Molecular Building Blocks in Low PH Silicon Sol-Gels: A Silicon-29 NMR Study

1988 ◽  
Vol 121 ◽  
Author(s):  
Larry W. Kelts ◽  
Nancy J. Armstrong
Keyword(s):  
Sol Gel ◽  
Building Blocks ◽  
Low Ph ◽  
Tetraethyl Orthosilicate ◽  
Compact Ring ◽  
Molar Ratios ◽  
Molecular Building Blocks ◽  
Nmr Study ◽  
Ring Structures ◽  
Silicon Sol

ABSTRACTHigh field Silicon-29 NMR is used to study the structural intermediates in tetramethyl and tetraethyl orthosilicate (TMOS and TEOS) low pH sol-gel reactions. Linear oligomers as well as ring components of various sizes are identified and their evolution in the sols is followed. Differences in the number of compact ring structures are related to differences in gel times. Reactions are followed for various silicon alkoxide:water:acid molar ratios.

A silicon-29 NMR study of the structural intermediates in low pH sol-gel reactions

1989 ◽  
Vol 4 (2) ◽  
pp. 423-433 ◽  
Author(s):  
L. W. Kelts ◽  
N. J. Armstrong
Keyword(s):  
Sol Gel ◽  
Low Ph ◽  
Tetraethyl Orthosilicate ◽  
Compact Ring ◽  
Molar Ratios ◽  
Nmr Study ◽  
Ring Structures

Silicon-29 NMR is used to study the structural intermediates in tetramethyl and tetraethyl orthosilicate (TMOS and TEOS) low pH sol-gel reactions. Differences in the number of compact ring structures are related to differences in gel times. Reactions are followed at various silicon: water: acid molar ratios.

A Solid State Multinuclear Magnetic Resonance Study of the Sol-Gel Process using Polysilicate Precursors

1986 ◽  
Vol 73 ◽  
Author(s):  
W. G. Klemperer ◽  
V. V. Mainz ◽  
D. M. Millar
Keyword(s):  
Solid State ◽  
Magnetic Resonance ◽  
Sol Gel ◽  
Building Blocks ◽  
Magnetic Resonance Study ◽  
Solvent Content ◽  
Molecular Building Blocks ◽  
Nmr Study ◽  
Sol Gel Process ◽  
Nmr Techniques

ABSTRACTA solid state multinuclear NMR study of the sol-gel process was performed using the molecular building blocks tetramethoxysilane, hexamethoxydisiloxane, octamethoxytrisiloxane and octamethoxyoctasilsesquioxane as precursor monomers. Water content, solvent content, and hydrolysis/condensation processes were monitored using 17O, 13C, and 29Si FT, FTMAS and CPMAS NMR techniques.

Self-Assembly of Proteins into Three-Dimensional Structures Using Bio-Conjugation

2014 ◽  
Vol 1663 ◽  
Author(s):  
Garima Thakur ◽  
Kovur Prashanthi ◽  
Thomas Thundat
Keyword(s):  
Self Assembly ◽  
Three Dimensional ◽  
Gold Surface ◽  
Building Blocks ◽  
Growth Conditions ◽  
Base Layer ◽  
Chemical Structures ◽  
Molecular Building Blocks ◽  
Ring Structures ◽  
Self Assembled

ABSTRACTSelf–assembly of molecular building blocks provides an interesting route to produce well-defined chemical structures. Tailoring the functionalities on the building blocks and controlling the time of self-assembly could control the properties as well as the structure of the resultant patterns. Spontaneous self-assembly of biomolecules can generate bio-interfaces for myriad of potential applications. Here we report self-assembled patterning of human serum albumin (HSA) protein in to ring structures on a polyethylene glycol (PEG) modified gold surface. The structure of the self-assembled protein molecules and kinetics of structure formation entirely revolved around controlling the nucleation of the base layer. The formation of different sizes of ring patterns is attributed to growth conditions of the PEG islands for bio-conjugation. These assemblies might be beneficial in forming structurally ordered architectures of active proteins such as HSA or other globular proteins.

Polynuclear Titanium Oxoalkoxides: Molecular Building Blocks for New Materials?

1992 ◽  
Vol 271 ◽  
Author(s):  
Y. W. Chen ◽  
W. G. Klemperer ◽  
C. W. Park
Keyword(s):  
Solid State ◽  
Metal Oxide ◽  
Good Yield ◽  
Sol Gel ◽  
Building Blocks ◽  
Mas Nmr ◽  
Core Structure ◽  
New Materials ◽  
Molecular Building Blocks

ABSTRACTThe [Ti7O4](OEt)20 molecule, Et = C2H5, is very reactive toward ethanol, and its [Ti7O4] metal oxide core structure is largely decomposed in <10 minutes. The [Ti16O16](OEt232 molecule, however, has a [Ti16O16] core structure which is relatively stable toward alcoholysis, and solid state 17O MAS NMR experiments using selective 17O labeling techniques show that this core structure is preserved in good yield during sol-gel polymerization.

Sol-gel transition in silica alkaline solutions. A NMR study

1994 ◽  
Vol 91 ◽  
pp. 901-908 ◽  
Author(s):  
H Zanni ◽  
P Nieto ◽  
L Fernandez ◽  
R Couty ◽  
P Barret ◽  
...  
Keyword(s):  
Sol Gel ◽  
Alkaline Solutions ◽  
Nmr Study ◽  
Sol Gel Transition ◽  
Gel Transition

A First Principles Approach for Partitioning Linear Response Properties into Additive and Cooperative Contributions

2018 ◽  
Author(s):  
Daniel Lambrecht ◽  
Eric Berquist
Keyword(s):  
First Principles ◽  
Linear Response ◽  
Building Blocks ◽  
Field Method ◽  
Response Property ◽  
Response Properties ◽  
Consistent Field ◽  
Molecular Building Blocks ◽  
Self Consistent ◽  
Self Consistent Field

We present a first principles approach for decomposing molecular linear response properties into orthogonal (additive) plus non-orthogonal/cooperative contributions. This approach enables one to 1) identify the contributions of molecular building blocks like functional groups or monomer units to a given response property and 2) quantify cooperativity between these contributions. In analogy to the self consistent field method for molecular interactions, SCF(MI), we term our approach LR(MI). The theory, implementation and pilot data are described in detail in the manuscript and supporting information.

A new molecular building blocks: Synthesis, crystal structure, magnetic and spectroscopic properties of Cu(II) and Ni(II) macrocyclic complexes

Polyhedron ◽  
2011 ◽  
Vol 30 (15) ◽  
pp. 2550-2557 ◽  
Author(s):  
Katarzyna Suracka ◽  
Alina Bieńko ◽  
Jerzy Mroziński ◽  
Rafał Kruszyński ◽  
Dariusz Bieńko ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Building Blocks ◽  
Spectroscopic Properties ◽  
Macrocyclic Complexes ◽  
Molecular Building Blocks

scholarly journals Acid-Catalysed Liquid-to-Solid Transitioning of Arylazoisoxazole Photoswitches

2021 ◽  
Author(s):  
Luuk Kortekaas ◽  
Julian Simke ◽  
Niklas Arndt ◽  
Marcus Böckmann ◽  
Nikos Doltsinis ◽  
...  
Keyword(s):  
Building Blocks ◽  
Vital Role ◽  
Responsive Materials ◽  
Molecular Building Blocks ◽  
Physical Changes

Molecular photoswitches play a vital role in the development of responsive materials. These molecular building blocks are particularly attractive when multiple stimuli can be combined to bring about physical changes,...

Liquid state 29Si NMR study on the sol-gel reaction mechanisms of ormosils

1993 ◽  
Vol 159 (1-2) ◽  
pp. 65-72 ◽  
Author(s):  
Takashi Iwamoto ◽  
Kazuki Morita ◽  
John D. Mackenzie
Keyword(s):  
Reaction Mechanisms ◽  
Liquid State ◽  
Sol Gel ◽  
29Si Nmr ◽  
Nmr Study

Control of Hierarchically Ordered Positive and Negative Replicas of Wood Cellular Structures by Surfactant-Directed Sol-Gel Mineralization

2002 ◽  
Vol 726 ◽  
Author(s):  
Yongsoon Shin ◽  
Jun Liu ◽  
Li-Qiong Wang ◽  
Jeong Ho Chang ◽  
William D. Samuels ◽  
...  
Keyword(s):  
Silicic Acid ◽  
Cell Walls ◽  
Cellular Structure ◽  
Sol Gel ◽  
Ceramic Materials ◽  
Silica Particles ◽  
Low Ph ◽  
Cellular Structures ◽  
Inner Surface

AbstractWe here report the synthesis of ordered ceramic materials with hierarchy produced by an in-situ mineralization of ordered wood cellular structures with surfactant-templated sol-gel at different pH. At low pH, a silicic acid is coated onto inner surface of wood cellular structure and it penetrates into pores left, where degraded lignin and hemicellulose are leached out, to form a positive replica, while at high pH the precipitating silica particles due to fast condensation clog the cells and pit structures to form a negative replica of wood. The calcined monoliths produced in different pHs contain ordered wood cellular structures, multi-layered cell walls, pits, vessels well-preserved with positive or negative contrasts, respectively. The surfactant-templated mineralization produces ordered hexagonal nanopores with 20Å in the cell walls after calcination.

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