Authors:Z. A. Siddiqui, A. Khan, M. R. Khan, and E. F. Abd-Allah
. 29 , 221 – 236 .
Anita , S. , Ramachandran, T. , Koushik , C. V. , Rajendran , R. and Mahalakshmi , M. ( 2010 ): Preparation and characterization of zinc oxide nanoparticles and a study of their antibacterial property of cotton fabric
Authors:Grażyna Janowska, Teresa Mikołajczyk, Dorota Wołowska-Czapnik, and M. Boguń
The paper discusses the thermal properties of alginate fibres made from alginic acid or sodium alginate and from alginates
substituted with divalent metal ions during the fibre-forming stage. Alginate fibres with an addition of silica nanoparticles
have also been examined. The selection of fibre-forming parameters was intended to obtain the best either sorption or strength
properties depending on the specific fibre application. Thermal curves of the fibres under investigations obtained by under
air atmosphere and differential scanning calorimetry (DSC) under neutral gas atmosphere have been interpreted from the view
of physical and chemical changes in the fibre-forming material. Based on thermogravimetric curves, the fibre thermal stability
indices have been determined. It has been found that the addition of silica nanoparticles exerts a positive influence on the
thermal properties of the examined fibres.
Plasmon-resonant nanoparticles are being integrated into a variety of actuators, sensors and calorimeters due to their extraordinary
optical capabilities. We show a continuum energy balance accurately describes thermal dynamics and equilibrium temperatures
in plasmon-resonant nanoparticle systems. Analysis of 18 data sets in which temperature increased ≤10.6 °C yielded a mean
value of R2 > 0.99. The largest single relative temperature error was 1.11%. A characteristic temperature was introduced into a linear
driving force approximation for radiative heat transfer in the continuum energy description to simplify parameter estimation.
The maximum percent error of the linearized description rose to 1.5% for the 18 sets. Comparing the two descriptions at simulated
temperature increases up to 76.6 °C gave maximum relative errors ≤7.16%. These results show for the first time that the energy
balance and its linearized approximation are applicable to characterize dynamic and equilibrium temperatures for sensors,
actuators and calorimeters containing nanoparticles in microfluidic and lab-on-chip systems over a broad range of heat-transfer
lengths, power inputs and corresponding temperature increases.
Authors:U. B. Gawas, V. M. S. Verenkar, and S. C. Mojumdar
Tartaj , P , Morales , MDP , Veintemillas-Verdaguer , S , Gonzáalez-Carreño , T , Serna , CJ . The preparation of magnetic nanoparticles for applications in biomedicine . J Phys D . 2003 ; 36R : 182 – 197 . 10
Recently, it was reported that the toxicity of copper particles increases with the decrease of the particle size on a mass
basis. To understand this phenomenon, inductively coupled plasma mass spectrometry (ICP-MS) techniques and in vitro chemical
studies were carried out to explore how they produce toxicity in vivo. The results suggest that when the sizes of particles
become small and down to a nanoscale, copper becomes extremely reactive in a simulative intracorporeal environment. The nanosized
copper particles consume the hydrogen ions in stomach more quickly than micron ones. These processes further convert the copper
nanoparticles into cupric ions whose toxicity is very high in vivo.
Authors:Ai-Yih Wang, Chun-Liang Kuo, Jiunn-Liang Lin, Chao-Ming Fu, and Yuh-Feng Wang
This study examined the applications of novel non-polymer magnetic ferrite nanoparticles (Fe3O4 NPs) labeled with 99mTc-pertechnetate (99mTcO4−). The radiochemistry, chemistry, and biodistribution of Fe3O4 NPs labeled with 9mTcO4− were analyzed. This paper employed instant thin layer chromatography and magnetic adsorption to evaluate the labeling efficiency
and stability of 99mTc-Fe3O4 at various reaction conditions. A scanning electron microscope, X-ray diffractometer, Fourier transform infrared spectrometer,
laser particle size analyzer, and superconducting quantum interference device magnetometer were used to analyze the physical
and chemical properties of the Fe3O4 and 99Tc-Fe3O4 nanoparticles. The biodistribution and excretion of 99mTc-Fe3O4 were also investigated. Radiochemical analyses showed that the labeling efficiency was over 92% after 1 min in the presence
of a reducing agent. Hydroxyl and amine groups covered the surface of the Fe3O4 particles. Therefore, 99Tc (VII) reduced to lower oxidation states and might bind to Fe3O4 NPs. The sizes of the 99Tc-Fe3O4 NPs were about 600 nm without ultrasound vibrations, and the particle sizes were reduced to 250 nm under ultrasound vibration
conditions. Nonetheless, Fe3O4 NPs and 99Tc-Fe3O4 NPs exhibited superparamagnetic properties, and the saturation magnetization values were about 55 and 47 emu/g, respectively.
The biodistribution showed that a portion of the 99mTc-Fe3O4 nanoparticles might embolize in a pulmonary capillary initially; the embolism radioactivity was cleared from the lungs and
was then taken up by the liver. 99mTc-Fe3O4 metabolized very slowly only 1–2% of the injected dose (ID) was excreted in urine and about 2.37% ID/g was retained in the
liver 4 h after injection. Radiopharmaceutically, 99mTc-Fe3O4 NPs displayed long-term retention, and only 99mTc-Fe3O4 NPs that dissociated to free pertechnetate could be excreted in urine. This research evaluated the feasibility of non-polymer
magnetic ferrite NPs labeled with technetium as potential radiopharmaceuticals in nuclear medicine.
Authors:Fang Wang, Lin Zhou, Jiahong Zhou, Xiaotian Gu, and Yuying Feng
Hypocrellins, natural photosensitizers including hypocrellin A (HA) and hypocrellin B (HB), have been used as a traditional
Chinese herbal medicine to cure various skin diseases. Hypocrellins have excellent antiviral activity, which can inhibit the
growth of human immunodeficiency virus. They also exhibit significant light-induced antitumor property. In this article, thermal
analysis technologies (e.g., differential scanning calorimetry and thermogravimetry) are employed to characterize whether the photosensitive hypocrellin
A could be encapsulated with silica nanoparticle (SN) material or not, and evaluate the stability of inclusion complex. The
results show that the inclusion complex exhibits improved performance in both stability and hydrophilicity than natural hypocrellin
A. Fluorescence spectrophotometry studies have also been performed to verify the thermal analysis results. The results suggest
that the thermal analysis technology could be used as an effective and rapid tool to characterize the encapsulation properties
of the novel anticancer HA–SN complex.
Authors:M. Iqbal, J. McLachlan, W. Jia, N. Braidy, G. Botton, and S. Eichhorn
Palladium nanoparticles (Pd-NPs) were prepared by a single-phase reduction of palladium acetate in the presence of different
organic thiol ligands. Sizes, size distributions and crystallinity of the Pd-NPs were determined by high resolution transmission
electron microscopy (HR-TEM) and powder X-ray diffraction (XRD) while thermogravimetric analysis coupled with mass spectroscopy
(TGA-MS) was employed to measure their organic ligand to palladium ratios and to quantify contaminants. No systematic effect
of the different ligands on the size and purity of the Pd-NPs was observed but 1st-generation Frechet dendron thiols had an about 4 times larger foot-print at the surface of the NPs than the other thiol ligands.
The size effect of silica nanoparticles (SiO2) on thermal decomposition of poly(methylmethacrylate) (PMMA) was investigated by the controlled rate thermogravimetry. Thermal
degradation temperature of PMMA–SiO2 composites depended on both fraction and size of SiO2, the thermal degradation temperature of 23 nm (diameter) SiO2–PMMA (6.1 wt%) was 13.5 °C higher than that of PMMA. The thermal stabilities of 17 nm SiO2–PMMA (3.2 wt%) and 13 nm SiO2–PMMA (4.8 wt%) were 21 and 23 °C, respectively, higher than that of PMMA without SiO2. The degree of degradation improvement was increased linearly with the surface area of SiO2. The number of surface hydroxyl group in unit volume of SiO2 particle increased with increasing the specific surface area of SiO2, and the interaction between hydroxide group of SiO2 and carbonyl group of PMMA had an important role to improve the thermal stability of PMMA.