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1

SANS Study of Poly(ethylene glycol) Solutions in D_2O

100%

Lancz G., Avdeev M., Petrenko V., Garamus V., Koneracká M., Kopčanský P.

Acta Physica Polonica A

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2010

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vol. 118

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issue 5

980-982

EN

Poly(ethylene glycol) is used for coating of colloidal particles and other surfaces for gaining biocompatibility. Particularly, it can be introduced into magnetic fluids. The aim of the current study was to reveal the structural characteristics of poly(ethylene glycol) in neat D_2O using small-angle neutron scattering technique. Solutions of poly(ethylene glycol) (at temperature of 37°C) with different molecular weights in an interval of 400-20000 were investigated. It is concluded that at low concentrations (less than 2% of mass fraction) poly(ethylene glycol) molecules behave as Gaussian coils.

2

Structure of Dilute Micellar Water Solutions of Nonionic Dimeric Surfactant Study by Small Angle Neutron Scattering Method

100%

Rajewska A., Wilk K.

Acta Physica Polonica A

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2014

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vol. 126

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issue 6

1272-1274

EN

The new sugar gemini nonionic surfactant - bis(C12LA) [(C_{56}H_{110}N_{4}O_{22})] was investigated by small angle neutron scattering method for six dilute solutions with concentrations: 20 CMC, 50 CMC, 75 CMC, 100 CMC, 125 CMC and 150 CMC (CMC = 7.3×10^{-6} mol/dm^{3}, CMC = critical micellar concentration) and three temperatures (20°C, 40°C and 60°C) for the q range 0.003-0.4 Å^{-1}. The aim of experiment was to determine the size and shape of micelles as a function of concentration and temperature in heavy water micellar solutions of nonionic dimeric surfactant bis(C12LA).

3

In Situ Neutron Diffraction Characterization of Phases in Co-Re-Based Alloys at High Temperatures

100%

Strunz P., Mukherji D., Gilles R., Gasser U., Beran P., Farkas G., Hofmann M., Karge L., Rösler J.

Acta Physica Polonica A

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2015

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vol. 128

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issue 4

684-688

EN

Co-Re-based alloys strengthened by carbides are promising candidates for new high-temperature alloys for gas turbine applications. The high temperature microstructure and its stability are of utmost importance, e.g. due to strengthening-phase selection. Neutron scattering, providing in situ information at high temperatures, was extensively used in the past for the Co-Re alloys research. The paper focuses on TaC strengthened alloy, particularly on the stability TaC precipitates which were previously shown not to dissolve up to at least 1300°C. Small-angle neutron scattering shows that its finer morphological variant - most suitable for high temperature strengthening - coarsened even at relatively low temperature of 1000°C. This coarsening is faster at higher temperatures and the mean size exceeded 1000 Å (i.e. the size - detection limit of the used facility) after 4 h hold at 1200°C.

4

Microstructure of Zirconia-Based Sol-Gel Glasses Studied by SANS

80%

Ryukhtin V., Strunz P., Kopitsa G., Ezdakova K., Gubanova N., Ivanov V., Baranchikov A., Angelov B., Feoktistov A., Pipich V., Levinský P.

Acta Physica Polonica A

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2015

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vol. 128

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issue 4

582-584

EN

Zirconia-based bulk glasses were prepared for the first time by sol-gel method. Such materials are very promising for application as photochromic devices, catalytic systems, chemical sensors, lasers and other nonlinear optics devices. Obtained transparent and semi-transparent materials were studied by small and ultra-small angle neutron scattering (SANS and USANS) methods. As evidenced by SANS, morphology of zirconia glasses is very sensitive to parameters of sol-gel synthesis, e.g. temperature and concentration of reactants. SANS data correlates rather well with surface porosity data. Increasing water concentration in reaction mixtures containing zirconium propylate leads to a significant increase in fractal cluster size, while decrease of the temperature results in an increase of the fractal dimension. The obtained results indicate that parameters of the microstructure and consequently physical properties of zirconia glasses can be effectively controlled by parameters of synthesis.

5

Short Range Order in Polymers within Neutrons' Eyeshot

80%

Zając W.

Acta Physica Polonica A

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2009

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vol. 115

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issue 2

594-598

EN

The paper presents a short review of neutron scattering results obtained during investigation of short range order in bulk polymers. Neutron scattering proves exceptionally powerful in this type of study through (i) large penetration depth of bulk samples, (ii) isotope sensitivity, and (iii) the use of spin polarization technique. The examples provided deliver results that can hardly be obtained from e.g. X-ray diffraction.

6

How Random Is a Random Polymer Coil?

80%

Zając W.

Acta Physica Polonica A

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2012

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vol. 121

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issue 2

464-467

EN

Short range order within amorphous, random polymer structures is a well known and widely studied property of disordered systems. An aggregate of five random atactic chains, each comprising 400 building units was computer-generated and then used to calculate neutron coherent scattering intensity for 0.01 < Q < 30 nm^{-1} (0.001 < Q < 3 Å^{-1}). The latter was compared with experimental data within the diffuse scattering range. On the grounds of quantum chemical calculations for an atactic polystyrene tetramer and the above information it is concluded that interactions among phenyl rings are responsible for the onset of the local order in this polymer.

Refine search results

SANS Study of Poly(ethylene glycol) Solutions in D_2O

Structure of Dilute Micellar Water Solutions of Nonionic Dimeric Surfactant Study by Small Angle Neutron Scattering Method

In Situ Neutron Diffraction Characterization of Phases in Co-Re-Based Alloys at High Temperatures

Microstructure of Zirconia-Based Sol-Gel Glasses Studied by SANS

Short Range Order in Polymers within Neutrons' Eyeshot

How Random Is a Random Polymer Coil?