scholarly journals Single-step synthesis of three-dimensional particles using non-uniform UV polymerization

2021 ◽  
Author(s):  
Navid Hakimi
Keyword(s):  
Uv Light ◽  
Three Dimensional ◽  
Microfluidic Channel ◽  
Precursor Solution ◽  
Monomer Conversion ◽  
Single Step ◽  
Shape Dependence ◽  
Straightforward Method ◽  
One Step ◽  
Stop Flow

Polymer-based microparticles are increasingly utilized in a range of biotechnology application. There is growing evidence that microparticle shape is an important parameter governing its functionality. Yet, there currently exists no straightforward method to controllably synthesize a large number of highly three-dimensional (3D) microparticles. In this thesis, we develop a one-step two-dimensional (2D) stop-flow lithography method that exploits the non-uniformity of the polymerizing ultraviolet (UV) light, UV adsorption by opaque nanoparticles in the precursor solution, and discontinuous photomask patterns, to make highly curved 3D microparticles. We investigate the microparticle shape dependence on each parameter by independently tuning the field and focus of the UV light, adding opaque magnetic nanoparticles to the precursor solution, and using a variety of photomask patterns.We also perform numerical simulations of oxygen concentration and monomer conversion in the microfluidic channel, to predict the particle shape. By simplifying the synthesis of high curvature 3D particles with 3D surface features and branched structures, our method may lead to the expanded use of microparticles in research and in industry.

scholarly journals Single-step synthesis of three-dimensional particles using non-uniform UV polymerization

2021 ◽  
Author(s):  
Navid Hakimi
Keyword(s):  
Uv Light ◽  
Three Dimensional ◽  
Microfluidic Channel ◽  
Precursor Solution ◽  
Monomer Conversion ◽  
Single Step ◽  
Shape Dependence ◽  
Straightforward Method ◽  
One Step ◽  
Stop Flow

Polymer-based microparticles are increasingly utilized in a range of biotechnology application. There is growing evidence that microparticle shape is an important parameter governing its functionality. Yet, there currently exists no straightforward method to controllably synthesize a large number of highly three-dimensional (3D) microparticles. In this thesis, we develop a one-step two-dimensional (2D) stop-flow lithography method that exploits the non-uniformity of the polymerizing ultraviolet (UV) light, UV adsorption by opaque nanoparticles in the precursor solution, and discontinuous photomask patterns, to make highly curved 3D microparticles. We investigate the microparticle shape dependence on each parameter by independently tuning the field and focus of the UV light, adding opaque magnetic nanoparticles to the precursor solution, and using a variety of photomask patterns.We also perform numerical simulations of oxygen concentration and monomer conversion in the microfluidic channel, to predict the particle shape. By simplifying the synthesis of high curvature 3D particles with 3D surface features and branched structures, our method may lead to the expanded use of microparticles in research and in industry.

Single step synthesized three dimensional spindle-like nanoclusters as lithium-ion battery anodes

CrystEngComm ◽  
2018 ◽  
Vol 20 (22) ◽  
pp. 3043-3048 ◽  
Author(s):  
Lingyu Zhang ◽  
Zhigang Gao ◽  
Haiming Xie ◽  
Chungang Wang ◽  
Lu Li ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Lithium Ion Battery ◽  
Anode Materials ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Single Step ◽  
Conventional Heating ◽  
Heating Method ◽  
3D Architecture ◽  
One Step

A facile, green, mild and one-step conventional heating method was developed to synthesize monodisperse Sn-doped Fe2O3 nanoclusters with a novel spindle-like 3D architecture as anode materials for lithium-ion batteries.

Fabrication of suspended, three-dimensional chiral plasmonic nanostructures with single-step electron-beam lithography

RSC Advances ◽  
2015 ◽  
Vol 5 (117) ◽  
pp. 96366-96371 ◽  
Author(s):  
Eunice Sok Ping Leong ◽  
Jie Deng ◽  
Eng Huat Khoo ◽  
Siji Wu ◽  
Wee Kee Phua ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electron Beam Lithography ◽  
Three Dimensional ◽  
Single Step ◽  
Plasmonic Nanostructures ◽  
Plasmonic Nanostructure ◽  
One Step

Suspended 3D chiral plasmonic nanostructure fabricated with only one-step electron-beam lithography.

scholarly journals Three-dimensional closed microfluidic channel fabrication by stepper projection single step lithography: the diabolo effect

Lab on a Chip ◽  
2012 ◽  
Vol 12 (2) ◽  
pp. 387-390 ◽  
Author(s):  
F. Larramendy ◽  
L. Mazenq ◽  
P. Temple-Boyer ◽  
L. Nicu
Keyword(s):  
Three Dimensional ◽  
Microfluidic Channel ◽  
Single Step

Controllable Electrochemical Synthesis of Ag Hierarchical Micro/Nanostructures with High SERS-Activity

NANO ◽  
2020 ◽  
Vol 15 (04) ◽  
pp. 2050043
Author(s):  
Huayu Zhou ◽  
Jingjing Wang ◽  
Qiong Yang ◽  
Menglei Chen ◽  
Changsheng Song ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Current System ◽  
Three Dimensional ◽  
Constant Current ◽  
Localized Surface Plasmon ◽  
Excitation Wavelength ◽  
Raman Signal ◽  
Mixed Solution ◽  
Raman Enhancement ◽  
One Step

We report a one-step electrochemical deposition technique to prepare three-dimensional (3D) Ag hierarchical micro/nanostructured film consisting of well-crystallized Ag nanosheets grown on an indium tin oxide (ITO) conductive substrate. The Ag hierarchical micro/nanostructures were fabricated in the mixed solution of AgNO3 and sodium citrate in a constant current system at room temperature. Through reduction of Ag[Formula: see text] electrodeposited on the surface of ITO substrate, nanoparticles were grown to form nanosheets which further combined into 3D sphere-like microstructures. The 3D Ag micro/nanostructures have many sharp edges and nanoscale gaps which can give rise to good Raman-enhanced effect. Due to localized surface plasmon resonance (LSPR) effects, these special Ag micro/nanostructures exhibited good Raman-enhanced performance. Using Rhodamine 6G (R6G) molecules as probe molecule, we studied the influence of excitation wavelength on Raman enhancement. The results showed that the 532[Formula: see text]nm excitation wavelength is the best to obtain the strongest Raman signal and to reduce the influence of other impurity peaks. Using the as-synthesized Ag hierarchical micro/nanostructures, we can detect the 10[Formula: see text][Formula: see text]mol/L R6G aqueous solution, exhibiting great Raman-enhanced effect.

Synthesis of Polycycles and Oxacycles by Tandem Metathesis of endo–norbornene Derivatives

Synthesis ◽  
2021 ◽  
Author(s):  
Sambasivarao Kotha ◽  
Sunil Pulletikurti ◽  
Ambareen Fatma ◽  
gopal dhangar ◽  
gonna somu Naidu
Keyword(s):  
Natural Products ◽  
Metal Complex ◽  
Carbonyl Group ◽  
Single Step ◽  
Time Dependent ◽  
Computational Studies ◽  
Nmr Studies ◽  
Tricyclic Compounds ◽  
One Step ◽  
Norbornene Derivatives

Here, we have demonstrated that the presence of a carbonyl group at C7 position is preventing the olefin metathesis of endo-norbornene derivatives due to the complexation of the metal alkylidene. Time-dependent NMR studies showed the presence of new proton signals in the metal alkylidene region, which indicate the formation of metal complex with the carbonyl group of the substrate. These observations were further proved by ESI-MS analysis. Whereas, computational studies provided that the catalyst was interacting with the C7 carbonyl group and aligned perpendicular to that of norbornene olefin. Later, these endo-keto norbornene derivatives were reduced to hydroxyl derivatives diastereoselectively. Ring-rearrangement metathesis (RRM) of these hydroxyl derivatives, produced the [6/5/6], and [5/6/5] carbo-tricyclic cores of the natural products in one step. Whereas the RRM of O-allyl derivatives, delivered the oxa-tricyclic compounds in a single step with excellent yields.

scholarly journals A Review on Additive Manufacturing Possibilities for Electrical Machines

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1940
Author(s):  
Muhammad Usman Naseer ◽  
Ants Kallaste ◽  
Bilal Asad ◽  
Toomas Vaimann ◽  
Anton Rassõlkin
Keyword(s):  
Additive Manufacturing ◽  
Large Scale ◽  
Three Dimensional ◽  
Electrical Machines ◽  
Electromagnetic Properties ◽  
Scale Production ◽  
Performance Parameters ◽  
Large Scale Production ◽  
One Step ◽  
Manufacturing Techniques

This paper presents current research trends and prospects of utilizing additive manufacturing (AM) techniques to manufacture electrical machines. Modern-day machine applications require extraordinary performance parameters such as high power-density, integrated functionalities, improved thermal, mechanical & electromagnetic properties. AM offers a higher degree of design flexibility to achieve these performance parameters, which is impossible to realize through conventional manufacturing techniques. AM has a lot to offer in every aspect of machine fabrication, such that from size/weight reduction to the realization of complex geometric designs. However, some practical limitations of existing AM techniques restrict their utilization in large scale production industry. The introduction of three-dimensional asymmetry in machine design is an aspect that can be exploited most with the prevalent level of research in AM. In order to take one step further towards the enablement of large-scale production of AM-built electrical machines, this paper also discusses some machine types which can best utilize existing developments in the field of AM.

scholarly journals Is Dialdehyde Chitosan a Good Substance to Modify Physicochemical Properties of Biopolymeric Materials?

2021 ◽  
Vol 22 (7) ◽  
pp. 3391
Author(s):  
Sylwia Grabska-Zielińska ◽  
Alina Sionkowska ◽  
Ewa Olewnik-Kruszkowska ◽  
Katarzyna Reczyńska ◽  
Elżbieta Pamuła
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Physicochemical Properties ◽  
Silk Fibroin ◽  
Three Dimensional ◽  
Microscopy Imaging ◽  
Maximum Deformation ◽  
One Step ◽  
Chitosan Blends ◽  
Fourier Transfer Infrared Spectroscopy

The aim of this work was to compare physicochemical properties of three dimensional scaffolds based on silk fibroin, collagen and chitosan blends, cross-linked with dialdehyde starch (DAS) and dialdehyde chitosan (DAC). DAS was commercially available, while DAC was obtained by one-step synthesis. Structure and physicochemical properties of the materials were characterized using Fourier transfer infrared spectroscopy with attenuated total reflectance device (FTIR-ATR), swelling behavior and water content measurements, porosity and density observations, scanning electron microscopy imaging (SEM), mechanical properties evaluation and thermogravimetric analysis. Metabolic activity with AlamarBlue assay and live/dead fluorescence staining were performed to evaluate the cytocompatibility of the obtained materials with MG-63 osteoblast-like cells. The results showed that the properties of the scaffolds based on silk fibroin, collagen and chitosan can be modified by chemical cross-linking with DAS and DAC. It was found that DAS and DAC have different influence on the properties of biopolymeric scaffolds. Materials cross-linked with DAS were characterized by higher swelling ability (~4000% for DAS cross-linked materials; ~2500% for DAC cross-linked materials), they had lower density (Coll/CTS/30SF scaffold cross-linked with DAS: 21.8 ± 2.4 g/cm3; cross-linked with DAC: 14.6 ± 0.7 g/cm3) and lower mechanical properties (maximum deformation for DAC cross-linked scaffolds was about 69%; for DAS cross-linked scaffolds it was in the range of 12.67 ± 1.51% and 19.83 ± 1.30%) in comparison to materials cross-linked with DAC. Additionally, scaffolds cross-linked with DAS exhibited higher biocompatibility than those cross-linked with DAC. However, the obtained results showed that both types of scaffolds can provide the support required in regenerative medicine and tissue engineering. The scaffolds presented in the present work can be potentially used in bone tissue engineering to facilitate healing of small bone defects.

scholarly journals Single Step 2-Port Device De-Embedding Algorithm for Fixture-DUT-Fixture Network Assembly

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1275
Author(s):  
Simone Scafati ◽  
Enza Pellegrino ◽  
Francesco de Paulis ◽  
Carlo Olivieri ◽  
James Drewniak ◽  
...  
Keyword(s):  
Standard Technique ◽  
Single Step ◽  
Scattering Parameters ◽  
Linear Set ◽  
S Parameter ◽  
Parameter Conversion ◽  
Before And After ◽  
One Step ◽  
Typical Measurement

The de-embedding of measurement fixtures is relevant for an accurate experimental characterization of radio frequency and digital electronic devices. The standard technique consists in removing the effects of the measurement fixtures by the calculation of the transfer scattering parameters (T-parameters) from the available measured (or simulated) global scattering parameters (S-parameters). The standard de-embedding is achieved by a multiple steps process, involving the S-to-T and subsequent T-to-S parameter conversion. In a typical measurement setup, two fixtures are usually placed before and after the device under test (DUT) allowing the connection of the device to the calibrated vector network analyzer coaxial ports. An alternative method is proposed in this paper: it is based on the newly developed multi-network cascading algorithm. The matrices involved in the fixture-DUT-fixture cascading gives rise to a non-linear set of equations that is in one step analytically solved in closed form, obtaining a unique solution. The method is shown to be effective and at least as accurate as the standard multi-step de-embedding one.

scholarly journals A Versatile Approach to Access Trimetallic Complexes Based on Trisphosphinite Ligands

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 593
Author(s):  
Juan Miranda-Pizarro ◽  
Macarena G. Alférez ◽  
M. Dolores Fernández-Martínez ◽  
Eleuterio Álvarez ◽  
Celia Maya ◽  
...  
Keyword(s):  
Coordination Chemistry ◽  
Late Transition Metal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Full Characterization ◽  
Metal Precursors ◽  
Straightforward Method ◽  
One Step ◽  
Late Transition

A straightforward method for the preparation of trisphosphinite ligands in one step, using only commercially available reagents (1,1,1-tris(4-hydroxyphenyl)ethane and chlorophosphines) is described. We have made use of this approach to prepare a small family of four trisphosphinite ligands of formula [CH3C{(C6H4OR2)3], where R stands for Ph (1a), Xyl (1b, Xyl = 2,6-Me2-C6H3), iPr (1c), and Cy (1d). These polyfunctional phosphinites allowed us to investigate their coordination chemistry towards a range of late transition metal precursors. As such, we report here the isolation and full characterization of a number of Au(I), Ag(I), Cu(I), Ir(III), Rh(III) and Ru(II) homotrimetallic complexes, including the structural characterization by X-ray diffraction studies of six of these compounds. We have observed that the flexibility of these trisphosphinites enables a variety of conformations for the different trimetallic species.

Sign in / Sign up

Export Citation Format

Share Document