The effects of ionic emulsifier, sodium dodecylbenzene sulfate (SDBS), on the formation of the multihollow structures in sub-micron sized polymer particles produced by alkali/acid posttreatment were investigated. The ...The effects of ionic emulsifier, sodium dodecylbenzene sulfate (SDBS), on the formation of the multihollow structures in sub-micron sized polymer particles produced by alkali/acid posttreatment were investigated. The original latex particles with narrow size distribution were synthesized by a new sequence emulsifier-free/emulsifier emulsion copolymerization of styrene (St) and methacrylic acid (MAA). Results indicated that the pore size decreased and the pore number increased with the increase of SDBS amount, and the morphology of the posttreated latex particles was also significantly influenced by the introducing time of SDBS in the preparation of the original latex particles, and a suitable introducing time was 3 h of polymerization. (c) 2007 Cheng You Kan. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
In this work we report the measurement of the self-bias voltage of radiofrequency (RF) capacitevely coupled plasma, with a multihollow cathode and methane precursor, used for amorphous hydrogenated carbon (a- C:H) thi...In this work we report the measurement of the self-bias voltage of radiofrequency (RF) capacitevely coupled plasma, with a multihollow cathode and methane precursor, used for amorphous hydrogenated carbon (a- C:H) thin film deposition. The plasma is produced in the incident power and pressure ranges between 20 - 300 W and 10 - 100 mTorr, respectively. It was found that the self-bias voltage Vdc is a linear function of the square root of the incident power WRF. The relationship between the self-bias voltage and gas pressure P is established;this gives an empirical relation for (p/p0)y . From this result, the pressure p0 corresponding to the transition from hollow cathode effect to hollow cathode arc effect is determined.展开更多
文摘The effects of ionic emulsifier, sodium dodecylbenzene sulfate (SDBS), on the formation of the multihollow structures in sub-micron sized polymer particles produced by alkali/acid posttreatment were investigated. The original latex particles with narrow size distribution were synthesized by a new sequence emulsifier-free/emulsifier emulsion copolymerization of styrene (St) and methacrylic acid (MAA). Results indicated that the pore size decreased and the pore number increased with the increase of SDBS amount, and the morphology of the posttreated latex particles was also significantly influenced by the introducing time of SDBS in the preparation of the original latex particles, and a suitable introducing time was 3 h of polymerization. (c) 2007 Cheng You Kan. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
文摘In this work we report the measurement of the self-bias voltage of radiofrequency (RF) capacitevely coupled plasma, with a multihollow cathode and methane precursor, used for amorphous hydrogenated carbon (a- C:H) thin film deposition. The plasma is produced in the incident power and pressure ranges between 20 - 300 W and 10 - 100 mTorr, respectively. It was found that the self-bias voltage Vdc is a linear function of the square root of the incident power WRF. The relationship between the self-bias voltage and gas pressure P is established;this gives an empirical relation for (p/p0)y . From this result, the pressure p0 corresponding to the transition from hollow cathode effect to hollow cathode arc effect is determined.
