Characterization Of SnO2 Nanoparticles Deposited Via Layer-by-Layer Self Assembly And Investigation Of Their Sensing Properties

2002 ◽  
Vol 739 ◽  
Author(s):  
R. C. Ghan ◽  
Y. Lvov ◽  
R. S. Besser
Keyword(s):  
Self Assembly ◽  
High Selectivity ◽  
Sno2 Nanoparticles ◽  
Test Chamber ◽  
The Self ◽  
Layer By Layer ◽  
Product Analysis ◽  
Glass Substrates ◽  
Self Assembled

ABSTRACTA technique of Layer-by-Layer (LbL) self-assembly is used to deposit SnO2 nanoparticles on Quartz Crystal Microbalance (QCM) resonators, and on glass substrates which the authors believe has not been previously reported. Characterization of self-assembled SnO2 layers has been performed using QCM, Scanning Electron Microscopy (SEM), and Zeta Potential analysis.We have successfully deposited SnO2 nanoparticles on QCM resonator using self-assembly technique. LbL self-assembly is a method of organization of ultra-thin films by interlayer electrostatic attraction. The thickness and mass of the self-assembled layers can be characterized by the frequency shift obtained using the QCM and empirical equations relating change in frequency with mass and thickness of deposited layers. The deposition of SnO2 nanolayers exhibited a linear reproducibility and the process of self-assembly was independent of the residence time of QCM resonator in the SnO2 nanoparticle colloidal solution. High resolution SEM analysis reveals that the SnO2 nanoparticle layers are uniformly deposited across the entire substrate. Electrical characterization was performed on SnO2 nanoparticle layers self-assembled on glass substrates which were patterned for two point (current-voltage) IV characteristic measurements. Two classes of samples were used. One sample was self-assembled glass substrate patterned with electrical contacts and calcined (baked at 350°C for one hour) to eliminate interlayered polyions and the other sample was not calcined. Results revealed that the calcined samples demonstrated linear ohmic behavior but the uncalcined showed some spurious points which we believe are due to the polyion layers.Characterization of the self-assembled SnO2 nanoparticles is being carried out with the intention of fabricating a high-selectivity μ-gas sensor. A test chamber has been fabricated and results of resistance behavior of the sensor with variation in temperature have been presented.The sensor can find applications in high selectivity sensing of chemical, industrial, domestic, and hazardous environments. After further research and development, this μ-gas sensors could be made generic to sense a variety of gases and employed for integrated on-chip product analysis in multiple chemical microsystem applications.

Dumbbell-shaped dendrimers — Synthesis and self-assembly

2008 ◽  
Vol 86 (6) ◽  
pp. 540-547 ◽  
Author(s):  
Tatiana Vassilieff ◽  
Ashok Kakkar
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Layer By Layer ◽  
Acid Base ◽  
Detailed Characterization ◽  
Generation Number ◽  
Backbone Structure

We report on the synthesis and detailed characterization of dendrimers that evolve symmetrically from a linear core of 2-butyne-1,4-diol with 3,5-dihydroxybenzyl alcohol based dendron arms. The divergent layer-by-layer build-up of the dumbbell-shaped dendrimers is based on simple acid–base hydrolytic chemistry of bis(dimethylamino)dimethylsilane with OH-terminated molecules. The self-assembly of these dendrimers in THF and water is significantly influenced by their generation number, the backbone structure, and the solvent.Key words: dendrimers, divergent synthesis, macromolecules, self-assembly

scholarly journals Multilayer Self-Assemblies as Electronic and Optical Materials

1997 ◽  
Vol 488 ◽  
Author(s):  
DeQuan Li ◽  
M. Lütt ◽  
Xiaobo Shi ◽  
M. R. Fitzsimmons
Keyword(s):  
Thin Film ◽  
Self Assembly ◽  
Film Growth ◽  
Building Blocks ◽  
Layer Growth ◽  
The Self ◽  
Growth Surface ◽  
Layer By Layer ◽  
Self Assembled ◽  
Average Electron

AbstractThe layer-by-layer growth of film structures consisting of sequential depositions of oppositely charged polymers and macrocycles (ring-shaped molecules) have been constructed using molecular self-assembly techniques. These self-assembled thin films were characterized with X-ray reflectometry, which yielded (1) the average electron density, (2) the average thicknesses, and (3) the roughness of the growth surface of the self-assembled multilayer of macrocycles and polymers. These observations suggest that inorganic-organic interactions play an important role during the initial stages of thin-film growth, but less so as the thin film becomes thicker. Optical absorption techniques were also used to characterize the self-assembled multilayers. Phorphyrin and phthalocyanine derivatives were chosen as the building blocks of the self-assembled multilayers because of their interesting optical properties.

Self-assembly of a Benzothiazolone Conjugate to Panchromatic Fluorescent Fibres and its Application in Cellular Imaging

2021 ◽  
Author(s):  
Vivekshinh Kshtriya ◽  
Bharti Koshti ◽  
Ankit Gangrade ◽  
Ashadul Haque ◽  
Ramesh Singh ◽  
...  
Keyword(s):  
Self Assembly ◽  
Cellular Imaging ◽  
The Self ◽  
Synthesis And Characterization ◽  
Self Assembled

We report the synthesis and characterization of the self-assembled structures formed by 4-chloro-2(3H)-benzothiazolone (CBT) to panchromatic fibres and its application in cellular imaging. The aggregation properties of the synthesized compound...

Self-Assembled Optical Gratings with Banana-Shaped Liquid Crystals

2010 ◽  
Vol 428-429 ◽  
pp. 12-23 ◽  
Author(s):  
Yuan Ming Huang
Keyword(s):  
Liquid Crystals ◽  
Self Assembly ◽  
Red Light ◽  
Diffraction Gratings ◽  
The Self ◽  
Two Dimensional ◽  
Glass Substrates ◽  
Self Assembled ◽  
Optical Gratings ◽  
Diffraction Patterns

We demonstrated that a homologous series of banana-shaped liquid crystals, 1,3-phenylene bis(4-alkyloxybenzylideneamine), could assemble themselves into various kinds of groove-free diffraction gratings when their isotropic melts were slowly cooled into mesophases between two pieces of glass substrates. The groove-free diffraction gratings included one-dimensional parallel gratings, two-dimensional crossed gratings, two-dimensional fan-shaped gratings and two-dimensional circular gratings. Characterization by means of polarized optical microscopy showed that a pattern of periodic modulation of the refractive index was developed in the thin films formed by the banana-shaped compound. Our laser light diffraction experiments confirmed that these groove-free gratings could effectively diffract the incident red light from a helium-neon laser. On the basis of the diffraction equations derived for the self-assembled groove-free optical gratings, the diffraction patterns were simulated for the parallel gratings, orthogonally crossed gratings, fan-shaped gratings and circular gratings, respectively, and good agreement was achieved. The mechanisms on the self-assembly of the banana-shaped molecules were discussed in terms of intermolecular interactions. Our work provides an alternative method for manufacturing diffraction gratings by harnessing the self-assembly of banana-shaped molecules.

FABRICATION AND CHARACTERIZATION OF SPIN SELF-ASSEMBLED PPV/MONTMORILLONITE MULTILAYER THIN FILMS

2004 ◽  
Vol 13 (03n04) ◽  
pp. 581-586
Author(s):  
TAE-HO KIM ◽  
O OK PARK
Keyword(s):  
Thin Films ◽  
Self Assembly ◽  
Environmental Stability ◽  
Phenylene Vinylene ◽  
Multilayer Thin Films ◽  
Layer By Layer ◽  
Assembly Method ◽  
Fabrication And Characterization ◽  
Self Assembled

Multilayer nanostructural thin films through a layer-by-layer spin self-assembly method were prepared using poly(p-phenylene vinylene)/montmorillonite. Sodium montmorillonite particles exfoliated into single sheets and cationic PPV precursor and such anionic MMT plates were spin self-assembled by electrostatic attraction. Self-assembled MMT layers blocked the penetration of oxygen and moisture and they reduced the photo-oxidation of the emitting material. Spin self-assembled films showed higher environmental stability and luminescence, and their PL spectra were somewhat different from that of bulk PPV films.

Flexible Layer-by-Layer Self-Assembled Graphene Based Glucose Biosensors

2011 ◽  
Author(s):  
Bo Zhang ◽  
Tony Zhengyu Cui
Keyword(s):  
Self Assembly ◽  
Low Cost ◽  
Glucose Biosensor ◽  
Layer By Layer ◽  
Glucose Biosensors ◽  
Flexible Polymer ◽  
Assembly Technique ◽  
Self Assembled ◽  
The Cost

The manufacture and characterization of glucose biosensor based on layer by layer self assembled graphene are presented. Due to self assembly technique and flexible polymer substrate, the cost of the biosensor is very competitive. The resolution of the graphene based biosensor reaches down to 10 pM, which shows greater advantages over CNT based biosensor under the same conditions. The response time of graphene biosensor is less than 3 s, which is much faster than other materials and methods. This work demonstrates that graphene and polymers are very promising materials for the applications of low-cost glucose biosensors.

Preparation and Characterization of Quaternary Chitosan/sodium Alginate Self-Assembled Microcapsules

2012 ◽  
Vol 554-556 ◽  
pp. 263-267
Author(s):  
Hui Chen ◽  
Xiao Hui Wang ◽  
Dong Li ◽  
Yan Zhu Guo ◽  
Run Cang Sun
Keyword(s):  
Sodium Alginate ◽  
Self Assembly ◽  
Colloidal Particles ◽  
Red Light ◽  
Formaldehyde Resin ◽  
Layer By Layer ◽  
Light Emitting ◽  
Resin Microspheres ◽  
Self Assembled

Biocompatible quaternary chitosan/sodium alginate multilayer microcapsules were prepared by layer-by-layer (LBL) self-assembly on the template of monodispersed melamine formaldehyde resin microspheres (MF). The process of self-assembly was monitored by measuring the surface zeta-potential of colloidal particles. The particle size was determined by digital light scattering (DLS) after each deposition, and the average thickness of monolayer film was revealed to be 3.9 nm. Using rhodamine B-labeled quaternary chitosan as the positive polyelectrolyte and sodium alginate as the negative polyelectrolyte, self-assembled multilayer microcapsules with strong red-light emitting were obtained and observed with fluorescence microscope. The fluorescent microcapsules self-assembled from the biocompatible natural polysaccharides may be potentially applied in drug delivery and fluorescence diagnosis.

Fabrication and Characterization of the Multilayer Film Containing Polyoxometalate with Pendant Support-Ligand

2007 ◽  
Vol 336-338 ◽  
pp. 2235-2237
Author(s):  
Hui Yuan Ma ◽  
Jun Peng ◽  
Fu Ping Wang ◽  
Bao Xia Dong
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Property ◽  
Self Assembly ◽  
Multilayer Film ◽  
Interface Roughness ◽  
The Self ◽  
Layer By Layer ◽  
The Mean ◽  
Fabrication And Characterization

A novel nanosized multilayer film containing polyoxometalate anion with a pendant supportligand α-[SiW11O39Co(H3P2O7)]7- (abbr. SiW11Co-P2O7) and poly(diallyldimethyl ammonium chloride (PDDA) was fabricated by layer-by-layer self-assembly. The multilayer film was characterized by XPS, UV-vis, AFM and ESR. The mean interface roughness was about 2.0 nm, calculated from an area of 0.5 × 0.5 μm2. The electrochemical property was studied by the cyclic voltammetry, the results indicating that the self-assembly film exhibited favorable electrochemical behavior of polyoxometalate.

Molecular Self-Assembly Routes to Optically Functional Thin Films: Electroluminescent Multilayer Structures

1997 ◽  
Vol 488 ◽  
Author(s):  
W. Li ◽  
J. E. Malinsky ◽  
H. Chou ◽  
W. Ma ◽  
L. Geng ◽  
...  
Keyword(s):  
Self Assembly ◽  
Chemical Characterization ◽  
Hole Transport ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Hole Transport Layer ◽  
Layer By Layer ◽  
Self Assembled ◽  
Precursor Molecules

AbstractThis contribution describes the use of layer-by-layer self-limiting siloxane chemisorption processes to self-assemble structurally regular multilayer organic LED (OLED) devices. Topics discussed include: 1) the synthesis of silyl-functionalized precursor molecules for hole transport layer (HTL), emissive layer (EML), and electron transport layer (ETL) self-assembly, 2) the use of layer-by-layer self-assembly for ITO electrode modification/passivation/hole-electron balancing in a vapor-deposited device, 3) the microstructure/chemical characterization of HTL self-assembly using a prototype triarylamine precursor, 4) fabrication and properties of a hybrid self-assembled + vapor deposited two-layer LED, 4) fabrication and properties of a fully self-assembled two-layer OLED.

Nanoscale Self-Assembly Using Ion and Electron Beam Techniques: A Rapid Review

MRS Advances ◽  
2020 ◽  
Vol 5 (64) ◽  
pp. 3507-3520
Author(s):  
Chunhui Dai ◽  
Kriti Agarwal ◽  
Jeong-Hyun Cho
Keyword(s):  
Electron Beam ◽  
Self Assembly ◽  
Ion Beam ◽  
Three Dimensional ◽  
The Self ◽  
Stress Generation ◽  
Rapid Review ◽  
High Yield ◽  
3D Nanostructures ◽  
Self Assembled

AbstractNanoscale self-assembly, as a technique to transform two-dimensional (2D) planar patterns into three-dimensional (3D) nanoscale architectures, has achieved tremendous success in the past decade. However, an assembly process at nanoscale is easily affected by small unavoidable variations in sample conditions and reaction environment, resulting in a low yield. Recently, in-situ monitored self-assembly based on ion and electron irradiation has stood out as a promising candidate to overcome this limitation. The usage of ion and electron beam allows stress generation and real-time observation simultaneously, which significantly enhances the controllability of self-assembly. This enables the realization of various complex 3D nanostructures with a high yield. The additional dimension of the self-assembled 3D nanostructures opens the possibility to explore novel properties that cannot be demonstrated in 2D planar patterns. Here, we present a rapid review on the recent achievements and challenges in nanoscale self-assembly using electron and ion beam techniques, followed by a discussion of the novel optical properties achieved in the self-assembled 3D nanostructures.

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