layer formation. The chemical processes observed in electron beam exposed area determine the molecular structure, morphology and the contact angle of thin organic coatings deposited. It is shown that high-molecular-weight hydrocarbon compounds should not be recommended for vacuum electron-beam deposition of superhydrophobic thin coatings because of deep changes in the molecular structure exposed to electron beam. These processes are responsible for high degree of unsaturation of the thin layer formed and for occurrence of oxygen-containing polar groups. The influence of substrate temperature on molecular structure, morphology and hydrophobic properties of thin coatings deposited is investigated. Potentially such coatings may be applied for deposition on the surface of metal capillaries used in biotechnological analyzers

The effectiveness of radiofrequency ablation for varicose veins treatment

Varicous veins are very common for Russian population. The disease is an important cause of morbidity and it also negatively impact patients' quality of life. The management of it can be conservative or surgical.Open surgery has been the gold-standart treatment for varicose veins since the late 1800s, when Friedrich von Trendelenburg perfomed a med-thigh open ligation. Over the last 15 years surgical treatment has been moving towards minimally invasive endovascular techniques, less invasive than conventional surgery

Radiofrequency ablation as effective method of treatment for varicose veins of lower extremities

Radiofrequency ablation (RFA) is the modern endovenous thermal method of treatment for varicose veins (VV) of the lower extremities which is characterized by high selective influence on patholologically changed vein. Intraoperative duplex sonography (DS) as an integral part of operation provides the precision of RFA treatment. The above-stated endovenous method is miniinvasive and is carried out under tumescent anesthesia. In comparison with phlebectomy complications are rare. 150 patients, both sexes, 60% (n=90) women, 40% (n=60) men were included in this research. In preoperative period all patients underwent DS. Visual analog scale (VAS), questionnaires of quality of life and sufficiency of treatment were used to asses the effectiveness of RFA and proved suprime results in treatment of VV of the lower extremities. RFA can be recommended as alternative to phlebectomy. © Published under licence by IOP Publishing Ltd