Physical properties of elongated inorganic nanoparticles

Krahne, Roman; Morello, Giovanni; Figuerola, Albert; George, Chandramohan; Deka, Sasanka; Manna, Liberato

doi:10.1016/j.physrep.2011.01.001

Cited by 144 publications

(139 citation statements)

References 620 publications

(998 reference statements)

Supporting

Mentioning

132

Contrasting

Unclassified

Order By: Relevance

“…Like QDs, they are considerably smaller than the wavelength of light, such that the local-field approximation applies, and, similar to nanowires, they have anisotropic optical properties. 21 Polarized emission and emission excitation have been demonstrated by single dot measurements on CdSe QRs 22 and CdSe/CdS dot-in-rods. 23 Opposite to the emission properties, experimental data on the absorption anisotropy of colloidal QRs and their possible correspondence to the predictions of the local-field approximation are rare.…”

Section: Introductionmentioning

confidence: 99%

Direct determination of absorption anisotropy in colloidal quantum rods

et al. 2012

View full text Add to dashboard Cite

We propose a direct method to determine absorption anisotropy of colloidal quantum rods. In this method, the rods are aligned in solution by using an alternating electric field and we measure simultaneously the resulting average change in absorption. We show that a frequency window for the electric field exists in which the change in absorbance as a function of field strength can be analyzed in terms of the quantum-rod dipole moment and the absorption coefficient for light that is polarized parallel or perpendicular to the long axis of the rod. The approach is verified by measuring the absorbance change of CdSe rods at 400 nm as a function of field strength, where we demonstrate excellent agreement between experiment and theory. This enables us to propose improved values for the CdSe quantum-rod extinction coefficient. Next, we analyze CdSe/CdS dot-in-rods and find that the absorption of the first exciton transition is fully anisotropic, with a vanishing absorption coefficient for light that is polarized perpendicularly to the long axis of the rods.

show abstract

Section: Introductionmentioning

confidence: 99%

Direct determination of absorption anisotropy in colloidal quantum rods

et al. 2012

View full text Add to dashboard Cite

show abstract

“…[19][20][21] In order to produce magnetic nanoaggregates with both controlled drug release kinetics and magnetic retention characteristics, it is necessary to control the collective properties of magnetic nanoaggregates. 22 In our study, the magnetic properties of nanoaggregates are dependent on the interparticulate interactions between the block copolymers and the beta-cyclodextrins; these interactions also have a significant effect on the nanoparticles' aggregation. 23 Drugs can be loaded into the nanoparticles' porous structures using two techniques: (1) postsynthesis, and (2) in-situ loading.…”

Section: Introductionmentioning

confidence: 72%

Controlled release of 5-fluorouracil and progesterone from magnetic nanoaggregates

Ragab¹,

Rohani²,

Consta³

2012

IJN

View full text Add to dashboard Cite

Background:The potential use of magnetic nanoparticles in biomedical applications has witnessed an exponential growth in recent years. Methods: In this study, we used nanoaggregates of magnetic nanoparticles as carriers for controlled drug delivery. The nanoaggregates are formed due to the presence of the block copolymer of polyethylene oxide-polypropylene oxide (Pluronic F-68) and beta-cyclodextrin that surround the magnetic core of the nanoparticles. The administration of the drug carriers occurs by inhalation, and the drug is delivered systemically via the pulmonary route. We tested the delivery of 5-fluorouracil and progesterone, which are used as models of hydrophilic and hydrophobic drugs, respectively. Results: The estimated nanoaggregates' diameters are between 293 nm ± 14.65 nm and 90.2 nm ± 4.51 nm, respectively. In-situ and post-synthesis techniques are two approaches for drug loading. The polymer composition of nanoaggregates and initial drug concentration showed a significant effect on both the drug entrapment efficiency and release kinetics. Average drug entrapment efficiencies ranged between 16.11% and 83.25%. In-situ loaded samples showed significantly slower release rates. The drug release mechanism is investigated by mathematical curve fitting to different drug release kinetics models. In most cases, the Peppas model has shown good correlations (coefficients of correlation, R 2 , between 0.85 and 0.99) with the examined release profiles. The estimated release indices are below 0.5, which indicates the Fickian diffusion mechanism. For samples with an initial burst effect, the modified Peppas model can provide a better understanding of the drug release mechanism, both in the samples loaded with progesterone, or those high polymer concentrations. Conclusion: Our work showed prolonged delivery of drugs (5-fluorouracil and progesterone) by diffusion from nanoaggregates, with the potential to reduce dose-related adverse effects.

show abstract

“…Removal of defects is an alternative way to increase the material strength. Nanosized crystals are an example of this [1][2][3]. However, new factor appears in this case, which influences strength essentially.…”

Section: Introductionmentioning

confidence: 99%

Relation between the strength and dimensionality of defect-free carbon crystals

Котречко¹,

Timoshevskii²,

Kolyvoshko³

et al. 2016

Nano Online

View full text Add to dashboard Cite

On the basis of ab initio simulations, the value of strength of interatomic bonds in one-, two-and three-dimensional carbon crystals is obtained. It is shown that decreasing in dimensionality of crystal gives rise to nearly linear increase in strength of atomic bonds. It is ascertained that growth of strength of the crystal with a decrease in its dimensionality is due to both a reduction in coordination number of atom and increase in the angle between the directions of atomic bonds. Based on these data, it is substantiated that the one-dimensional (1D) crystals have maximum strength, and strength of carbyne is the absolute upper limit of strength of materials.

show abstract

Physical properties of elongated inorganic nanoparticles

Cited by 144 publications

References 620 publications

Direct determination of absorption anisotropy in colloidal quantum rods

Direct determination of absorption anisotropy in colloidal quantum rods

Controlled release of 5-fluorouracil and progesterone from magnetic nanoaggregates

Relation between the strength and dimensionality of defect-free carbon crystals

Contact Info

Product

Resources

About