scholarly journals Neat Linear Polysiloxane-Based Ionic Polymers: Insights into Structure-Based Property Modifications and Applications

Macromol ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 2-17
Author(s):  
Louis Poon ◽  
Jacob R. Hum ◽  
Richard G. Weiss
Keyword(s):  
Short Review ◽  
Ionic Polymers ◽  
Static Properties ◽  
Structural Variations ◽  
Diverse Range ◽  
Bulk Properties ◽  
Soft Solids ◽  
Molecular Weights ◽  
Polymer Liquids ◽  
Viscous Polymer

A diverse range of linear polysiloxane-based ionic polymers that are hydrophobic and highly flexible can be obtained by substituting the polymers with varying amounts of ionic centers. The materials can be highly crystalline solids, amorphous soft solids, poly(ionic) liquids or viscous polymer liquids. A key to understanding how structural variations can lead to these different materials is the establishment of correlations between the physical (dynamic and static) properties and the structures of the polymers at different distance scales. This short review provides such correlations by examining the influence of structural properties (such as molecular weights, ion pair contents, and ion types) on key bulk properties of the materials.

scholarly journals The Influence of Surfactant (SDS) on the Adsorption Properties of Polyvinyl Alcohol and Polyethylene Glycol in an Alumina/Solution System

2002 ◽  
Vol 20 (6) ◽  
pp. 573-582 ◽  
Author(s):  
S. Chibowski ◽  
M. Paszkiewicz ◽  
M. Wiśniewska
Keyword(s):  
Polyethylene Glycol ◽  
Polyvinyl Alcohol ◽  
Adsorption Layer ◽  
Sodium Dodecyl ◽  
Adsorption Properties ◽  
Degree Of Hydrolysis ◽  
Ionic Polymers ◽  
Solution System ◽  
Molecular Weights ◽  
Polymer Surfactant

The influence of sodium dodecyl sulphate (SDS) on the adsorption properties of non-ionic polymers, i.e. polyethylene glycol (PEG) and polyvinyl alcohol (PVA), at the Al2O3/solution interface was studied. Measurements for various molecular weights and for various amounts of functional groups on the polymer macromolecules were undertaken and the results obtained discussed in the light of these variations. Studies of the mutual interactions of the polymer–surfactant system in aqueous solution were helpful in explaining the equilibria involved in the Al2O3/polymer solution system in the presence of SDS. The thickness of the adsorption layer was determined by viscometric methods and the influence of the degree of hydrolysis of PVA on the structure of the adsorption layer demonstrated.

1,4-Azaborines: Origin, Modern Synthesis, and Applications as Optoelectronic Materials

Synthesis ◽  
2021 ◽  
Author(s):  
Hee Nam Lim ◽  
Wan Pyo Hong ◽  
Inji Shin
Keyword(s):  
Recent Progress ◽  
Short Review ◽  
Research Field ◽  
Modern Synthesis ◽  
Optoelectronic Properties ◽  
Optoelectronic Materials ◽  
Structural Variations ◽  
Heteroaromatic Compounds ◽  
Synthetic Methodologies ◽  
Boron Nitrogen

AbstractThis short review summarizes the origins and recent progress in 1,4-azaborine research, focusing on synthetic methodologies. Academic laboratories have made significant efforts to generate boron-nitrogen-containing heteroaromatic compounds that mimic arenes. 1,2-, 1,3-, and 1,4-Azaborine motifs have provided breakthrough molecules in applications ranging from medicines to materials. Owing to recent advances in polyaromatic 1,4-azaborine synthesis and applications in industry, the research field is currently undergoing a renaissance. Photo- and electroluminescent properties driven by distinct structural variations are key components in the design of novel 1,4-azaborine structures. In this review, seminal reports on the synthesis of simple 1,4-azaborines to complex π-extended structures are briefly highlighted together along with key optoelectronic properties.1 Introduction2 Non-Fused 1,4-Azaborines3 Monobenzo-Fused 1,4-Azaborines4 Dibenzo-Fused 1,4-Azaborines and Their Derivatives5 Ladder-Type 1,4-Azaborines6 Complex 1,4-Azaborines7 Optoelectronic Properties of Key 1,4-Azaborines8 Conclusion and Outlook

Mixing of viscous polymer liquids

2000 ◽  
Vol 12 (6) ◽  
pp. 1411-1416 ◽  
Author(s):  
Jason R. Stokes ◽  
David V. Boger
Keyword(s):  
Polymer Liquids ◽  
Viscous Polymer

Unsaturated ladder polymers: Structural variations and improved molecular weights

1995 ◽  
Vol 7 (6) ◽  
pp. 544-546 ◽  
Author(s):  
Benediki Schlicke ◽  
Heike Schirmer ◽  
Arnutlf-Dieter Schlüter
Keyword(s):  
Structural Variations ◽  
Molecular Weights ◽  
Ladder Polymers

HELIX: a new modular nucleic acid crystallization screen

2014 ◽  
Vol 47 (3) ◽  
pp. 948-955 ◽  
Author(s):  
Julia Viladoms ◽  
Gary N. Parkinson
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Data Bank ◽  
Diverse Range ◽  
X Ray Crystallography ◽  
Molecular Weights ◽  
Anomalous Data ◽  
Crystallization Conditions ◽  
Nucleic Acid Structures ◽  
Screen Layout

Crystallization of nucleic acids remains a bottleneck to their structural characterization by X-ray crystallography. A new 96-well-format initial screen for nucleic acids, called HELIX, has been developed at UCL School of Pharmacy, London, on the basis of a detailed analysis of the crystallization conditions from 1450 nucleic acid structures deposited in the Protein Data Bank (PDB), combined with observations and experience acquired in the authors' nucleic acids crystallography laboratory during the crystallization of DNA/RNA quadruplexes and ligand complexes. Despite using traditional buffers, precipitants and salts, the resulting modular screen is designed to offer a variety of approaches to enhance successful crystallization of oligonucleotides with a diverse range of topologies, sequences and molecular weights. HELIX includes a set of 24 conditions divided into four sets that can be mixed (inter- and intra-set) to provide a customizable orthogonal screening tool for experienced users, termed VariX. Additionally, mindful of synchrotron anomalous data collection, cacodylate buffers are avoided in the formulations and an optimized cryocrystallization module is included. This article reviews the crystallization trends and data derived from the PDB and discusses the HELIX screen layout, formulation and results from in-house crystallization trials.

Tetrahydropyranyl ether (THPE) formation in hydroxyl group protection and conversion to other useful functionalities

RSC Advances ◽  
2014 ◽  
Vol 4 (40) ◽  
pp. 21121-21130 ◽  
Author(s):  
Brijesh Kumar ◽  
Mushtaq A. Aga ◽  
Abdul Rouf ◽  
Bhahwal A. Shah ◽  
Subhash C. Taneja
Keyword(s):  
Short Review ◽  
Direct Conversion ◽  
Hydroxyl Group ◽  
Reaction Conditions ◽  
Complex Molecules ◽  
Diverse Range ◽  
Tetrahydropyranyl Ether

This short review highlights the various methods of formation of tetrahydropyranyl ethers (THPEs) as a method for the protection of simple alcohols as well as a diverse range of complex molecules, using a variety of reagents and reaction conditions including their direct conversion to other useful functionalities.

scholarly journals Desktop Fabrication of Lab-On-Chip Devices on Flexible Substrates: A Brief Review

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 126 ◽  
Author(s):  
Ahmad Zaman Qamar ◽  
Mohtashim Hassan Shamsi
Keyword(s):  
High School Students ◽  
Low Cost ◽  
Short Review ◽  
Flexible Substrates ◽  
School Students ◽  
Diverse Range ◽  
Lab On Chip ◽  
Resource Limited ◽  
Plastic Materials ◽  
On Chip

Flexible microfluidic devices are currently in demand because they can be mass-produced in resource-limited settings using simple and inexpensive fabrication tools. Finding new ways to fabricate microfluidic platforms on flexible substrates has been a hot area. Integration of customized detection tools for different lab-on-chip applications has made this area challenging. Significant advancements have occurred in the area over the last decade; therefore, there is a need to review such interesting fabrication tools employed on flexible substrates, such as paper and plastics. In this short review, we review individual fabrication tools and their combinations that have been used to develop such platforms in the past five years. These tools are not only simple and low-cost but also require minimal skills for their operation. Moreover, key examples of plastic-based flexible substrates are also presented, because a diverse range of plastic materials have prevailed recently for a variety of lab-on-chip applications. This review should attract audience of various levels, i.e., from hobbyists to scientists, and from high school students to postdoctoral researchers, to produce their own flexible devices in their own settings.

Visible-Light-Promoted Asymmetric Catalysis by Chiral Complexes of First-Row Transition Metals

Synthesis ◽  
2020 ◽  
Author(s):  
Yanjun Li ◽  
Ziqi Ye ◽  
Jiaxin Cai ◽  
Lei Gong
Keyword(s):  
Transition Metals ◽  
Visible Light ◽  
Asymmetric Catalysis ◽  
Functional Group ◽  
Short Review ◽  
Chiral Complexes ◽  
Diverse Range ◽  
Mild Conditions ◽  
Nickel Cobalt ◽  
Visible Light Driven

This short review presents an overview of visible-light-driven asymmetric catalysis by chiral complexes of first-row transition metals. The processes described here include dual catalysis by a chiral complex of copper, nickel, cobalt or chromium and an additional photoredox or energy-transfer catalyst, and bifunctional catalysis by a single chiral copper or nickel catalyst. These methods allow valuable transformations with high functional group compatibility. They provide stereoselective construction of carbon-carbon or carbon-heteroatom bonds under mild conditions, and produce a diverse range of previously unknown enantio-enriched compounds.

scholarly journals A Short Review on Polymeric Biomaterials as Additives for Lubricants

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1333
Author(s):  
Gobinda Karmakar ◽  
Koushik Dey ◽  
Pranab Ghosh ◽  
Brajendra K. Sharma ◽  
Sevim Z. Erhan
Keyword(s):  
Rice Bran Oil ◽  
Viscosity Index ◽  
Polymeric Materials ◽  
Gel Permeation Chromatography ◽  
Short Review ◽  
Viscosity Index Improver ◽  
Spectral Techniques ◽  
Molecular Weights ◽  
Petroleum Resources ◽  
Multifunctional Additives

With increasing environmental concerns and the depletion of petroleum resources, the development of lubricant additives from bioresources has attracted much attention recently. In this review, we reported a few polymers and polymer composites that are synthesized from vegetable oils (soybean oil, sunflower oil, rice bran oil, and castor oil) and used as multifunctional additives in the formulation of eco-friendly lubricant compositions. We mentioned the preparation of vegetable oil-based homo- and copolymers and their characterization by different spectral techniques (FTIR/NMR). The average molecular weights of the polymers are determined by gel permeation chromatography (GPC). Performance evaluations of the polymeric materials mainly as a viscosity index improver (VII), pour point depressant (PPD), and most importantly antifriction additives when blended with lubricating base oils are indicated. Standard ASTM methods have been applied to evaluate their performances. The findings have shown that all the additives discussed are non-toxic, biodegradable, and showed excellent performances compared to commercial petroleum-based additives.

scholarly journals Recent Advances in the Generation of Nitrilium Betaine 1,3-Dipoles

Synthesis ◽  
2021 ◽  
Author(s):  
Craig Jamieson ◽  
Keith Livingstone ◽  
Gemma Little
Keyword(s):  
Organic Chemistry ◽  
Recent Progress ◽  
Materials Science ◽  
Short Review ◽  
High Reactivity ◽  
Natural Product Synthesis ◽  
Hypervalent Iodine ◽  
Diverse Range ◽  
Nitrile Imines

AbstractNitrilium betaine 1,3-dipoles are ubiquitous reagents in organic chemistry, with applications ranging from natural product synthesis to materials science. Given the high reactivity of these zwitterionic motifs, they are invariably generated in situ from a suitable precursor, prior to use. This short review summarises the recent progress in the development of modern approaches towards the formation of these 1,3-dipoles, and their applications within a diverse range of fields.1 Introduction2 Nitrile Ylides2.1 2H-Azirine Rearrangement2.2 Addition of Nitriles to Carbenes3 Nitrile Imines3.1 2,5-Tetrazole Thermolysis3.2 2,5-Tetrazole Photolysis3.3 Diaryl Sydnone Photolysis4 Nitrile Oxides4.1 Hypervalent Iodine4.2 The Nitroso Radical4.3 Green Chemistry Approaches4.4 Other Approaches5 Conclusions

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