Static and dynamic light scattering studies of water‐in‐oil microemulsions in the critical region. Evidence of a crossover effect

The aim of this work is the synthesis of calcium carbonate (CaCO3) nano and microparticles and their application as biomaterials (vehicles) for the sustained release of doxycycline. CaCO3 micro particles were synthesized by water-in oil (W/O) emulsion method using emulsion liquid membranes with bis (2-ethylhexyl) phosphate (D2EHPA) as carrier, Span 80 as surfactant, and toluene and kerosene as organic solvents. The aqueous phases contained 1 M CaCl2, and 1 M Na2CO3, respectively. The Dynamic Light Scattering (DLS) data showed CaCO3 particles with sizes ranging from around 100 nm to 3500 nm. The CaCO3 particles with the average diameters around 600 nm attained an adsorbtion of doxycycline of maximum 97.9%, and a slow and steady release with a cumulative value of approximative 50% after ten days.

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Pitfalls and novel applications of particle sizing by dynamic light scattering

Biomaterials ◽

10.1016/j.biomaterials.2016.05.003 ◽

2016 ◽

Vol 98 ◽

pp. 79-91 ◽

Cited By ~ 58

Author(s):

Karl Fischer ◽

Manfred Schmidt

Keyword(s):

Light Scattering ◽

Dynamic Light Scattering ◽

Particle Sizing ◽

Novel Applications

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Limitations of Nanoparticles Size Characterization by Asymmetric Flow Field‑Fractionation Coupled with Online Dynamic Light Scattering

Chromatographia ◽

10.1007/s10337-020-03997-7 ◽

2021 ◽

Author(s):

Francesco Giorgi ◽

Judith M. Curran ◽

Douglas Gilliland ◽

Rita La Spina ◽

Maurice Whelan ◽

...

Keyword(s):

Light Scattering ◽

Dynamic Light Scattering ◽

Flow Field ◽

Field Flow Fractionation ◽

Asymmetric Flow ◽

Uv Detector ◽

Elution Time ◽

On Line ◽

Real Size ◽

Flow Fractionation

AbstractThe development of reliable protocols suitable for the characterisation of the physical properties of nanoparticles in suspension is becoming crucial to assess the potential biological as well as toxicological impact of nanoparticles. Amongst sizing techniques, asymmetric flow field flow fractionation (AF4) coupled to online size detectors represents one of the most robust and flexible options to quantify the particle size distribution in suspension. However, size measurement uncertainties have been reported for on-line dynamic light scattering (DLS) detectors when coupled to AF4 systems. In this work we investigated the influence of the initial concentration of nanoparticles in suspension on the sizing capability of the asymmetric flow field-flow fractionation technique coupled with an on-line dynamic light scattering detector and a UV–Visible spectrophotometer (UV) detector. Experiments were performed with suspensions of gold nanoparticles with a nominal diameter of 40 nm and 60 nm at a range of particle concentrations. The results obtained demonstrate that at low concentration of nanoparticles, the AF4-DLS combined technique fails to evaluate the real size of nanoparticles in suspension, detecting an apparent and progressive size increase as a function of the elution time and of the concentration of nanoparticles in suspension.

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