In Situ Accurate Analysis of Colloidal Nanoparticles via Four Wave Mixing

MRS Advances ◽  
2018 ◽  
Vol 3 (14) ◽  
pp. 707-709
Author(s):  
Jian Wu ◽  
Dao Xiang ◽  
Ching-Chung Hsueh ◽  
Jörg Rottler ◽  
Reuven Gordon
Keyword(s):  
Four Wave Mixing ◽  
In Situ Monitoring ◽  
Viscous Damping ◽  
Wave Mixing ◽  
Vibrational Modes ◽  
Accurate Analysis ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Dynamics Simulations

ABSTRACTFour-wave mixing (FWM) is used to measure the vibrational modes of nanoparticles in solution. The vibrations give information about the particle size, material properties and shape. This method has been used for in-situ monitoring of the growth of nanoparticles with high accuracy, as confirmed by electron microscopy analysis. We observe a threshold in the FWM signal which we believe is from a cavity forming around the nanoparticles that reduces viscous damping. We have observed this effect in molecular dynamics simulations as well.

Synthesis of PbS Semiconductor Microcrystallites In Situ in Reverse Micelles

1994 ◽  
Vol 358 ◽  
Author(s):  
O. De Sanctis ◽  
K. Kadono ◽  
H. Tanaka ◽  
T. Sakaguchi
Keyword(s):  
Particle Size ◽  
Reverse Micelles ◽  
Transition Energy ◽  
Four Wave Mixing ◽  
Nonlinear Property ◽  
Reversed Micelles ◽  
Wave Mixing ◽  
Spectroscopic Characteristics ◽  
Semiconductor Particles

ABSTRACTColloid semiconductor particles of PbS have been prepared in reversed micelles of AOT-heptane. The effects of the AOT, water and reactants concentrations have been studied. The initial crystallite size and its growth with the time aging are strongly dependent on the water/AOT ratio and the ionic pool concentration. The absorption spectroscopic characteristics of the PbS particles have been examined. As the particle size decreases the band gap shifts in color from orange-brown to yellow and approaches the transition energy of the first allowed excited state of a PbS molecule. Moreover, the optical nonlinear property of PbS particles was investigated by Degenerate Four-Wave Mixing (DFWM) experiment using a frequency-doubled Nd:YAG laser.

Evaluation of intercalation and interaction in in-situ polymerized PLA-HNT bionanocomposites

2020 ◽  
pp. 096739112092779
Author(s):  
P Manju ◽  
P Santhana Gopala Krishnan ◽  
SK Nayak
Keyword(s):  
Electron Microscopy ◽  
Halloysite Nanotubes ◽  
Poly Lactic Acid ◽  
Resonance Spectroscopy ◽  
Hydroxyl Groups ◽  
Scanning Calorimetry ◽  
Transmission Electron Microscopy Analysis ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

We report the in-situ synthesis of poly(lactic acid)–halloysite nanotubes (PLA-HNT) bionanocomposites, with a perspective to improve the interaction between PLA and HNT. Three PLA-HNT bionanocomposites with different HNT weight percentages were synthesized by polycondensation, followed by azeotropic distillation technique. Fourier transform infrared spectroscopy studies indicated the existence of hydrogen bonding between terminal hydroxyl groups of PLA and Si–O–Si groups present in the outer surface of HNT. Wide-angle X-ray diffraction, 29Si- and 27Al-nuclear magnetic resonance spectroscopy analysis confirmed the intercalation of PLA into HNT. Scanning electron microscopy analysis confirmed that there was no significant agglomeration and PLA matrix was found to be embedded with HNT. Transmission electron microscopy analysis also gave ample proof to substantiate the intercalation of PLA chains into HNT. Studies on zeta potential of PLA-HNT bionanocomposites, as compared with PLA, also confirmed the interactions between PLA and HNT. Single melting peak in differential scanning calorimetry analysis indicated the existence of one form of crystalline structure.

Fatigue of As-Fabricated Open Cell Aluminum Foams

2005 ◽  
Vol 127 (1) ◽  
pp. 40-45 ◽  
Author(s):  
J. Zhou ◽  
Z. Gao ◽  
A. M. Cuitino ◽  
W. O. Soboyejo
Keyword(s):  
Shear Bands ◽  
Digital Camera ◽  
Image Correlation ◽  
Ex Situ ◽  
Aluminum Foams ◽  
Open Cell ◽  
Strain Jump ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

This paper presents the results of the combined experimental investigation and digital image correlation (DIC) analysis of the fatigue failure of open cell aluminum foams. Compression–compression cyclic loads were applied to foam specimens under the as-fabricated condition. Following characterization of the S-N curve behavior, the macroscale deformation of the tested foam under fatigue was recorded using an in-situ digital camera. The deformation sequence was then analyzed using DIC technique. It was found that foams failed with an abrupt strain jump when shear bands were formed, and serious deformation up to more than 30% was developed in the center of the shear band. The ex-situ scanning electron microscopy analysis indicated that the abrupt strain jump was due to the microscale damage accumulation in struts where surface cracks were formed and propagated.

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