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Synthesis and analysis of photoresponsive side chain dendritic polyesters.

紀錄類型:	書目-語言資料,印刷品 : Monograph/item
書名/作者:	Synthesis and analysis of photoresponsive side chain dendritic polyesters.
作者:	Galgano, Joshua J.
面頁冊數:	104 p.
附註:	Source: Dissertation Abstracts International, Volume: 70-10, Section: B, page: 6238.
Contained By:	Dissertation Abstracts International70-10B.
標題:	Chemistry, Polymer.
標題:	Engineering, Chemical.
標題:	Engineering, Materials Science.
ISBN:	9781109458220
摘要、提要註:	The incorporation of a photoresponsive "smart" materials that can reversibly change shape or properties by simple photoirradiation, allow for components that are lighter and capable of responding faster than current adaptive materials. The azobenzene molecule observes an effective size differential when exposed to UV light on the order of ∼3.5 A as it converts from a stable trans isomer to an excited cis isomer. The isomerization is photoreversible when attenuated with visible light. Incorporating the azobenzene moiety into an extended polymer chain has resulted in such problems as lack of free volume available for the azobenzene to efficiently isomerize, increase in polymer chain rigidity, and the propensity for the azobenzene moieties to aggregate when forced into proximity with one another. Banthia et al. developed and incorporated a PAMAM dendritic wedge diol with a diacyl chloride azobenzene to form side chain dendritic polyesters (SCDPE).
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3383133

Synthesis and analysis of photoresponsive side chain dendritic polyesters.
Galgano, Joshua J.

Synthesis and analysis of photoresponsive side chain dendritic polyesters. - 104 p.

Source: Dissertation Abstracts International, Volume: 70-10, Section: B, page: 6238.

Thesis (Ph.D.)--The University of Iowa, 2009.

The incorporation of a photoresponsive "smart" materials that can reversibly change shape or properties by simple photoirradiation, allow for components that are lighter and capable of responding faster than current adaptive materials. The azobenzene molecule observes an effective size differential when exposed to UV light on the order of &sim;3.5 A as it converts from a stable trans isomer to an excited cis isomer. The isomerization is photoreversible when attenuated with visible light. Incorporating the azobenzene moiety into an extended polymer chain has resulted in such problems as lack of free volume available for the azobenzene to efficiently isomerize, increase in polymer chain rigidity, and the propensity for the azobenzene moieties to aggregate when forced into proximity with one another. Banthia et al. developed and incorporated a PAMAM dendritic wedge diol with a diacyl chloride azobenzene to form side chain dendritic polyesters (SCDPE).

ISBN: 9781109458220Subjects--Topical Terms:

423090
Chemistry, Polymer.

Synthesis and analysis of photoresponsive side chain dendritic polyesters.
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100 1 $a Galgano, Joshua J. $3 423232
245 1 0 $a Synthesis and analysis of photoresponsive side chain dendritic polyesters.
300 $a 104 p.
500 $a Source: Dissertation Abstracts International, Volume: 70-10, Section: B, page: 6238.
500 $a Adviser: David G. Rethwisch.
502 $a Thesis (Ph.D.)--The University of Iowa, 2009.
520 $a The incorporation of a photoresponsive "smart" materials that can reversibly change shape or properties by simple photoirradiation, allow for components that are lighter and capable of responding faster than current adaptive materials. The azobenzene molecule observes an effective size differential when exposed to UV light on the order of &sim;3.5 A as it converts from a stable trans isomer to an excited cis isomer. The isomerization is photoreversible when attenuated with visible light. Incorporating the azobenzene moiety into an extended polymer chain has resulted in such problems as lack of free volume available for the azobenzene to efficiently isomerize, increase in polymer chain rigidity, and the propensity for the azobenzene moieties to aggregate when forced into proximity with one another. Banthia et al. developed and incorporated a PAMAM dendritic wedge diol with a diacyl chloride azobenzene to form side chain dendritic polyesters (SCDPE).
520 $a Twelve SCDPE polymers were prepared in groups of increasing dendrimer generations (1st-3rd) and decreasing azobenzene concentrations (100%, 50%, 10%, and 5%) to confirm the proposed hypothesizes that the bulky dendrimer substituents provided efficient free volume to inhibit aggregation and increase the polymer photoresponse, and the increased flexibility gained from the decrease in azobenzene concentration would also elicit an increase in photoresponse. The polymers were analyzed as both solutions and as spin coated thin films. Real time UV-Vis spectroscopy isomerization kinetic showed that increasing the dendrimer generations for both solution and films increased the SCDPE polymer photoresponse. The decrease in azobenzene concentration resulted in increased photoresponse SCDPE polymer solutions, but showed no potential for SCDPE polymer films. Atomic force microscopy (AFM) was used to image 2nd and 3rd generation (100%) azobenzene SCDPE films with photoinduced surface relief gratings patterned on their surface with non polarized light. The difference in height variations (6 nm and 18 nm, respectively) confirmed the isomerization kinetic data that the 3 rd generation, 100% azobenzene film had the greatest potential for future applications. The films were also shown to be photoreversible with visible light which suggesting they have the potential to applications on photonic and optical photoresponsive devices.
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650 4 $a Engineering, Chemical. $3 423048
650 4 $a Engineering, Materials Science. $3 422974
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690 $a 0542
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710 2 $a The University of Iowa. $3 423213
773 0 $t Dissertation Abstracts International $g 70-10B.
790 1 0 $a Rethwisch, David G., $e advisor
790 $a 0096
791 $a Ph.D.
792 $a 2009
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