Anisotropic polymer nanoparticles with solvent and temperature dependent shape and size from triblock copolymers

2019 ◽  
Vol 10 (25) ◽  
pp. 3436-3443
Author(s):  
Elena Bobbi ◽  
Bassem Sabagh ◽  
Sally-Ann Cryan ◽  
James A. Wilson ◽  
Andreas Heise
Keyword(s):  
Triblock Copolymers ◽  
Polymer Nanoparticles ◽  
Spherical Particles ◽  
Temperature Dependent ◽  
Shape And Size

By the combination of RAFT and N-carboxyanhydride (NCA) polymerisation triblock copolymers were designed able to form responsive spherical and non-spherical particles.

scholarly journals Shape and size of non-spherical particles in single crystals, investigated by SAXS

1993 ◽  
Vol 03 (C8) ◽  
pp. C8-325-C8-328 ◽  
Author(s):  
F. LANGMAYR ◽  
O. PARIS ◽  
P. FRATZL
Keyword(s):  
Single Crystals ◽  
Spherical Particles ◽  
Shape And Size

Monitoring the spin crossover phenomenon of [Fe(2‐mpz) 2 Ni(CN) 4 ] 2D Hofmann‐type polymer nanoparticles via temperature‐dependent Raman spectroscopy

2020 ◽  
Vol 51 (11) ◽  
pp. 2171-2181 ◽  
Author(s):  
Zoi G. Lada ◽  
Konstantinos S. Andrikopoulos ◽  
Christina D. Polyzou ◽  
Vassilis Tangoulis ◽  
George A. Voyiatzis
Keyword(s):  
Raman Spectroscopy ◽  
Spin Crossover ◽  
Polymer Nanoparticles ◽  
Temperature Dependent

scholarly journals Thermoresponsive low-power light upconverting polymer nanoparticles

2016 ◽  
Vol 3 (6) ◽  
pp. 602-607 ◽  
Author(s):  
David C. Thévenaz ◽  
Angelo Monguzzi ◽  
Dimitri Vanhecke ◽  
Roberto Vadrucci ◽  
Francesco Meinardi ◽  
...  
Keyword(s):  
Low Power ◽  
Temperature Sensing ◽  
Live Cell ◽  
Polymer Nanoparticles ◽  
Temperature Dependent ◽  
Highly Efficient ◽  
Aqueous Conditions

Low-power upconverting nanoparticles are presented that display highly efficient, temperature-dependent green to blue upconversion under aerated aqueous conditions. These features are useful for live cell and in vivo temperature sensing.

Strength and Stiffness of Aluminum/PTFE Reactive Composites

2001 ◽  
Author(s):  
A. Saigal ◽  
V. S. Joshi
Keyword(s):  
High Strain ◽  
Three Dimensional ◽  
Element Model ◽  
Spherical Particles ◽  
Experimental Measurements ◽  
Aluminum Particles ◽  
Reactive Material ◽  
High Strain Rate Deformation ◽  
Strength And Stiffness ◽  
Shape And Size

Abstract Aluminum/Polytetrafluoroethylene mixtures are currently being studied as reactive material compositions, with focus on shock or impact ignition. In addition, there is an emphasis on increasing the strength of these composites to survive high strain-rate deformation. In this research, an analytical model, based on Eshelby’s approach, and a three-dimensional elastoplastic finite element model were developed along with experimental measurements to investigate the effect of the shape and size of aluminum: spherical particles, whiskers, and fibers, on the strength and stiffness of Aluminum/Polytetrafluoroethylene composites. It was found that the existing surface and size characteristics of aluminum particles (e.g. texturing) play an important role on the mechanical behavior of these composites.

Direct analysis of small-angle smeared intensity tails. II. Applications

1999 ◽  
Vol 32 (4) ◽  
pp. 590-599
Author(s):  
Salvino Ciccariello ◽  
Roger Sobry
Keyword(s):  
Asymptotic Expansion ◽  
Methyl Methacrylate ◽  
Small Angle ◽  
Particle Shape ◽  
Triblock Copolymers ◽  
Direct Analysis ◽  
X Ray ◽  
Poly Methyl Methacrylate ◽  
Shape And Size

The tails of the smeared small-angle X-ray intensities, scattered by two triblock copolymers of poly(methyl methacrylate-b-butadiene-b-methyl methacrylate) are analysed by using the smeared leading terms of the intensity asymptotic expansion. In this way, it is possible to determine the particle shape and size as well as the area and the Kirste–Porod curvosity of the sample interfaces.

SYNTHESIS AND ORGANIZATION OF II–VI LOW DIMENSION NANOMATERIALS IN NONIONIC AMPHIPHILIC TRIBLOCK COPOLYMER SYSTEMS

2003 ◽  
Vol 02 (04n05) ◽  
pp. 257-263 ◽  
Author(s):  
CHUNG-SUNG YANG ◽  
KUO-LUNG KU
Keyword(s):  
Aqueous Phase ◽  
Triblock Copolymer ◽  
Triblock Copolymers ◽  
Synthetic Route ◽  
Temperature Dependent ◽  
Znse Nanoparticles ◽  
Cds Nanorods ◽  
Amphiphilic Triblock Copolymer ◽  
Low Dimension ◽  
Selection Of

A new synthetic route to prepare II–VI nanoscale materials, such as CdS nanorods and ZnSe nanoparticles is demonstrated and the advantage of using nonionic triblock copolymer systems,i.e., H (– OCH 2 CH 2)x[– OCH ( CH 3)– CH 2]y(– OCH 2 CH 2)y– OH , or ( EO )x( PO )y( EO )x as structure-directing agents in the synthesis of low dimension nanomaterials is introduced. The effect of (EO)/(PO) ratio in controlling the diameter and the morphology of the final product is addressed. The employ of F127 [( EO )106( PO )70( EO )106] as a surfactant-template to study the temperature-dependent size-selection of ZnSe nanoparticles is also presented. We observe that the larger ZnSe nanoparticles are arrested first by the hydrophilic fractions of triblock copolymers F127, while the smaller particles still remain their thermal motion in the aqueous phase.

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

(111) Monocrystalline Nickel Films

1972 ◽  
Vol 30 ◽  
pp. 512-513
Author(s):  
T.E. Pratt ◽  
R.W. Vook
Keyword(s):  
Film Thickness ◽  
Deposition Rate ◽  
Room Temperature ◽  
Narrow Range ◽  
High Vacuum ◽  
Residual Pressure ◽  
Temperature Dependent ◽  
Deposition Parameters ◽  
Transmission Electron ◽  
Substrate Temperatures

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.

STEM Study of Surface Plasmon Excitation in Small Spherical Particles

1990 ◽  
Vol 48 (2) ◽  
pp. 42-43
Author(s):  
Daniel UGARTE
Keyword(s):  
Energy Loss ◽  
Spherical Particles ◽  
Small Particles ◽  
Bulk Materials ◽  
Low Loss ◽  
Plasmon Excitation ◽  
Surface Modes ◽  
Surface Plasmon Excitation ◽  
Analytical Electron ◽  
Analytical Electron Microscope

Small particles exhibit chemical and physical behaviors substantially different from bulk materials. This is due to the fact that boundary conditions can induce specific constraints on the observed properties. As an example, energy loss experiments carried out in an analytical electron microscope, constitute a powerful technique to investigate the excitation of collective surface modes (plasmons), which are modified in a limited size medium. In this work a STEM VG HB501 has been used to study the low energy loss spectrum (1-40 eV) of silicon spherical particles [1], and the spatial localization of the different modes has been analyzed through digitally acquired energy filtered images. This material and its oxides have been extensively studied and are very well characterized, because of their applications in microelectronics. These particles are thus ideal objects to test the validity of theories developed up to now.Typical EELS spectra in the low loss region are shown in fig. 2 and energy filtered images for the main spectral features in fig. 3.

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