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Xu, Changgang
Publications (3 of 3) Show all publications
Wang, J., Xu, C., Nilsson, A. M., Fernandes, D. L. A. & Niklasson, G. A. (2019). A novel phase function describing light scattering of layers containing colloidal nanospheres. Nanoscale, 11(15), 7404-7413
Open this publication in new window or tab >>A novel phase function describing light scattering of layers containing colloidal nanospheres
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2019 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 11, no 15, p. 7404-7413Article in journal (Refereed) Published
Abstract [en]

Light scattering from small particles exhibit unique angular scattering distributions, which are strongly dependent on the radius to wavelength ratio as well as the refractive index contrast between the particles and the surrounding medium. As the concentration of the particles increases, multiple scattering becomes important. This complicates the description of the angular scattering patterns, and in many cases one has to resort to empirical phase functions. We have measured the angle dependence of light scattering from a polymer layer containing sub-micron metallic and dielectric particles. The samples exhibited strongly forward and backward peaked scattering patterns, which were fitted to a number of empirical approximative phase functions. We found that a novel two-term Reynolds-McCormick (TTRM) phase function gave the best fit to the experimental data in all cases. The feasibility of the TTRM approach was further validated by good agreement with numerical simulations of Mie single scattering phase functions at various wavelengths and sizes, ranging from the Rayleigh scattering regime to the geometrical optics regime. Hence, the widely adaptable TTRM approach is able to describe angular scattering distributions of different kinds of nanospheres and nanocomposites, both in the single scattering and multiple scattering regimes.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2019
National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-383188 (URN)10.1039/c9nr01707k (DOI)000465315900034 ()30938744 (PubMedID)
Funder
Swedish Research Council, 2016-03713
Available from: 2019-07-25 Created: 2019-07-25 Last updated: 2019-07-25Bibliographically approved
Wang, J., Xu, C., Nilsson, A. M., Fernandes, D. L. A., Strömberg, M., Wang, J. & Niklasson, G. (2018). General Method for Determining Light Scattering and Absorption of Nanoparticle Composites. Advanced Optical Materials, 6(4), Article ID 1801315.
Open this publication in new window or tab >>General Method for Determining Light Scattering and Absorption of Nanoparticle Composites
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2018 (English)In: Advanced Optical Materials, ISSN 2162-7568, E-ISSN 2195-1071, Vol. 6, no 4, article id 1801315Article in journal (Refereed) Published
Abstract [en]

Scattering and absorption from nanoparticles are of major importance in optical research as well as in a range of applications. The Kubelka–Munk two-flux radiative transfer model gives a simple description of light scattering in nanoparticle composite materials, but inversion of experimental transmittance and reflectance data to obtain backscattering and absorption coefficients remains challenging. Here, a general method for evaluating these parameters from transmittance and reflectance spectra, combined with spectral angle resolved light scattering measurements is developed. The angular dependence is approximatedby an extension of the empirical Reynolds–McCormick phase function, which is fitted to the experimental angle resolved light scattering data. This approach is verified by measurements on three typical nanoparticle/polymer composites containing plasmonic Au, ferromagnetic Fe3O4, and dielectric TiO2 particles. An approximation to the angular scattering pattern is further demonstrated, which can be applied to obtain the optical parameters using only reflectance and transmittance data, in cases where angle-resolved measurements are not available. These results can be extended to a wide range of isotropic, anisotropic, and multiple scattering systems, and will be highly useful in the fields of light scattering coatings/metamaterials, UV-shielding films, displays, absorption/scattering layers in solar cells and biological scatterers.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2018
National Category
Other Physics Topics Condensed Matter Physics
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-370103 (URN)10.1002/adom.201801315 (DOI)000459020300005 ()
Funder
Swedish Research Council, 2016-03713Swedish Research Council Formas, 221-2012-444
Available from: 2018-12-19 Created: 2018-12-19 Last updated: 2019-08-01Bibliographically approved
Xu, C., Carlsson, D. O. & Mihranyan, A. (2016). Feasibility of using DNA-immobilized nanocellulose-based immunoadsorbent for systemic lupus erythematosus plasmapheresis. Colloids and Surfaces B: Biointerfaces, 143, 1-6
Open this publication in new window or tab >>Feasibility of using DNA-immobilized nanocellulose-based immunoadsorbent for systemic lupus erythematosus plasmapheresis
2016 (English)In: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 143, p. 1-6Article in journal (Refereed) Published
Abstract [en]

The goal of this project was to study the feasibility of using a DNA-immobilized nanocellulose-based immunoadsorbent for possible application in medical apheresis such as systemic lupus erythematosus (SLE) treatment. Calf thymus DNA was bound to high surface area nanocellulose membrane at varying concentrations using UV-irradiation. The DNA-immobilized samples were characterized with scanning electron microscopy, atomic force microscopy, and phosphorus elemental analysis. The anti-ds-DNA IgG binding was tested in vitro using ELISA. The produced sample showed high affinity in vitro to bind anti-ds-DNA-antibodies from mice, as much as 80% of added IgG was bound by the membrane. Furthermore, the binding efficiency was quantitatively dependent on the amount of immobilized DNA onto nanocellulose membrane. The described nanocellulose membranes are interesting immunoadsorbents for continued clinical studies.

Keywords
Autoimmune diseases; DNA immobilization; Immunoadsorption; Nanocellulose; Systemic lupus erythematosus
National Category
Nano Technology
Identifiers
urn:nbn:se:uu:diva-287474 (URN)10.1016/j.colsurfb.2016.03.014 (DOI)000376696900001 ()27011345 (PubMedID)
External cooperation:
Funder
Knut and Alice Wallenberg FoundationGöran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of Technology
Available from: 2016-04-25 Created: 2016-04-25 Last updated: 2017-11-30Bibliographically approved
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