排序方式: 共有45条查询结果,搜索用时 15 毫秒
41.
Thurecht KJ Gregory AM Villarroya S Zhou J Heise A Howdle SM 《Chemical communications (Cambridge, England)》2006,(42):4383-4385
This report presents the first simultaneous, metal-free synthesis of block copolymers through combination of enzymatic ring-opening polymerisation of epsilon-caprolactone with RAFT-mediated controlled radical polymerisation of styrene. 相似文献
42.
Wang J Khlobystov AN Wang W Howdle SM Poliakoff M 《Chemical communications (Cambridge, England)》2006,(15):1670-1672
A facile and efficient method has been developed for coating MWNTs with solvent resistant polymer in scCO2, which permits the selective deposition of high molecular weight fluorinated graft poly(methyl vinyl ether-alt-maleic anhydride) polymer onto MWNTs in scCO2 under 100-170 bar at 40 degrees C and forms quasi one-dimensional nanostructures with conducting cores and insulating surfaces. 相似文献
43.
Ronny Pini Giuseppe Storti Marco Mazzotti Hongyun Tai Kevin M. Shakesheff Steven M. Howdle 《Journal of Polymer Science.Polymer Physics》2008,46(5):483-496
Tissue engineering scaffolds require a controlled pore size and structure to host tissue formation from cell populations. Supercritical carbon dioxide (scCO2) processing can be used to form porous scaffolds in which the escape of CO2 from a plasticized polymer melt generates gas bubbles that shape the pores. The process is difficult to control with respect to changes in final pore size, porosity, and interconnectivity, while the solubility of CO2 in the polymers strongly affects the foaming process. An in‐depth understanding of polymer CO2 interaction will enable a successful scaffold processing. Amorphous poly(DL ‐lactic acid) (PDL LA) and poly(lactic acid‐co‐glycolic acid) (PLGA) polymers are attractive candidates for fabricating scaffolds. In this study, CO2 sorption and swelling isotherms at 35 °C and up to 200 bar on a variety of homo‐ and copolymers of lactic acid and glycolic acids are presented. Sorption is measured through a gravimetric technique using a suspension microbalance and swelling by visualization. The obtained results are modeled using the Sanchez‐Lacombe equation of state. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 483–496, 2008 相似文献
44.
Maximizing nonlinear light-matter interactions is a primary motive for compressing laser pulses to achieve ultrashort transform limited pulses. Here we show how, by appropriately shaping the pulses, resonant multiphoton transitions can be enhanced significantly beyond the level achieved by maximizing the pulse's peak intensity. We demonstrate the counterintuitive nature of this effect with an experiment in a resonant two-photon absorption, in which, by selectively removing certain spectral bands, the peak intensity of the pulse is reduced by a factor of 40, yet the absorption rate is doubled. Furthermore, by suitably designing the spectral phase of the pulse, we increase the absorption rate by a factor of 7. 相似文献
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