Search results for " NANO"

On-chip purification of arc-discharge synthesized multiwalled carbon nanotubes via mobile liquid interface

2017

This thesis reports a novel approach for purification of carbon nanotube (CNT) samples deposited on smooth silicon substrates through a mobile liquid interface interacting with carbonaceous debris particles that contaminate the deposition. The method is based on physical interaction of the particles and the three-phase contact line via capillary interface forces, i.e. the surface tension, which results in the detachment of chemically indispersible colloids from the sample surface. In the experiments reported in this work, we focus primarily on arc-discharge grown multi-walled carbon nanotubes, whose synthesis is particularly plagued by carbonaceous debris that is difficult to remove without h…

Photocatalytic nano-composite architectural lime mortar for degradation of urban pollutants under solar and visible (interior) light

2017

Abstract Recent advances in nano-technology and nano-additives can give enhanced properties to natural hydraulic lime (NHL), creating a multifunctional material. We have prepared a novel nanocomposite, made of a commercial mortar with 1 wt% and 5 wt% added titania nanoparticles (NPs). These TiO 2 NPs are themselves doped with 1 mol% silver, to give the material enhanced photocatalytic and antimicrobial properties. The Ag-doped TiO 2 NPs were made from a simple, costs effective, aqueous green nanosynthesis process, and the end material only contains 0.01–0.05% Ag. As this mortar is intended to both combat atmospheric pollution, and create more durable/lower maintenance building facades (plas…

ytterbium nanoparticles: properties, recent synthesis, developments and prespectives

2011

Material science interest is more and more directed to the synthesis and characterization of nano-sized particles. This interest is justified by the fact that the reduction of the particle size of a given material to the nanometer scale causes the rising up of exotic properties that are not present in the bulk state due to size-dependent quantum effects and huge increase of the interfacial species. Further striking features can be gained by controlling nanoparticle shape or through the building up of spatially ordered mono-, bi- and three-dimensional nanoparticle arrays. Then, the wise selection of the nanoparticle synthetic strategy offers the possibility of preparing a wide class of novel…

Cadmium Metal–Organic Frameworks Based on Ditopic Triazamacrocyclic Linkers: Unusual Structural Features and Selective CO 2 Capture

2017

International audience; Two three-dimensional cadmium metal organic frameworks with general formula [Cd-2(L-1)(H2O)(3)](NO3)(0.7)(HCOO)(0.2)Br-0.1 (Cd2L1, L-1 = 1,4,7-tris(4-carboxybenzy1)-1,4,7-triazacyclononane) and Cd(HL2)(H2O)(2) (CdL2, L-2 = 1,4,7-tris(3-(4-benzoate)prop-2-yn-1-yl)-1,4,7-triazacydononane) based on 1,4,7-triazacyclononane N-functionalized by different arylcarboxylic acids were prepared under solvothermal conditions and characterized by single crystal X-ray analysis and porosity measurements. The crystal structure of Cd2L1 reveals a cationic net with a bcs topology,. and nodes are constituted by dinuclear cadmium complexes, in which each cadmium atom adopts a hexacoordin…

Biodegradable Metal-Organic Framework-Based Microrobots (MOFBOTs).

2020

Microrobots and metal–organic frameworks (MOFs) have been identified as promising carriers for drug delivery applications. While clinical applications of microrobots are limited by their low drug loading efficiencies and the poor degradability of the materials used for their fabrication, MOFs lack motility and targeted drug delivery capabilities. The combination of these two fields marks the beginning of a new era; MOF‐based small‐scale robots (MOFBOTs) for biomedical applications. Yet, biodegradability is a major hurdle in the field of micro‐ and nanoswimmers including small‐scale robots. Here, a highly integrated MOFBOT that is able to realize magnetic locomotion, drug delivery, and selec…

Statistical Approximation of Fourier Transform-IR Spectroscopy Data for Zinc White Pigment from Twentieth-Century Russian Paintings

2017

We present a statistical model for approximation of experimental Fourier transform-IR spectroscopy (FTIR) data for paint samples from paintings of different ages. The model utilizes random variations in some parameters (initial ageing rate, degree of change in ageing rate and time at which the change occurs). We determine the parameters characterizing variation in the paint composition and the storage conditions for the paintings. The numerical calculation is qualitatively consistent with the experimental data. In the proposed model, changes in the initial composition of the paint and the storage conditions make about the same contribution to the experimentally observed scatter in the data …

Jauna pieeja prostatas vēža cirkulējošu ekstracelulāro vezikulu selektīvai izolēšanai un to ietverto RNS biomarķieru analīze

2021

Audzēju producētās ekstracelulārās vezikulas (EVs) ir ieguvušas ievērojamu uzmanību zinātnieku vidū pēdējo gadu laikā, kā daudzsološs biomarķieru avots ar potenciālu pielietojumu vēža diagnostikā, prognostikā un monitorēšanā. Pacientu biofluīdos cirkulējošo EV izmantošanu šiem mērķiem apgrūtina tas, ka vēža izcelsmes EVs bieži sastāda zemu proporciju no kopējā parauga EV satura un šī proporcija mēdz atšķirties pacientu starpā. Tādēļ vajadzīgs meklēt jaunas pieejas, kas ļautu selektīvi izolēt un analizēt noteiktas EV subpopulācijas, kas bagātinātas ar vēža izcelsmes biomarķieriem. Adresējot šo aktualitāti, bakalaura darbā tika attīstīta un testēta jauna EV subpopulāciju izolēšanas metode – a…

EVALUATION OF BIODEGRADABILITY ON POLYSPARTAMIDE-POLYLACTIC ACID BASED NANOPARTICLES BY CHEMICAL HYDROLYSIS STUDIES POLYMER DEGRADATION AND STABILITY

2015

Here, the synthesis of two graft copolymers based on α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) and poly(lactic acid) (PLA), the O-(2-aminoethyl)-O′-galactosyl polyethylene glycol (GAL-PEG-NH2) or the methoxypolyethylene glycol amine (H2N-PEG-OCH3) is described. Starting from the obtained PHEA-PLA-PEG-GAL and PHEA-PLA-PEG copolymers, polymeric nanoparticles were prepared by high pressure homogenization–solvent evaporation method. To demonstrate their biodegradability as a function of the matrix composition, a chemical stability study was carried out until 21 days by incubating systems in two media mimicking physiological compartments (pH 7.4 and pH 5.5). The degradability of both nan…

Evaluation of biodegradability of novel polymeric nanoparticles based on amphiphilic polylactide-polyaspartamide derivatives.

2015

Photoluminescence properties of S2 molecule trapped in Melanophlogite

2015

We studied the photoluminescence properties of a sample of SiO2-clathrate Melanophlogite, a crystalline microporous material which is found in nature as a rare mineral. Upon β irradiation, the material displays an intense light emission under near-UV illumination. We studied in detail this optical activity by steady-state and time-resolved photoluminescence measurements as a function of temperature. The spectroscopic properties we find can be ascribed to a population of quasi-free molecules trapped within each of the two different types of cage available in the structure of this clathrate, although the spectroscopic properties of the guest molecules are affected by their interactions with t…