Progress in Developing Nerve Agent Sensors Using Combinatorial Techniques

2003 ◽  
Vol 787 ◽  
Author(s):  
John C. DiCesare ◽  
Jennifer Parker ◽  
Starr N. Horne ◽  
Justin Kita ◽  
Raghu Earni ◽  
...  
Keyword(s):  
Molecular Imprinting ◽  
Sol Gel ◽  
Hydrolysis Product ◽  
Three Dimensional ◽  
Nerve Agents ◽  
Nerve Agent ◽  
Silica Sol ◽  
Sol Gel Synthesis ◽  
Selection Of

ABSTRACTDevelopment of a sensor capable of selective detection of specific nerve agents is imperative in today’s atmosphere of terrorism. The sensor needs to be inexpensive, portable, reliable, absent of false positives and available to all military and first responders. By utilizing the techniques of molecular imprinting, combinatorial chemistry, silica sol-gel synthesis and lanthanide luminescence, a sensor for the detection of the hydrolysis product of the nerve agent soman is being developed. There are many parameters that require investigation in order for the sensor to become a reality. These parameters include 1) the selection of a chelate that can bind to the lanthanide and anchor the nerve agent simulant during the formation of the molecularly imprinted polymer, 2) the determination of the environment best suited for this complex formation, 3) the formation, as well as modification of the silica sol-gel for molecular imprinting to take place, and 4) the proper quantity and ratios of monomers used to create the three dimensional imprint. Key to the success of optimizing these parameters is the development of a combinatorial assay that allows for the synthesis and testing of tens of thousands of combinations of parameters. Work on the development of the combinatorial assay has lead to a method of preparing thin film polymers capable of analyzing the presence of nerve agent simulants. Current work is underway to validate the combinatorial assay and to synthesize and evaluate a library of sensor materials selective for nerve agents.

Enhancement of Uranyl Adsorption Capacity and Selectivity on Silica Sol−Gel Glasses via Molecular Imprinting

1997 ◽  
Vol 9 (11) ◽  
pp. 2521-2525 ◽  
Author(s):  
Sheng Dai ◽  
Y. S. Shin ◽  
C. E. Barnes ◽  
L. M. Toth
Keyword(s):  
Adsorption Capacity ◽  
Molecular Imprinting ◽  
Sol Gel ◽  
Silica Sol ◽  
Gel Glasses

scholarly journals A Comparison of Different Counting Methods for a Holographic Particle Counter: Designs, Validations and Results

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 3006
Author(s):  
Georg Brunnhofer ◽  
Isabella Hinterleitner ◽  
Alexander Bergmann ◽  
Martin Kraft
Keyword(s):  
Three Dimensional ◽  
Nano Particles ◽  
The Novel ◽  
Computational Speed ◽  
Hologram Plane ◽  
Detection And Counting ◽  
Sampling Volume ◽  
Fringe Patterns ◽  
Selection Of

Digital Inline Holography (DIH) is used in many fields of Three-Dimensional (3D) imaging to locate micro or nano-particles in a volume and determine their size, shape or trajectories. A variety of different wavefront reconstruction approaches have been developed for 3D profiling and tracking to study particles’ morphology or visualize flow fields. The novel application of Holographic Particle Counters (HPCs) requires observing particle densities in a given sampling volume which does not strictly necessitate the reconstruction of particles. Such typically spherical objects yield circular intereference patterns—also referred to as fringe patterns—at the hologram plane which can be detected by simpler Two-Dimensional (2D) image processing means. The determination of particle number concentrations (number of particles/unit volume [#/cm 3 ]) may therefore be based on the counting of fringe patterns at the hologram plane. In this work, we explain the nature of fringe patterns and extract the most relevant features provided at the hologram plane. The features aid the identification and selection of suitable pattern recognition techniques and its parameterization. We then present three different techniques which are customized for the detection and counting of fringe patterns and compare them in terms of detection performance and computational speed.

Core/Shell Composite of Self-Assembled Hierarchical Bismuth Oxide/Europium Doped Gadolinium Oxide for Scintillating Detection

2009 ◽  
Vol 1207 ◽  
Author(s):  
Teng-Kuan Tseng ◽  
Jihun Choi ◽  
Mark Davidson ◽  
Paul H Holloway
Keyword(s):  
Bismuth Oxide ◽  
Sol Gel ◽  
Three Dimensional ◽  
Gadolinium Oxide ◽  
Oxide Shell ◽  
Gamma Phase ◽  
Capping Agent ◽  
Self Assembled ◽  
Sol Gel Synthesis ◽  
Heating Up

AbstractA novel three dimensional (3D) self-assembled hierarchical bismuth oxide was prepared via a sol-gel synthesis with the aid of capping agent of polyethylene glycol-8000 (PEG-8000) at 85 ℃ in 45 min. The morphology evolution was studied versus reaction time and interpreted in terms of growth mechanisms. The as-grown 3D hierarchical flower-like bismuth oxide was crystalline cubic gamma-phase. The morphology and crystal phase of these 3D cubic gamma-phase bismuth oxide flowers were not changed with heating up to 600 ℃. The flower-like morphology was attributed to modification of the growth kinetics by the capping agent from the PEG-OH bond bridging with bismuth ions. Europium doped gadolinium oxide shell were further deposited on the bismuth oxide cores through sol-gel synthesis showing good photoluminescence characteristics at 610 and 622 nm under the excitation at 280 nm.

Synthesis and Properties of Hybrid Materials for Ion-Exchange and Complexing Membranes

2013 ◽  
Vol 749 ◽  
pp. 283-288 ◽  
Author(s):  
Yury Pozhidaev ◽  
Oksana Lebedeva ◽  
Evgenya Sipkina ◽  
Alexandra Chesnokova ◽  
Nikolay Ivanov
Keyword(s):  
Hybrid Materials ◽  
Hybrid Composites ◽  
Sol Gel ◽  
Polymer Networks ◽  
Glycidyl Ether ◽  
Three Dimensional ◽  
Polymeric Materials ◽  
Interpenetrating Polymer Networks ◽  
Linear Polymers ◽  
Sol Gel Synthesis

Hybrid materials are attractive for a large range of applications from medicine and biotechnology to telecommunication systems and fuel cells. In the present research we have studied sol-gel synthesis of hybrid composites based on carbofunctional organosilicon monomers N,N-bis-(3-triethoxysilylpropyl) thiocarbamide (I) or 2-{[3-(triethoxysilyl) propyamino} pyridine (II), and copolymers of ethylene glycol vinyl glycidyl ether with vinyl chloride.The polymeric materials were characterized by scanning electron microscope (SEM) and IR-spectroscopy. Gel products possess high thermal stability (decomposition temperatures reach 250 °С) and have developed specific surface (to 20 m2g-1).The synthesized composites comprise semi-interpenetrating polymer networks, consisting of three-dimensional and linear polymers that cannot be separated due to the mechanical interlacing of theirs chains. Hybrid composites have a value of sorption capacity for Pt (IV) ions of 70 (I) and 28 (II) mgg-1. Proton conductivity of membranes based on the synthesized composites is characterized by the values 3.52 10-2(I) and 1.19 10-2(II) Scm-1measured at temperature of 25 °C.

scholarly journals Facile Sol-gel Synthesis of Porous Silicas Using Poly(propylene)imine Dendrimers as Templates

2000 ◽  
Vol 15 (8) ◽  
pp. 1842-1848 ◽  
Author(s):  
Gustavo Larsen ◽  
Edgar Lotero ◽  
Manuel Marquez
Keyword(s):  
Single Molecule ◽  
Sol Gel ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Template Removal ◽  
Synthesis Conditions ◽  
Transmission Electron ◽  
Argon Adsorption ◽  
Poly Propylene ◽  
Sol Gel Synthesis

Commercially available poly(propylene)imine (DAB-Am-32 and DAB-Am-64) dendrimers were used as single-molecule templates to tailor the porosity of silicas via a nonacidic sol-gel method. X-ray diffraction on both the as-prepared (oven-dried at 373 K) and the calcined (833 K) materials revealed that modest contraction took place on template removal and that the cavities created did not achieve three-dimensional ordering under the current synthesis conditions. Transmission electron microscopy of “Pt-stained” samples supported this picture. A modified Horvath–Kawazoe analysis of the argon adsorption isotherms indicated that DAB-Am-64 is a much more effective template than DAB-Am-32. Pyrolysis and oxidation protocols for template removal are also presented.

Non-cytotoxic hybrid bioscaffolds of chitosan-silica: Sol-gel synthesis, characterization and proposed application

2017 ◽  
Vol 178 ◽  
pp. 190-199 ◽  
Author(s):  
Athit Pipattanawarothai ◽  
Chomchai Suksai ◽  
Klaokwan Srisook ◽  
Thanida Trakulsujaritchok
Keyword(s):  
Sol Gel ◽  
Silica Sol ◽  
Sol Gel Synthesis

Freezing Dynamical Sol-gel processes with the controlled environment vitrification system (CEVS)

1987 ◽  
Vol 45 ◽  
pp. 356-357
Author(s):  
J. R. Bellare ◽  
J. K. Bailey ◽  
M. L. Mecartney
Keyword(s):  
Sol Gel ◽  
Particle Surface ◽  
Three Dimensional ◽  
Colloidal Dispersions ◽  
Submicron Particles ◽  
Surface Charges ◽  
Stable Suspension ◽  
Dimensional Network ◽  
Processing Techniques

A sol is a stable suspension of submicron particles in a liquid while a gel is a three dimensional network of these particles which is bicontinuous with the liquid phase. Sol particles are stabilized by surface charges or by steric hindrance of molecules on the particle surface. Sols can be gelled by the agglomeration of the particles; for example, by reducing the inter-particle repulsion with the addition of a salt. The sol-gel transformation is an important industrial, biological and household process. Novel ceramic processing techniques, blood-clotting, and white-sauce manufacturing are some diverse examples. Therefore, there has been extensive interest in relating the gel structure to changes in the physical properties that occur during gelation.Direct observation of thin vitrified films is the preferred technique for microstructural determination of colloidal dispersions in the size range of 1-1000nm.

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