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Physicochemical properties of surface charge-modified ZnO nanoparticles with different particle sizes.

Kim KM, Choi MH, Lee JK, Jeong J, Kim YR, Kim MK, Paek SM, Oh JM - Int J Nanomedicine (2014)

Bottom Line: The coating agents were determined to have attached to the ZnO surfaces through either electrostatic interaction or partial coordination bonding.Electrokinetic measurements showed that the surface charges of the ZnO nanoparticles were successfully modified to be negative (about -40 mV) or positive (about +25 mV).Although all the four types of ZnO nanoparticles showed some agglomeration when suspended in water according to dynamic light scattering analysis, they had clearly distinguishable particle size and surface charge parameters and well defined physicochemical properties.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Medical Chemistry, College of Science and Technology, Yonsei University, Gangwon-do, South Korea.

ABSTRACT
In this study, four types of standardized ZnO nanoparticles were prepared for assessment of their potential biological risk. Powder-phased ZnO nanoparticles with different particle sizes (20 nm and 100 nm) were coated with citrate or L-serine to induce a negative or positive surface charge, respectively. The four types of coated ZnO nanoparticles were subjected to physicochemical evaluation according to the guidelines published by the Organisation for Economic Cooperation and Development. All four samples had a well crystallized Wurtzite phase, with particle sizes of ∼30 nm and ∼70 nm after coating with organic molecules. The coating agents were determined to have attached to the ZnO surfaces through either electrostatic interaction or partial coordination bonding. Electrokinetic measurements showed that the surface charges of the ZnO nanoparticles were successfully modified to be negative (about -40 mV) or positive (about +25 mV). Although all the four types of ZnO nanoparticles showed some agglomeration when suspended in water according to dynamic light scattering analysis, they had clearly distinguishable particle size and surface charge parameters and well defined physicochemical properties.

No MeSH data available.


Related in: MedlinePlus

(A) Transmission electron microscopy images and (B) histogram and normal distribution from these images for (a) ZnOSM20(−), (b) ZnOSM20(+), (c) ZnOAE100(−), and (d) ZnOAE100(+).Notes: (A) 100 nm scale bar; (B) mean ± standard deviation of approximately 200 samples. The x-axis of (a) and (c) have the same scale as (b) and (d) respectively.
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f2-ijn-9-041: (A) Transmission electron microscopy images and (B) histogram and normal distribution from these images for (a) ZnOSM20(−), (b) ZnOSM20(+), (c) ZnOAE100(−), and (d) ZnOAE100(+).Notes: (A) 100 nm scale bar; (B) mean ± standard deviation of approximately 200 samples. The x-axis of (a) and (c) have the same scale as (b) and (d) respectively.

Mentions: The TEM results and particle size distributions obtained from the TEM images are shown in Figure 2. ZnOSM20(−), ZnOSM20(+), ZnOAE100(−), and ZnOAE100(+) had average primary particle sizes of 28, 32, 70, and 78 nm, respectively. All the particles had an irregular spherical shape, and no anisotropic growth was observed (Figure 2). The particle sizes of the uncoated ZnO nanoparticles were very similar to those of the coated ones (Figure S2). Size distribution histograms were obtained for 220±30 particles randomly selected from the TEM images (Figure 2B). Homogeneous and narrow size distributions were confirmed for all four types of coated ZnO nanoparticles. The histograms were further fitted to the normal distribution curve using Microsoft Excel®. The kurtosis and skewness values obtained lay in the ranges of −0.5∼0.2 and −0.10∼0.41, respectively, indicating that the size distributions were close to normal in spite of the slight inclination.


Physicochemical properties of surface charge-modified ZnO nanoparticles with different particle sizes.

Kim KM, Choi MH, Lee JK, Jeong J, Kim YR, Kim MK, Paek SM, Oh JM - Int J Nanomedicine (2014)

(A) Transmission electron microscopy images and (B) histogram and normal distribution from these images for (a) ZnOSM20(−), (b) ZnOSM20(+), (c) ZnOAE100(−), and (d) ZnOAE100(+).Notes: (A) 100 nm scale bar; (B) mean ± standard deviation of approximately 200 samples. The x-axis of (a) and (c) have the same scale as (b) and (d) respectively.
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Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4279853&req=5

f2-ijn-9-041: (A) Transmission electron microscopy images and (B) histogram and normal distribution from these images for (a) ZnOSM20(−), (b) ZnOSM20(+), (c) ZnOAE100(−), and (d) ZnOAE100(+).Notes: (A) 100 nm scale bar; (B) mean ± standard deviation of approximately 200 samples. The x-axis of (a) and (c) have the same scale as (b) and (d) respectively.
Mentions: The TEM results and particle size distributions obtained from the TEM images are shown in Figure 2. ZnOSM20(−), ZnOSM20(+), ZnOAE100(−), and ZnOAE100(+) had average primary particle sizes of 28, 32, 70, and 78 nm, respectively. All the particles had an irregular spherical shape, and no anisotropic growth was observed (Figure 2). The particle sizes of the uncoated ZnO nanoparticles were very similar to those of the coated ones (Figure S2). Size distribution histograms were obtained for 220±30 particles randomly selected from the TEM images (Figure 2B). Homogeneous and narrow size distributions were confirmed for all four types of coated ZnO nanoparticles. The histograms were further fitted to the normal distribution curve using Microsoft Excel®. The kurtosis and skewness values obtained lay in the ranges of −0.5∼0.2 and −0.10∼0.41, respectively, indicating that the size distributions were close to normal in spite of the slight inclination.

Bottom Line: The coating agents were determined to have attached to the ZnO surfaces through either electrostatic interaction or partial coordination bonding.Electrokinetic measurements showed that the surface charges of the ZnO nanoparticles were successfully modified to be negative (about -40 mV) or positive (about +25 mV).Although all the four types of ZnO nanoparticles showed some agglomeration when suspended in water according to dynamic light scattering analysis, they had clearly distinguishable particle size and surface charge parameters and well defined physicochemical properties.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Medical Chemistry, College of Science and Technology, Yonsei University, Gangwon-do, South Korea.

ABSTRACT
In this study, four types of standardized ZnO nanoparticles were prepared for assessment of their potential biological risk. Powder-phased ZnO nanoparticles with different particle sizes (20 nm and 100 nm) were coated with citrate or L-serine to induce a negative or positive surface charge, respectively. The four types of coated ZnO nanoparticles were subjected to physicochemical evaluation according to the guidelines published by the Organisation for Economic Cooperation and Development. All four samples had a well crystallized Wurtzite phase, with particle sizes of ∼30 nm and ∼70 nm after coating with organic molecules. The coating agents were determined to have attached to the ZnO surfaces through either electrostatic interaction or partial coordination bonding. Electrokinetic measurements showed that the surface charges of the ZnO nanoparticles were successfully modified to be negative (about -40 mV) or positive (about +25 mV). Although all the four types of ZnO nanoparticles showed some agglomeration when suspended in water according to dynamic light scattering analysis, they had clearly distinguishable particle size and surface charge parameters and well defined physicochemical properties.

No MeSH data available.


Related in: MedlinePlus