Organic/Inorganic Langmuir-Blodgeti Films Based on Metal Phosphonates

1997 ◽  
Vol 488 ◽  
Author(s):  
Daniel R. Talham ◽  
Gail E. Fanucci ◽  
Melissa A. Petruska ◽  
Candace T. Seip
Keyword(s):  
Thin Film ◽  
Solid State ◽  
Phosphonic Acid ◽  
Design Constraints ◽  
Lb Films ◽  
Langmuir Blodgett ◽  
Metal Phosphonates ◽  
Metal Phosphonate ◽  
The Stability ◽  
Film Assembly

AbstractLangmuir-Blodgett (LB) bilayers of organophosphonic acids can be prepared where the phosphonic acid headgroups bind metal ions to form the same layered extended-solid structures present in solid-state metal phosphonates. The inorganic extended-solid network enhances the stability of the LB films, but can also be designed to introduce physical properties, such as magnetism, that are typical of the inorganic solid-state. By preparing films based on functionalized organophosphonic acids, the metal phosphonate approach can be used to produce “dualnetwork” LB films, where both the organic and inorganic networks add function to the thin film assembly. To begin to understand the design constraints associated with dual-network metal phosphonate films, LB bilayers of a phosphonic acidderivatized azobenzene amphiphile are formed with Cd2+ and La3+ and the structures are compared to octadecylphosphonate LB films prepared with the same metals.

New Class of Microporous Materials: Porous Metal Phosphonate Thin Films

1996 ◽  
Vol 431 ◽  
Author(s):  
Lori A. Vermeulen ◽  
J. Pattanayak ◽  
Travis Fisher ◽  
Monica Hansford ◽  
Scott J. Burgmeyer
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Porous Metal ◽  
Porous Solids ◽  
New Class ◽  
Metal Phosphonates ◽  
Metal Phosphonate ◽  
Potential Applications ◽  
Shape Selective ◽  
Film Assembly

AbstractSolid state metal phosphonates (M(O3P-R-PO3) or M(O3P-R)2 (M = metal)) have layered structures where the metal atoms lie in planar sheets and the intervening R groups take up the interlamellar space. Microporous metal phosphonates can be prepared by reaction of the metal with a mixture of large and small phosphonates (M(O3P-LARGE)x(O3P-SMALL)2-x. The larger group acts as a pillar that holds the layers apart. Void spaces result from the presence of the smaller groups. The porous nature of these solids make them potential candidates for applications as sensors, size- and shape- selective catalysts, and chromatographic materials. Metal diphosphonates (M(O3P-R-PO3) can also be prepared one layer at a time on a surface, resulting in the construction of interesting superstructures that are not accessible through the solid state synthesis. For example, these superstructures can contain different components in sequential layers and may have applications in energy conversion, vectorial electron transport, and NLO devices. The preparation of microporous thin films would combine the desirable potential applications of the porous solids with the interesting parallel superstructures that can be prepared from the thin film assemblies. We report our progress toward the construction of microporous metal phosphonate thin films. The two methods that are currently being developed include: 1) phosphonate exchange of pre-assembled films, and 2) co-deposition of different large and small phosphonates during film assembly.

Incorporating Inorganic Extended Lattice Structures into Langmuir—Blodgett Films: Comparing Metal Phosphonate LB Films to Their Solid-State Analogs

1997 ◽  
Vol 19 (3) ◽  
pp. 133-151 ◽  
Author(s):  
Daniel R. Talham ◽  
Candace T. Seip ◽  
Scott Whipps ◽  
Gail E. Fanucci ◽  
Melissa A. Petruska ◽  
...  
Keyword(s):  
Solid State ◽  
Lattice Structures ◽  
Lb Films ◽  
Langmuir Blodgett ◽  
Metal Phosphonate ◽  
Langmuir Blodgett Films

Insights into Potent Therapeutical Antileukemic Agent L-glutaminase Enzyme Under Solid-state Fermentation: A Review

2020 ◽  
Vol 21 (3) ◽  
pp. 211-220 ◽  
Author(s):  
Chandrasai Potla Durthi ◽  
Madhuri Pola ◽  
Satish Babu Rajulapati ◽  
Anand Kishore Kola
Keyword(s):  
Solid State ◽  
Solid State Fermentation ◽  
Food Industry ◽  
Energy Requirement ◽  
Production Studies ◽  
Wide Range ◽  
Hybridoma Technology ◽  
Bacteria And Fungi ◽  
The Stability ◽  
Glutaminase Activity

Aim & objective: To review the applications and production studies of reported antileukemic drug L-glutaminase under Solid-state Fermentation (SSF). Overview: An amidohydrolase that gained economic importance because of its wide range of applications in the pharmaceutical industry, as well as the food industry, is L-glutaminase. The medical applications utilized it as an anti-tumor agent as well as an antiretroviral agent. L-glutaminase is employed in the food industry as an acrylamide degradation agent, as a flavor enhancer and for the synthesis of theanine. Another application includes its use in hybridoma technology as a biosensing agent. Because of its diverse applications, scientists are now focusing on enhancing the production and optimization of L-glutaminase from various sources by both Solid-state Fermentation (SSF) and submerged fermentation studies. Of both types of fermentation processes, SSF has gained importance because of its minimal cost and energy requirement. L-glutaminase can be produced by SSF from both bacteria and fungi. Single-factor studies, as well as multi-level optimization studies, were employed to enhance L-glutaminase production. It was concluded that L-glutaminase activity achieved by SSF was 1690 U/g using wheat bran and Bengal gram husk by applying feed-forward artificial neural network and genetic algorithm. The highest L-glutaminase activity achieved under SSF was 3300 U/gds from Bacillus sp., by mixture design. Purification and kinetics studies were also reported to find the molecular weight as well as the stability of L-glutaminase. Conclusion: The current review is focused on the production of L-glutaminase by SSF from both bacteria and fungi. It was concluded from reported literature that optimization studies enhanced L-glutaminase production. Researchers have also confirmed antileukemic and anti-tumor properties of the purified L-glutaminase on various cell lines.

Circular dichroism and infrared study of β-turn formation in repeat peptides of elastin

1987 ◽  
Vol 52 (5) ◽  
pp. 1356-1361
Author(s):  
S. Abdel Rahman ◽  
M. Elsafty ◽  
A. Hattaba
Keyword(s):  
Circular Dichroism ◽  
Solid State ◽  
Ir Spectra ◽  
Chain Length ◽  
Room Temperature ◽  
Infrared Study ◽  
Feature Characteristic ◽  
C 50 ◽  
The Stability ◽  
Circular Dichroïsm

The conformation of elastin-like peptides Boc-Ala-Pro-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM were examined in solution using circular dichroism at 30 °C, 50 °C, and 70 °C and in solid state by IR at room temperature. The studies show that the β-turn is a significant conformational feature for peptides under investigation in solution at 30 °C and 50 °C, but at 70 °C the tetra, hexa, and decapeptides show the CD feature characteristic of the β-structure while the dodecapeptide spectra show the presence of β-turn which indicates the stability of the β-turn at this chain length. The IR spectra show that in the solid state at room temperature all investigated peptides assume essentially a β-turn except the tetrapeptide which present evidence of antiparallel β-structure. The β-turn contribution in the IR spectra increases with the increase of the chain length of the peptide.

scholarly journals Solid State NMR Spectroscopy a Valuable Technique for Structural Insights of Advanced Thin Film Materials: A Review

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1494
Author(s):  
Mustapha El Hariri El Nokab ◽  
Khaled O. Sebakhy
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solid State ◽  
Solid State Nmr ◽  
Pulse Sequences ◽  
3D Structure ◽  
Spectroscopic Techniques ◽  
Film Research ◽  
Versatile Technique ◽  
Work Done

Solid-state NMR has proven to be a versatile technique for studying the chemical structure, 3D structure and dynamics of all sorts of chemical compounds. In nanotechnology and particularly in thin films, the study of chemical modification, molecular packing, end chain motion, distance determination and solvent-matrix interactions is essential for controlling the final product properties and applications. Despite its atomic-level research capabilities and recent technical advancements, solid-state NMR is still lacking behind other spectroscopic techniques in the field of thin films due to the underestimation of NMR capabilities, availability, great variety of nuclei and pulse sequences, lack of sensitivity for quadrupole nuclei and time-consuming experiments. This article will comprehensively and critically review the work done by solid-state NMR on different types of thin films and the most advanced NMR strategies, which are beyond conventional, and the hardware design used to overcome the technical issues in thin-film research.

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