Lihui Zheng 1 Bin Liu 1 Huiyun Wang 2 Lingchen Kong 1 Jinhua Liu 2
1．MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing 102249, 2． Pharmaceutical Sciences of Jining Medical University, Rizhao Shandong 276826 email@example.com
Abstract: The ultrasonic micro-bubbles have been widely applied to drug domain such as the cardiovascular and cerebrovascular diseases, gene transfer, and the inhibiting for cancer cells proliferation, but very few people study on the microstructure of micro-bubbles. “Inner phase gas, inner surface of shell, viscous water, outer surface of shell, bulk water containing surfactant”, is called by the traditional structure was given by Sebba has been introduced in common with petroleum working fluids. Unfortunately, the traditional structure cannot explain the rheological properties, or provide strong evidences for the mechanism on blocking porous media. Therefore, the microstructure of micro-bubbles which were prepared by foamer, foam stabilizer and biopolymer was observed under the magnification of 1000-2000 diameters, and it was discovered that the micro-bubble microstructure consist of “gas core, surface tension reducing membrane, high viscosity layer, high viscosity fixing membrane, compatibility enhancing membrane, and concentration transition layer of polymer and surfactants” instead of the traditional one. So, the mechanisms were gotten for the rheological properties and were proved in practice. For illustrating, the medical micro-bubbles which were made by span and cholesterol for delivering Aspirin oral formulations were studied. It was indicated that the structure of medical micro-bubbles was different from thetraditional one under the magnification of 1000-2000 diameters. This discovery provided the base for further study on micro-bubble microstructure in medicine.
Key words: petroleum working fluids micro-bubble microstructure layer membrane