Different Kinds Of Nanoparticles Research Articles

H2O based different nanofluids with unsteady condition and an external magnetic field on permeable channel heat transfer

This paper investigates numerically the problem of unsteady magnetohydrodynamic nanofluid flow and heat transfer between parallel plates due to the normal motion of the porous upper plate. The governing equations are solved via the fourth-order Runge-Kutta method. Different kind of nanoparticles is examined. The effects of kind of nanoparticle, nanofluid volume fraction, expansion ratio, Hartmann number, Reynolds number on velocity and temperature profiles are considered. Also effect of different types of nanoparticles is examined. Results indicate that velocity decreases with increase of Hartmann number due to effect of Lorentz forces. Rate of heat transfer increase with increase of nanofluid volume fraction, Hartmann number and Reynolds number but it decreases with increase of expansion ratio. Also it can be found that choosing copper as a nanoparticle leads to highest enhancement.

Nanocomposites of Polymeric Biomaterials Containing Carbonate Groups: An Overview

The modification of biomaterials using nanoadditives can lead to the development of novel materials for a wide variety of biomedical applications such as drug administration systems, tissue engineering, bioresistance coatings, and biomedical instruments. Moreover, a further improvement of mechanical and thermal properties of aforementioned biomaterials while maintaining their dimensional stability is a goal of major scientific researches. Aliphatic polycarbonates (APCs) containing carbonate groups such as poly(trimethylene carbonate), poly(propylene carbonate), poly(ethylene carbonate), poly(dimethyl trimethylene carbonate), etc., have become much more interesting compared to other biodegradable materials due to their unique physical and chemical properties. This review presents the effect of applying different kinds of nanoparticles (NPs) on the mechanical, thermal, and viscoelastic properties as well as dimensional stability and biocompatibility of APCs. The dispersion process of nanofillers within polymer matrices has been divided into two groups, solution and melt mixing techniques. Moreover, synthesis procedures of APC loaded NPs for drug delivery systems and electrospinning of nanofiber mats have also been reviewed. In order to clarify the effect of NPs on the overall characteristics of the APC biomaterials, the detailed mechanism of improving process have been extensively discussed.

Nanoparticles as Theranostic Vehicles in Experimental and Clinical Applications-Focus on Prostate and Breast Cancer.

Prostate and breast cancer are the second most and most commonly diagnosed cancer in men and women worldwide, respectively. The American Cancer Society estimates that during 2016 in the USA around 430,000 individuals were diagnosed with one of these two types of cancers, and approximately 15% of them will die from the disease. In Europe, the rate of incidences and deaths are similar to those in the USA. Several different more or less successful diagnostic and therapeutic approaches have been developed and evaluated in order to tackle this issue and thereby decrease the death rates. By using nanoparticles as vehicles carrying both diagnostic and therapeutic molecular entities, individualized targeted theranostic nanomedicine has emerged as a promising option to increase the sensitivity and the specificity during diagnosis, as well as the likelihood of survival or prolonged survival after therapy. This article presents and discusses important and promising different kinds of nanoparticles, as well as imaging and therapy options, suitable for theranostic applications. The presentation of different nanoparticles and theranostic applications is quite general, but there is a special focus on prostate cancer. Some references and aspects regarding breast cancer are however also presented and discussed. Finally, the prostate cancer case is presented in more detail regarding diagnosis, staging, recurrence, metastases, and treatment options available today, followed by possible ways to move forward applying theranostics for both prostate and breast cancer based on promising experiments performed until today.

Thermal Properties and Solar Collection Characteristics of Oil-based Nanofluids with Low Graphene Concentration

Abstract In order to improve properties of the photothermal conversion of heat-transfer oil used for direct absorption solar collection, a small amount of graphene was added to the base oil. The dispersion stability, thermal conductivity, and kinetic viscosity of oil-based nanofluids with different mass fraction of graphene were experimentally measured and analyzed. The dispersion stability was obtained using microscope imaging system, thermal conductivity was measured by a KD2 Pro thermal conductivity analyser, and kinetic viscosity was determined by viscometer. In addition, the absorption characteristics of graphene/oil nanofluids with different kinds of nanoparticles were tested by spectrophotometer. Finally, the experiment of nanofluid-based direct absorption solar collector (NDASC) was carried out and analyzed. Results show that the thermal conductivity of nanofluids was improved significantly and the kinetic viscosity of nanofluids reduced compared with that of pure oil; the optical characteristics of Oil-based graphene nanofluids presented high absorption coefficient, high extinction coefficient, and low scattering coefficient; The addition of nanoparticles to pure heat transfer oil could obviously enhance heat collection efficiency, and graphene/oil nanofluids obtained highest heat collection efficiency compared with CuO/oil nanofluids and graphite/oil nanofluids, which verified its feasibility and superiority of oil-based graphene nanofluids applied to direct absorption solar collector (DASC).

Continuous separation of nanoparticles by type via localized DC-dielectrophoresis using asymmetric nano-orifice in pressure-driven flow

This paper presents a nano-orifice based microfluidic device using a direct current dielectrophoresis (DC-DEP) method to continuously separate different types of micro and nanoparticles of similar sizes by their different electric conductivities in pressure-driven flow. The DC-DEP force is generated by applying a low electric potential difference via a small nano-size orifice on one side wall of the channel and a micron size orifice on the opposite wall. The particles will experience the DEP forces when passing through the vicinity of the small orifice where the strongest non-uniform electric field exists. Experiments were conducted by adjusting the electric conductivity of the suspending medium so that one kind of particles will experience positive DEP force while another experiences negative DEP. In this way, the separation of 140nm polystyrene (PS) and 150nm magnetic nanoparticles and the separation of 470nm magnetic-coated PS and 490nm PS nanoparticles were demonstrated, and the separation of 5.2μm magnetic-coated PS and 7μm PS particles and the separation of 14μm sliver-coated hollow glass beads and 15μm PS particles were also conducted. In comparison with the reported DC-DEP methods which are commonly used to separate microparticles by size and the alternative current DEP (AC-DEP) techniques which can separate different types of microparticles by applying high frequency alternating current with inserted microelectrodes, this method uses a pair of asymmetrical orifices on the opposite sides of channel walls to induce strong non-uniformity of electrical field and is capable of separating different kinds of nanoparticles. Furthermore, this method involves relatively low electric potential applied locally and hence the Joule heating effect and the electrochemical reaction at the electrodes are minimized.

Various Morphologies/Phases of Gold-Based Nanocomposite Particles Produced by Pulsed Laser Irradiation in Liquid Media: Insight in Physical Processes Involved in Particles Formation

In this work taking Au/MxOy (M = Fe, Co, Ni) particles as examples, we investigate and discuss the physical processes involved in particles formation by laser irradiation of mixture of two different kinds of nanoparticles dispersed in liquids. We showed that this method is an efficient and universal way for synthesis and control a variety of composite particles with various morphology (core–shell, alloy) and compositions which are not only metals or oxides but also nonequilibrium bimetallic alloys (AuFe, AuCo, and AuNi). Additionally, fluence diagrams which were designed to show the relation between laser fluence and particle diameter plot based on the heating–melting–evaporation model are useful for better understanding of the mechanism of composite particles formation during pulsed laser irradiation. To the extent of our knowledge, this is the first explanation of the mechanism of Au-based composite particles formation during pulsed laser irradiation of mixture of two different raw nanomaterials dispers...

Fracture toughness (Mode I) characterization of SiO 2 nanoparticle filled basalt/epoxy filament wound composite ring with split-disk test method

Abstract Matrix cracking which is the major initial form of damage in fiber reinforced polymer composites plays significant role in determining the fracture toughness. The fast crack propagation in polymer matrix causes to decrease the fracture toughness of fiber reinforced polymer (FRP) composite. In order to retard the fast crack propagation in polymer matrix and provide to increase of the fracture toughness of FRP composite, the polymer matrix of FRP composite is modified by filling the different kinds of nanoparticles. In such a way, the crack propagation leads to retard and dissipate the stress concentration affected to form the fiber cracks along of fibers in composite structure. In this study, basalt fiber was used as reinforcement material in ±[55]6 filament wound ring composite for creating the alternative to carbon, kevlar and glass fibers, to contribute to the research studies and literature. SiO2 nanoparticles that provides to form the effects of fracture toughness mechanism based on the effect of retarding crack propagation were filled into epoxy matrix to increase the mechanical properties and fracture toughness of ±[55]6 filament wound BFR/Epoxy ring composite. The split-disk tensile tests of single edge notched and un-notched ±[55]6 filament wound BFR/Epoxy ring composite specimens were conducted to determine the mechanical properties and mode I fracture toughness. SiO2 nanoparticle addition into epoxy matrix of ±[55]6 filament wound BFR/Epoxy ring composites has given the results of hoop tensile stress within the range of 27.7–30.3%. The fracture toughness of composite ring specimen was specified by ASTM E 399-12E3 by adapting to the directed mode I crack propagation and compared with each other. An effective increase in mode I fracture toughness of 43%–50% was obtained at 4 wt% addition level of SiO2 nanoparticles. The crack branching in epoxy matrix provided by SiO2 nanoparticle, matrix cracking, debonding, delamination and fiber breakage failures has been observed via microscope and SEM analysis.

Magnetohydrodynamic Heat Transfer of Nanofluids Past a Stretching Cylinder with Non-Uniform Heat Source/Sink and Chemical Reaction

In this investigation, we intend to present the magnetohydrodynamic (MHD) heat and mass transfer of nanofluids along a stretching cylinder in the presence of non-uniform heat source/sink and chemical reaction under the prescribed surface heat flux boundary conditions on the cylinder surface. The governing partial differential equations are approximated by a system of non-linear locally similarity ordinary differential equations which are solved numerically using fifth-order Runge–Kutta–Fehlberg (RKF45) integration scheme shooting method. Present results are compared with the previously published results in some limiting cases and the results are found to be in an excellent agreement. Three different kinds of nanoparticles, namely copper (Cu), alumina (\({\hbox {Al}}_2{\hbox {O}}_3\)) and titanium dioxide (\({\hbox {TiO}}_2\)) with water as base fluid are considered here. The numerical results for the dimensionless velocity, temperature and nanoparticle volume fraction as well as on local skin-friction coefficient, local Nusselt number and Sherwood number have been constructed and illustrated graphically to reveal some interesting physical phenomena. The results of the present paper show that the flow velocity and temperature on the stretching cylinder and also skin-friction coefficient are strongly influenced by the curvature parameter.

In Vitro Cytotoxicity of Maxillofacial Silicone Elastomers: Effect of Nano-particles.

Silicone elastomers are generally used for maxillofacial extraoral prostheses. The purpose of this in vitro study was to evaluate the cytotoxicity of different kinds of nanoparticles added to two types of maxillofacial elastomers. A-2000 and A-2006 silicone elastomers were used. The silicone specimens were divided into eight groups according to the presence of additional nanoparticles (n = 18). The following represents the groups in the study: Group A: A-2000 silicone (control group); Group B: A-2006 silicone (control group); Group C: A-2000 silicone and the addition of titanium dioxide (TiO2 ); Group D: A-2006 silicone and the addition of TiO2 ; Group E: A-2000 silicone and the addition of fumed silica; Group F: A-2006 silicone and the addition of fumed silica; Group G: A-2000 silicone and the addition of silaned silica; Group H: A-2006 silicone and the addition of silaned silica. A paired sample t-test was used to analyze the cytotoxicity of each group after 24, 48, and 72 hours. Based on the results of the 24-hour analysis, the biocompatibility values of the (A-2006) fumed silica group were higher than those of the control groups. There was no statistically significant difference in A-2006 and A-2000 groups. The cytotoxicity values of the control groups and TiO2 (A-2000 silicone) elastomer groups increased at all test times; however, the cytotoxicity values of the TiO2 (A-2006), fumed silica (A-2006), silaned silica (A-2006), fumed silica (A-2000), and silaned silica (A-2000) groups increased significantly only from 24 to 48 hours. Nanoparticles of TiO2 , fumed silica, and silaned silica added to a commercial silicone-based elastomer used for fabrication of maxillofacial prostheses are nontoxic.

Impact of counterpart materials and nanoparticles on the transfer film structures of polyimide composites

The nanostructures of the transfer films of polyimide (PI) composites generated when slid against various metallic counterparts including standard bearing steel, electroplated chromium coating (Cr), and stainless steel were comprehensively investigated. Moreover, the effect of h-BN and amorphous SiO2 nanoparticles on the transfer film structures of the conventional composite filled with short carbon fibers and graphite were studied. It was identified that the composition of the counterparts and nanoparticles' structure exert important effects on transfer film formation. When the conventional composite rubs with the steel counterparts, obvious tribo-oxidation occurs and therefore retards material transfer. However, the composite shows a much improved tribological performance when slides against Cr due to formation of a carbonaceous transfer film. Both kinds of nanoparticles significantly mitigate tribo-oxidation and greatly enhance the tribological performance. Nevertheless, the two different kinds of nanoparticles lead to distinct transfer film structures. High resolution transmission electron microscopy analyses of transfer films reveal that tribo-sintering of nano-SiO2 occurs, whereas h-BN particles are crushed and uniformly mixed with wear products. Moreover, h-BN transforms to c-BN probably owing to the high temperature and stress on the rubbing interface. This work can provide guidance for the formulation of best matching composites according to metallic counterparts.

Coupling Microbial Growth with Nanoparticles: A Universal Strategy To Produce Functional Fungal Hyphae Macrospheres.

Macroscale assembly of nanoscale building blocks is an intriguing way to translate the unique characteristics of individual nanoparticles into macroscopic materials. However, the lack of the efficient universal assembly strategy seriously hinders the possibility of macroscale architectures in practical applications. Herein, we develop a general, environment-friendly, and scalable microbial growth method for the construction of macroscopic composite assemblies with excellent mechanical strength by in situ integrating various types of nanoparticles into fungal hyphae (FH) macrospheres. Notably, the size of the FH-based composite spheres and the loading amount of the nanoparticles with different dimensions can be well tuned by controlling the cultivation time and the dosage of nanoparticles, respectively. Interestingly, bifunctional FH-based core-shell macrospheres can also be achieved by programmed assembling two different kinds of nanoparticles in the cultivation process. The produced multifunctional FH-based composite spheres exhibit wide potential applications in magnetic actuation, photothermal therapy, and contaminant adsorption, etc.

Coupling of a single active nanoparticle to a polymer-based photonic structure

Abstract The engineered coupling between a guest moiety (molecule, nanoparticle) and the host photonic nanostructure may provide a great enhancement of the guest optical response, leading to many attractive applications. In this article, we describe briefly the basic concept and some recent progress considering the coupling of a single nanoparticle into a photonic structure. Different kinds of nanoparticles of great interest including quantum dots and nitrogen-vacancy centers in nanodiamond for single photon source, nonlinear nanoparticles for efficient nonlinear effect and sensors, magnetic nanoparticles for Kerr magneto-optical effect, and plasmonic nanoparticles for ultrafast optical switching and sensors, are briefly reviewed. We focus further on the coupling of plasmonic gold nanoparticles and polymeric photonic structures by optimizing theoretically the photonic structures and developing efficient way to realize desired hybrid structures. The simple and low-cost fabrication technique, the optical enhancement of the fluorescent nanoparticles induced by the photonic structure, as well as the limitations, challenges and appealing prospects are discussed in details.

Nanoclay migration from food packaging materials

ABSTRACTA recent trend is to use nanocomposites materials for food-packaging applications. Different kinds of nanoparticles are incorporated into the polymers to improve their characteristics, and, among them, nanoclay is used to improve their barrier properties to gases. In this work, the results of migration studies with different food simulants (ethanol 10% and acetic acid 3%), temperatures and times (40ºC for 10 days and 70ºC for 2 h) from two commercialised LDPE nanocomposite bags are presented. The migration solutions thus obtained were analysed by ICP-MS to evaluate the amount of aluminium which migrated into the solutions both in dissolved form and as a part of nanoparticles. Aluminium migration was observed for both samples with a maximum migration value of 51.65 ng cm–2 for the Aisaika bags and 24.14 ng cm–2 for the Debbie Meyer bags. The presence of spikes working in single-particle mode using ICP-MS indicated that part of this aluminium was present as nanoparticles. The size and morphology of the nanoclay, in both the original material and the migration solutions, was studied by scanning electron microscopy coupled to energy-dispersive X-ray diffraction (SEM-EDX). In this manner, nanoparticles of different morphologies and sizes were found to migrate into the food simulants.

Superhydrophobic fluorine-free hierarchical coatings produced by vacuum based method

In this study it is presented fully vacuum-based, substrate independent method for fabrication of fluorine-free superhydrophobic surfaces based on combination of gas aggregation sources of nanoparticles and plasma polymerization. This method involves deposition of films of nanoparticles that are subsequently overcoated by plasma polymerized n-hexane. Two different kinds of nanoparticles that differ significantly in their sizes were used: small Cu nanoparticles (mean diameter 18nm) and big plasma polymerized C:H nanoparticles (diameter 110nm). It is demonstrated that superhydrophobic and slippery character may be achieved when surfaces with dual-scale roughness were prepared combining bigger C:H nanoparticles with smaller Cu nanoparticles.

Microscopies at the Nanoscale for Nano-Scale Drug Delivery Systems

One of the frontier of nanoscience is undoubtedly represented by the use of nanotechnologies in the pharmaceutical research. During the last decades a big family of nanostructures that have a surface-acting action, such as NanoParticles (NPs), lipid nanocarriers and many more, have been developed to be used as Drug Delivery Systems (DDSs). However, these nanocarriers opened also new frontiers in nanometrology, requiring an accurate morphological characterization, near atomic resolution, before they are really available to clinicians to ascertain their elemental composition, to exclude the presence of contaminants introduced during the synthesis procedure and to ensure biocompatibility. Classical Transmission (TEM) and Scanning Electron Microscopy (SEM) techniques frequently have to be adapted for an accurate analysis of formulation morphology, especially in case of hydrated colloidal systems. Specific techniques such as environmental scanning microscopy and/or cryo preparation are required for their investigation. Analytical Electron Microscopy (AEM) techniques such as Electron Energy-Loss Spectroscopy (EELS) or Energy-Dispersive X-ray Spectroscopy (EDXS) are additional assets to determine the elemental composition of the systems. Here we will discuss the importance of Electron Microscopy (EM) as a reliable tool in the pharmaceutical research of the 21(st) century, focalizing our attention on advantages and limitations of different kind of NPs (in particular silver and carbon NPs, cubosomes) and vesicles (liposomes and niosomes).

Exploiting Bacterial Pathways for BBB Crossing with PLGA Nanoparticles Modified with a Mutated Form of Diphtheria Toxin (CRM197): In Vivo Experiments.

Drugs can be targeted to the brain using polymeric nanoparticles (NPs) engineered on their surface with ligands able to allow crossing of the blood-brain barrier (BBB). This article aims to investigate the BBB crossing efficiency of polymeric poly lactide-co-glycolide (PLGA) NPs modified with a mutated form of diphtheria toxin (CRM197) in comparison with the results previously obtained using PLGA NPs modified with a glycopeptide (g7-NPs). Different kinds of NPs, covalently coupled PLGA with different fluorescent probes (DY405, rhodamine-B base and DY675) and different ligands (g7 and CRM197) were tested in vivo to assess their behavior and trafficking. The results highlighted the possibility to distinguish the different kinds of simultaneously administered NPs and to emphasize that CRM-197 modified NPs and g7-NPs can cross the BBB at a similar extent. The analysis of BBB crossing and of the neuronal tropism of CRM197 modified NPs, along with their BBB crossing pathways were also developed. In vivo pharmacological studies performed on CRM197 engineered NPs, loaded with loperamide, underlined their ability as drug carriers to the CNS.

Membrane-based lateral flow immunochromatographic strip with nanoparticles as reporters for detection: A review.

Membrane-based lateral flow immunochromatographic strip (LFICS) is widely used in various fields because of its simplicity, rapidity (detection within 10min), and low cost. However, early designs of membrane-based LFICS for preliminary screening only provide qualitative ("yes/no" signal) or semi-quantitative results without quantitative information. These designs often suffer from low-signal intensity and poor sensitivity and are only capable of single analyte detection, not simultaneous multiple detections. The performance of existing techniques used for detection using LFICS has been considerably improved by incorporating different kinds of nanoparticles (NPs) as reporters. NPs can serve as alternative labels and improve analytical sensitivity or limit of detection of LFICS because of their unique properties, such as optical absorption, fluorescence spectra, and magnetic properties. The controlled manipulation of NPs allows simultaneous or multiple detections by using membrane-based LFICS. In this review, we discuss how colored (e.g., colloidal gold, carbon, and colloidal selenium NPs), luminescent (e.g., quantum dots, up-converting phosphor NPs, and dye-doped NPs), and magnetic NPs are integrated into membrane-based LFICS for the detection of target analytes. Gold NPs are also featured because of their wide applications. Different types and unique properties of NPs are briefly explained. This review focuses on examples of NP-based LFICS to illustrate novel concepts in various devices with potential applications as screening tools. This review also highlights the superiority of NP-based approaches over existing conventional strategies for clinical analysis, food safety, and environmental monitoring. This paper is concluded by a short section on future research trends regarding NP-based LFICS.

Antimicrobial photodynamic inactivation in nanomedicine: small light strides against bad bugs.

The relentless advance of drug-resistance among pathogenic microbes, mandates a search for alternative approaches that will not cause resistance. Photodynamic inactivation (PDI) involves the combination of nontoxic dyes with harmless visible light to produce reactive oxygen species that can selectively kill microbial cells. PDI can be broad-spectrum in nature and can also destroy microbial cells in biofilms. Many different kinds of nanoparticles have been studied to potentiate antimicrobial PDI by improving photosensitizer solubility, photochemistry, photophysics and targeting. This review will cover photocatalytic disinfection with titania nanoparticles, carbon nanomaterials (fullerenes, carbon nanotubes and graphene), liposomes and polymeric nanoparticles. Natural polymers (chitosan and cellulose), gold and silver plasmonic nanoparticles, mesoporous silica, magnetic and upconverting nanoparticles have all been used for PDI.

Applications and limitations of lipid nanoparticles in dermal and transdermal drug delivery via the follicular route

Lipid nanoparticles (LN) such as solid lipid nanoparticles (SLN) and nanolipid carriers (NLC) feature several claimed benefits for topical drug therapy including biocompatible ingredients, drug release modification, adhesion to the skin, and film formation with subsequent hydration of the superficial skin layers. However, penetration and permeation into and across deeper skin layers are restricted due to the barrier function of the stratum corneum (SC). As different kinds of nanoparticles provide the potential for penetration into hair follicles (HF) LN are applicable drug delivery systems (DDS) for this route in order to enhance the dermal and transdermal bioavailability of active pharmaceutical ingredients (API). Therefore, this review addresses the HF as application site, published formulations of LN which showed follicular penetration (FP), and characterization methods in order to identify and quantify the accumulation of API delivered by the LN in the HF. Since LN are based on lipids that appear in human sebum which is the predominant medium in HF an increased localization of the colloidal carriers as well as a promoted drug release may be assumed. Therefore, sebum-like lipid material and a size of less or equal 640nm are appropriate specifications for FP of particulate formulations.

Influence of Cu, TiO<SUB>2</SUB> Nanoparticles and Carbon Nano-Horns on Tribological Properties of Engine Oil

The addition of nanoparticles in lubricating oils recently demonstrated to reduce the coefficient of friction and to increase the load-carrying capability of lubricant in coupled surfaces. In this work, different kinds of nanoparticles were tested as additives to engine oil to improve lubrication: copper and titanium oxide nanoparticles and single walled carbon nanohorns (SWCNHs). Two nanoparticle sizes were also tested in case of copper. The tribological properties of these nanofluids were evaluated by Stribeck tests, in order to compare the effect of nanoparticles on friction coefficient and electric contact resistance in different lubrication regimes. Stribeck curves showed that the coefficient of friction was reduced, compared to raw oil, by the action of Cu nanoparticles having 130 nm diameter, leading to a mean decrease of about 17%, and by SWCNHs, with a mean decrease of about 12%. Conversely, no significant changes were detected in presence of Cu nanoparticles having 50 nm diameter or of TiO2. The suspension viscosity and stability were also tested. Wear tests were also carried out, showing a reduction of wear rate up to nearly 50% for Cu nanoparticles (150 nm diameter) and around 30% for SWCNHs. The measurements showed that nanoparticles having size comparable to the mean roughness of coupled surfaces significantly improved the tribological properties of bare oil. An explanation of nanoparticle action is proposed.