scholarly journals Structure Sensitivity of Carbon−Nitrogen Ring Opening: Impact of Platinum Particle Size from below 1 to 5 nm upon Pyrrole Hydrogenation Product Selectivity over Monodisperse Platinum Nanoparticles Loaded onto Mesoporous Silica

2008 ◽  
Vol 130 (43) ◽  
pp. 14026-14027 ◽  
Author(s):  
John N. Kuhn ◽  
Wenyu Huang ◽  
Chia-Kuang Tsung ◽  
Yawen Zhang ◽  
Gabor A. Somorjai
Keyword(s):  
Particle Size ◽  
Mesoporous Silica ◽  
Platinum Nanoparticles ◽  
Ring Opening ◽  
Structure Sensitivity ◽  
Hydrogenation Product ◽  
Platinum Particle ◽  
Product Selectivity ◽  
Nitrogen Ring

Direct manipulation of particle size and morphology of ordered mesoporous silica by flow synthesis

RSC Advances ◽  
2015 ◽  
Vol 5 (18) ◽  
pp. 13331-13340 ◽  
Author(s):  
T. N. Ng ◽  
X. Q. Chen ◽  
K. L. Yeung
Keyword(s):  
Particle Size ◽  
Mesoporous Silica ◽  
Hollow Spheres ◽  
Ordered Mesoporous Silica ◽  
Direct Manipulation ◽  
Flow Synthesis ◽  
Precise Control ◽  
Ordered Mesoporous ◽  
Particle Size And Morphology ◽  
Size And Morphology

Flow-synthesis of mesoporous silica allows deliberate and precise control over the size and shapes and enables the preparation of complex microstructures (i.e., hollow spheres).

Platinum nanoparticles encapsulated in mesoporous silica: Preparation, characterisation and catalytic activity in toluene hydrogenation

2005 ◽  
Vol 86 (1-3) ◽  
pp. 198-206 ◽  
Author(s):  
Svatopluk Chytil ◽  
Wilhelm R. Glomm ◽  
Elisabeth Vollebekk ◽  
Håkon Bergem ◽  
John Walmsley ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Mesoporous Silica ◽  
Platinum Nanoparticles ◽  
Toluene Hydrogenation

Preparation of mesoporous silica-based nanocomposites with synergistically antibacterial performance from nano-metal (oxide) and polydopamine

2021 ◽  
Author(s):  
Guofeng Su ◽  
Ximing Zhong ◽  
Songfa Qiu ◽  
Jiajin Fan ◽  
hongjun zhou ◽  
...  
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Mesoporous Silica ◽  
Synergistic Effect ◽  
Practical Applications ◽  
Antibacterial Performance ◽  
Large Size ◽  
Zinc Oxides ◽  
Nanocomposite System ◽  
Nano Zinc

Abstract In this work, a novel antibacterial nanocomposite system was developed using mesoporous silica (MSN) as an effective nanocarrier, and the resultant nanocomposites demonstrated remarkable antibacterial performance due to the synergistic effect among nano zinc oxides, silver nanoparticles, and polydopamine (PDA). The successful synthesis of MSN/ZnO@PDA/Ag nanocomposites was confirmed. The physicochemical properties and the morphologies of these nanocomposites were investigated. It was found that the particle size increased along with the evolution of these nanocomposites. Besides, nano zinc oxides were formed in the nanoconfinement channel of mesoporous silica with a particle size about 2 nm, and that of silver nanoparticle was less than 50 nm. In addition, the results revealed that the presence of mesoporous silica could effectively prevent the formation of large-size silver nanoparticles and facilitate their well dispersion. Due to the synergistic effect among nano zinc oxides, silver nanoparticles, and polydopamine, these nanocomposites exhibited remarkable antibacterial performance even at a low concentration of 313 ppm, and the antibacterial mechanism was also elucidated. Therefore, this work provides a facile and controllable approach to preparing synergistically antibacterial nanocomposites, and the remarkable antibacterial performance make them suitable for practical applications.

Blood clot initiation by mesoporous silica nanoparticles: dependence on pore size or particle size?

2016 ◽  
Vol 4 (44) ◽  
pp. 7146-7154 ◽  
Author(s):  
Zihao Chen ◽  
Fan Li ◽  
Changjun Liu ◽  
Jing Guan ◽  
Xiao Hu ◽  
...  
Keyword(s):  
Particle Size ◽  
Mesoporous Silica ◽  
Pore Size ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Blood Clot

The hemostatic efficiency of mesoporous silica nanoparticles depends on pore size more than particle size, and biocompatibility is more related to particle size.

scholarly journals Citrate-Coated Platinum Nanoparticles Exhibit a Primary Particle-Size Dependent Effect on Stimulating Melanogenesis in Human Melanocytes

Cosmetics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 88
Author(s):  
Shilpi Goenka ◽  
Jimmy Toussaint
Keyword(s):  
Particle Size ◽  
Platinum Nanoparticles ◽  
Primary Particle ◽  
Primary Particle Size ◽  
Hair Follicles ◽  
Catechol Oxidase ◽  
Personal Care ◽  
Free System ◽  
White Skin ◽  
Human Melanocytes

Hypopigmentation disorders due to an underproduction of the pigment melanin by melanocytes cause uneven skin coloration, while in hair follicles they cause grey hair. There is a need for novel materials which can stimulate melanogenesis in the skin and hair for personal care use. While titanium dioxide, gold and silver nanoparticles have been extensively used for applications in cosmetic and personal-care products (PCP), the use of relatively inert platinum nanoparticles (PtNPs) has remained underappreciated. PtNPs have been reported to be a mimetic of the enzyme catechol oxidase with small size PtNPs reported to exhibit a higher catechol oxidase activity in a cell-free system, but no testing has been conducted in melanocytes to date. Herein, we have investigated if PtNPs of two sizes (SPtNP: 5 nm; LPtNP: 50 nm) might have an effect on melanogenesis. To this end, we have used MNT-1 human melanoma cells and primary human melanocytes from moderately-pigmented skin (HEMn-MP). Both SPtNP and LPtNP were nontoxic over a concentration range 6.25–25 μg/mL, hence these concentrations were used in further experiments. Both PtNPs stimulated higher extracellular melanin levels than control; SPtNP at concentrations 12.5 and 25 μg/mL significantly stimulated higher levels of extracellular melanin as compared to similar concentrations of LPtNP in MNT-1 cells, in the absence of ROS generation. The effects of PtNPs on melanin secretion were reversible upon removal of PtNPs from the culture medium. The results of primary particle size-specific augmentation of extracellular melanin by SPtNPs were also validated in HEMn-MP cells. Our results thus provide a proof-of-principle that SPtNP might hold potential as a candidate for the treatment of white skin patches, for sunless skin-tanning and for use in anti-greying hair products in cosmetics.

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