Shema de realizare a proiectului 19 15 01 01 - Anul 2020 - Etapa II
Phase no. 60
Responsible: Dr. C. Viespe
Deadline: 9.12.2020
Title: "Realizarea si caracterizarea senzorilor pe baza de nanoparticule oxidice pentru detectia de compusi organici volatili"
Abstract: The research stage entitled “Fabrication and characterization of sensors based on oxidic nanoparticles for VOC detection” was completed, and all of its objectives were attained.
Oxidic nanoparticles (NP) of ZnO, TiO2 and WO3 were obtained by laser deposition using the same experimental conditions, in order to observe the way in which the nature of the material influences their characteristics. Targets of ZnO, TiO2 and WO3 were used, and the NPs were collected on membranes placed 35 mm away from the target. Scanning Electron Microscopy (SEM) was used to obtain information on the morphology of the NPs.
For all three oxides investigated, agglomerations of spherical NPs with various dimensions were obtained. The dimensions of ZnO NPs were between 10-20 nm, and that of the WO3 NPs between 10-30 nm. TiO2 morphology was different, in that we obtained particles with dimensions of about 1 µm, on the surface of which NPs with dimensions of 10-20 nm are visible.
The NPs were incorporated in turn into two types of polymers: polyethyleneimine (PEI) and polymethylsiloxane (PDMS), obtaining polymer-NP solutions with a concentration of 0.8 mg/ml. These solutions were deposited onto the quartz substrates by air-brush. The thickness of the films obtained was about 200 nm. Roughness measurements allowed us to observe that the presence of NPs leads to its reduction, due to the capacity of NPs to decrease the surface tension of the films and to thereby influence the wetting of the substrate.
The sensors thus obtained were tested for four types of VOCs (Volatile Organic Compounds): ethanol, toluene, acetone and dichloroethane. The presence of NPs leads to a considerable increase of the film sensitivity for all NP types. The sensors based on WO3 stood out as having the best sensitivity for the majority of the analytes, with an especially pronounced frequency shift in the case of acetone. In addition, we noticed that the sensors based on PEI led to frequency shifts about 10 times larger than those based on PDMS.
The objectives of the research stage were attained, and the basis for the next stage was created, namely the development of sensors based on nanoparticles for UV detection.
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Phase no. 61
Responsible: Dr. V. Craciun
Deadline: 9.12.2020
Title: "Modificarea structurii benzii interzise prin dopare /aliere cu alti oxizi metalici in filme subtiri depuse prin ablatie laser"
Abstract: In this project report, the structure and properties of Ag-doped ZnO films and SnO2 films were investigated. The results of the investigations showed that a concentration of up to 2% Ag does not induce essential changes in the crystalline structure of ZnO, the films growing textured along direction (002), as indicated by X-ray diffraction investigations and polar X-ray diffraction measurements. Also, investigations of specular and diffuse X-ray reflectivity at symmetrical or variable incidence angle (XRR and XRDS) confirmed that neither the mass density nor the surface roughness of the deposited films is altered by doping with Ag atoms. SnO2 films deposited for different durations using Ar or Ar containing 5% O2 were investigated using advanced nanometric resolution techniques. The results indicated that both the film thickness and the atmosphere used during deposition and the substrate temperature can affect the structure and optical properties of these films. Depending on the application, nanocrystalline films can be obtained, with crystalline grains of sizes of the order of 15-20 nm, with low values of the micro-stress and with variable band gap values, around 4 eV. Although X-ray diffraction investigations at the grazing incidence suggested the presence of other crystalline compounds such as Sn3O4 monoclinic in addition to the tetragonal SnO2 compound, X-ray photoelectron spectroscopy investigations indicated the presence of a single chemical compound. The value of the binding energies determined for O 1s and Sn 2p core-levels indicated only the presence of the compound SnO2 in the deposited films. Also, the use of an oxygen-containing atmosphere resulted in the incorporation of a small amount of oxygen into the crystal structure of the film, without affecting the films’ lattice parameters.
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Phase no. 62
Responsible: Dr. F. Dumitrache
Deadline: 9.12.2020
Title: "Diversificarea ariei de aplicatii teranostice sau antimicrobiene a caracteristicilor nanostructurilor magnetice pe baza de fier prin aditia de titan si siliciu"
Abstract: At this stage of research, parametric studies are being developed regarding the synthesis of iron oxide NPs doped or anchored with Si or Ti-based NPs. Samples of NPs with hybrid composition Si-Fe, hybrid iron oxide-silicon oxide, composite with iron oxide core and shell containing functional groups Si-O or Si-OH, iron oxide nanoparticles doped with Ti or mixed oxides of iron and titanium. Various tests have been performed, which must be continued in the area of synthesis of hybrid nanostructures with iron oxide and titanium oxide NPs. The synthesized nanoparticles were sometimes thermal treated or washed by the Soxlet technique for compositional purification. Nps are comprehensively analyzed by: FT-IR, EDS, XRD, TEM, SEM, BET. Wide ranges of NPs are reported in terms of both elemental composition, crystalline nanophases and meanparticle size. The doping with Si allowed the decrease of the particle size from values of 8-10 nm to particle sizes below 4 nm, dimensions that are circulating as being useful for SPION type NPs applications. Freshly synthesized or treated powders are subject to the preparation of stabilized or functionalized suspensions. A large range of poly-electrolytes is used, each suspension made in the aqueous medium has being analyzed by EDS and DLS to evaluate the degree of coverage and stability over time of the dispersed nanoaggregates. Thus, some recipes were performde regarding the preparation of stabilized suspensions of hybrid iron-silicon NPs , iron oxide with doping / decoration of Ti or Si with potential antimicrobial or antitumor antiviral activity. Based on the studies carried out and the finncial suport obtained within this NUCLEU project, 4 scientific articles are published in journals with a high ISI coefficient, two other articles being currently sent for publication.
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Phase no. 54b
Responsible: Dr. F. Sima
Deadline: 9.12.2020
Title: "Dispozitiv lab-on-a-chip cu dimensiuni nanometrice fabricat in sticla prin tehnologii laser substractive (partea II.1)"
Abstract: Micro- and nano-scale emerging technologies for biomaterial processing offer multiple possibilities to manufacture microfluidic devices with increased spatial resolution that allow testing biochemical reactions in nanoliter volumes. Herein we present our study of cancer cell migration through tridimensional micrometric channels of glass obtained by laser processing using picosecond (ps) laser pulses, picosecond laser-assisted etching - PLAE. We observed that the cells can migrate fast (approximately one hour) while the migration speed was found inverse proportional with channel volume. The envisaged applications of this device include personalized cancer therapy with a new tool for precision medicine. Specifically, biopsy samples could be analyzed by culturing cancer tumors harvested from patients in microfluidic biochips. The evaluation of cell population behavior could be correlated with the degree of migration and invasiveness at a single‐cell level. The objective in this type of therapeutic application is to test individual doses of radiation therapy, specific chemotherapy, immunotherapy, or a combination of a number of such therapies.
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Phase no. 64
Responsible: Dr. I. Paun
Deadline: 9.12.2020
Title: "Imprimare 4D de implanturi din nanocompozite magnetice pentru controlul comportamentului celular"
Abstract: 4-dimensional printing (4D printing) uses the same 3D printing techniques by computer-programmed deposition of material in successive layers to create a three-dimensional object. 4D printing adds the dimension of transformation over time, being a type of programmable material, in which after the manufacturing process, the printed product reacts with environmental parameters (in this case with static magnetic fields) and changes its functionality or shape accordingly. In this study, we demonstrate a proof of concept for magnetically-driven 2D cells organization on superparamagnetic micromagnets fabricated by laser direct writing via two photon polymerization (LDW via TPP) of a photopolymerizable superparamagnetic composite. The composite consisted of a commercially available, biocompatible photopolymer (Ormocore) mixed with 4 mg/mL superparamagnetic nanoparticles (MNPs). The micromagnets were designed in the shape of squares with 70 m lateral dimension. To minimize the role of topographical cues on the cellular attachment, we fabricated 2D microarrays similar with a chessboard: the superparamagnetic micromagnets alternated with non-magnetic areas of identical shape and lateral size as the micromagnets, made from Ormocore by LDW via TPP. The height difference between the superparamagnetic and non-magnetic areas was of about 6 m. In the absence of a static magnetic field, the fibroblasts attached uniformly on the entire 2D microarray, with no preference for the superparamagnetic or non-magnetic areas. Under a static magnetic field of 1.3T, the fibroblasts attached exclusively on the superparamagnetic micromagnets, resulting a precise 2D cell organization on the chessboard-like microarray. The described method has significant potential for fabricating biocompatible micromagnets with well-defined geometries for building skin grafts adapted for optimum tissue integration, starting from single cell manipulation up to the engineering of whole tissues and even organs.
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Phase no. 65
Responsible: Dr. B. Mihalcea
Deadline: 9.12.2020
Title: "Proiectarea și realizarea unui sistem electronic de alimentare al electrozilor unei capcane Paul destinată stocării de ioni (microparticule)."
Abstract: The aim of the research performed within the contract is to open new perspectives and validate novel experimental protocols on aerosol and nanoparticle diagnosis, with a special emphasis on the optical properties associated with them. The basic idea is to introduce new methods and tools for investigation and detailed characterization of the physico-chemical properties associated with these particles. The project aims to investigate microparticles and urban aerosol particles with an aim to characterize their optical properties in a combined approach, consisting of ground based measurements using electrody-namic (Paul) ion traps and mass spectrometry techniques. Microparticles (with dimensions ranging between 1 μm and 200 μm) can be trapped in vacuum or in air (under STP conditions), by means of three dimensional electrodynamic quadrupole fields and probed using laser fluorescence spectroscopy and Quadrupole Ion Trap - Mass Spectrometry (QIT-MS). Investigation of single particle emission spectra and of the associated optical resonance signatures by using the Lorenz-Mie theory supplies information regarding the particle size, shape, and its refractive index. The absolute mass and electric charge of single microspheres can be determined by measuring their secular oscillation frequencies in a Paul trap.
The expected results are: (a) design and test of new linear quadrupole and multipole ion trap geometries operating at Standard Ambient Temperature and Pressure conditions (SATP), optimized for aerosol and nanoparticle detection, that achieve a higher signal to noise ratio (SNR) and improved particle stability compared to current investigation methods; (b) realization of complex a.c. (0 ÷ 4 kV, 40 Hz ÷ 2 kHz) and d.c. (0 ÷ 1 kV) programmable electronic supplies, for trapping and diagnosis of microparticle and aerosol species, with integrated microcomputer boards; (c) new, refined methods for measuring the specific charge to mass ratio for different aerosol species based on ion trap mass spectrometry; (d) chemical and optical composition analysis investigations for the aerosol species of interest; (e) a future outcome of the project lies in the possibility to realize portable, ion trap based setups operating at SATP conditions, able to identify aerosols and polluting agents by measuring the specific charge to mass ratio.
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