國立虎尾科技大學 |

High-Pressure Study of Bio-inspired Multi-Functional Nanocomposites Using Atomic Force Microscopy Methods.

紀錄類型:	書目-語言資料,手稿 : Monograph/item
正題名/作者:	High-Pressure Study of Bio-inspired Multi-Functional Nanocomposites Using Atomic Force Microscopy Methods./
作者:	Diaz Gonzalez, Alfredo J.
面頁冊數:	1 online resource (140 pages)
附註:	Source: Dissertation Abstracts International, Volume: 78-12(E), Section: B.
Contained By:	Dissertation Abstracts International78-12B(E).
標題:	Mechanical engineering. -
電子資源:	click for full text (PQDT)
ISBN:	9780355092066

High-Pressure Study of Bio-inspired Multi-Functional Nanocomposites Using Atomic Force Microscopy Methods.
Diaz Gonzalez, Alfredo J.

High-Pressure Study of Bio-inspired Multi-Functional Nanocomposites Using Atomic Force Microscopy Methods. - 1 online resource (140 pages)

Source: Dissertation Abstracts International, Volume: 78-12(E), Section: B.

Thesis (D.Sc.)

Includes bibliographical references

Bioinspired design has been crucial in the development of new types of hierarchical nanocomposites. Particularly, the nacre-mimetic brick-and-mortar structure has shown excellent mechanical properties as well as gas barrier properties and optical transparency. Along with these intrinsic properties, the layered structure has been designed to serve as sensing devices. Here we expand the multi-functionality of nacre-mimetics by designing an optically transparent and electron conductive coating that reacts to high-pressure based on PEDOT:PSS and nanoclay. The main objectives of this project are: (i) to develop a multifunctional nanocomposite and evaluate the effect of high-pressure applied at the surface and (ii) to establish protocols for the morphological and structural characterization, and electro-mechanical testing of the nanocomposites based on a combination of atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmittance spectroscopy.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9780355092066Subjects--Topical Terms:

557493
Mechanical engineering.
Index Terms--Genre/Form:

554714
Electronic books.

High-Pressure Study of Bio-inspired Multi-Functional Nanocomposites Using Atomic Force Microscopy Methods.
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100 1 $a Diaz Gonzalez, Alfredo J. $3 1178981
245 1 0 $a High-Pressure Study of Bio-inspired Multi-Functional Nanocomposites Using Atomic Force Microscopy Methods.
264 0 $c 2017
300 $a 1 online resource (140 pages)
336 $a text $b txt $2 rdacontent
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338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertation Abstracts International, Volume: 78-12(E), Section: B.
500 $a Adviser: Santiago Solares.
502 $a Thesis (D.Sc.) $c The George Washington University $d 2017.
504 $a Includes bibliographical references
520 $a Bioinspired design has been crucial in the development of new types of hierarchical nanocomposites. Particularly, the nacre-mimetic brick-and-mortar structure has shown excellent mechanical properties as well as gas barrier properties and optical transparency. Along with these intrinsic properties, the layered structure has been designed to serve as sensing devices. Here we expand the multi-functionality of nacre-mimetics by designing an optically transparent and electron conductive coating that reacts to high-pressure based on PEDOT:PSS and nanoclay. The main objectives of this project are: (i) to develop a multifunctional nanocomposite and evaluate the effect of high-pressure applied at the surface and (ii) to establish protocols for the morphological and structural characterization, and electro-mechanical testing of the nanocomposites based on a combination of atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmittance spectroscopy.
520 $a The synthesis of the nanocomposite, containing PEDOT:PSS (conductive polymer) and nanoclay, was achieved using the self-assembly of core/shell platelets. Two different types of nanoclay, Cloisite Na+ and Laponite RD, are used and their properties compared. The reduction of thickness in PEDOT:PSS has been shown to increase the light transmittance across a film. Similarly, the thickness of the nanocomposite was reduced and compared to PEDOT:PSS. The measured optical transmittance for both nanocomposites is comparable to the bare polymer, demonstrating that the addition of the nanoclay does not affect the transparency of PEDOT:PSS significantly. The layered structure of the nanocomposites is investigated by imaging the fracture surface with SEM. The fracture surface of the Laponite RD based nanocomposite is much flatter than the Cloisite Na+ nanocomposite, since the particle size in Cloisite Na+ is about 10 times larger than Laponite RD. The characterization of electro-mechanical properties of the nanocomposites was performed using the correlation of conductive atomic force microscopy and contact resonance force microscopy to measure the local variations. The analysis shows that in thin and transparent films, there is segregation in the response of Cloisite Na+ based nanocomposites compared to the bare polymer or Laponite RD nanocomposite, hence the investigation focuses on Laponite RD.
520 $a For Laponite RD, we investigate the 3-D distribution of nanoclay in the coating. The distribution of nanoclay at the surface is elucidated by mapping the dissipative and conservative interactions between tip and sample in bimodal AFM. Measuring the strain produced by the tip, the 3-D structure is inferred using models for mechanical properties of nanocomposites. Single platelet measurements are used to infer the inter-platelet distance. It is known that the free amplitude of the higher eigenmode can be modulated to produce large forces in bimodal AFM. The pressure estimated for the typical cantilever parameters used are in the range 1.2-3.3 GPa, which is used to apply high-pressure to the subsurface structure of the nanocomposite.
520 $a We show that the tip-surface interaction modifies the subsurface morphology of the nanocomposite and results in changes of the out-of-plane current. Also, the structural modification caused by the bimodal AFM treatment results in local changes in mechanical properties. This behavior is obtained for the Laponite RD nanocomposite, but it is not observed for the Cloisite Na+ nanocomposite or the bare polymer. Laponite RD has a platelet size similar to the tip, while Cloisite Na+ is much larger leading to a reduction in pressure. By modelling the transmission probability of electrons, geometrical changes in the structure are examined and shown to modify the tunneling of the electrons through the coating. Specifically, parallel compression of the nanoclay (modelled as barriers for electrons) leads to a change in the transmission probability of the electrons. Depending on the kinetic energy of the electrons, the transmission probability could either increase or decrease.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Mechanical engineering. $3 557493
650 4 $a Nanoscience. $3 632473
655 7 $a Electronic books. $2 local $3 554714
690 $a 0548
690 $a 0565
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a The George Washington University. $b Mechanical & Aerospace Engineering. $3 1178982
773 0 $t Dissertation Abstracts International $g 78-12B(E).
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10601552 $z click for full text (PQDT)