Surfactant controlled zwitterionic cellulose nanofibril dispersions
Vincenzo Calabrese1, Marcelo A da Silva, Julien Schmitt
1Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK. k.edler@bath.ac.uk.
Soft Matter
|August 16, 2018
Summary
Zwitterionic cellulose nanofibrils (ZCNFs) were stabilized using surfactants. Anionic surfactants individualized ZCNF fibrils, while cationic surfactants caused aggregation, demonstrating tunable dispersion stability.
Area of Science:
- Materials Science
- Nanotechnology
- Surface Chemistry
Background:
- Cellulose nanofibrils (CNFs) are promising nanomaterials with diverse applications.
- Controlling the stability and dispersion of CNFs is crucial for their effective utilization.
- Zwitterionic modification offers a route to tailor CNF properties.
Purpose of the Study:
- To synthesize zwitterionic cellulose nanofibrils (ZCNFs).
- To investigate the effect of surfactants on ZCNF dispersion stability.
- To understand the mechanisms governing ZCNF aggregation and stabilization.
Main Methods:
- Synthesis of ZCNFs by grafting glycidyltrimethylammonium chloride onto oxidized CNFs.
- Characterization using transmission electron microscopy, rheology, and small-angle neutron scattering.
- Treatment of ZCNF dispersions with anionic (sodium dodecyl sulfate) and cationic (dodecyltrimethylammonium bromide) surfactants.
Main Results:
- ZCNFs exhibited a fibril-bundle structure with aggregation at neutral pH.
- Anionic surfactant (SDS) addition led to individualized fibrils via electrostatic stabilization.
- Cationic surfactant (DTAB) addition caused charge neutralization and pronounced flocculation.
Conclusions:
- Surfactants can effectively tune the stability of zwitterionic cellulose nanofibril dispersions.
- Electrostatic stabilization with anionic surfactants promotes fibril individualization.
- Charge neutralization with cationic surfactants leads to aggregation, highlighting the importance of surface charge in dispersion behavior.
Related Concept Videos
00:54Distribution and Dispersion
25.4K
To understand intra-specific interactions in populations, scientists measure the spatial arrangement of species individuals. This geographic arrangement is known as the species distribution or dispersion. Highly territorial species exhibit a uniform distribution pattern, in which individuals are spaced at relatively equal distances from one another. Species that are highly tied to particular resources, such as food or shelter, tend to concentrate around those resources, and thus exhibit a...
25.4K
01:15Cellulose and Pectic Polysaccharides
4.9K
Every plant cell has a cell wall that protects the cell, provides structural support, and gives the cell shape. Cellulose, the main structural component of the plant cell wall, makes up over 30% of plant matter. It is the most abundant organic compound on earth. Cellulose is an unbranched polysaccharide composed of linear chains of glucose molecules linked by β (1→4) glycosidic bonds.
As a cell matures, its cell wall specializes according to its type. For example, the...
As a cell matures, its cell wall specializes according to its type. For example, the...
4.9K
01:21Control System Problem
437
In an open-loop system, such as a basic thermostat, the poles of the transfer function influence the system's response but do not determine its stability. However, when feedback is introduced to form a closed-loop system, such as an advanced thermostat that adjusts heating based on room temperature, stability is governed by the new poles of the closed-loop transfer function.
When forming a closed-loop system, issues can arise if the poles cross into the unstable region, leading to potential...
When forming a closed-loop system, issues can arise if the poles cross into the unstable region, leading to potential...
437
02:33Combinatorial Gene Control
9.7K
Combinatorial gene control is the synergistic action of several transcriptional factors to regulate the expression of a single gene. The absence of one or more of these factors may lead to a significant difference in the level of gene expression or repression.
The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene...
The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene...
9.7K
01:23Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
475
Biopharmaceutical studies constitute a vital field aiming to enhance drug delivery methods and refine therapeutic approaches, drawing upon diverse interdisciplinary knowledge. In research methodologies, the choice between controlled and non-controlled studies significantly influences the study's reliability and accuracy.
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
475
01:10Control Systems
1.9K
Control systems are everywhere in contemporary society, influencing diverse applications from aerospace to automated manufacturing. These systems can be found naturally within biological processes, such as blood sugar regulation and heart rate adjustment in response to stress, as well as in man-made systems like elevators and automated vehicles. A control system is essentially a network of subsystems and processes that collaboratively convert specific inputs into desired outputs.
At the heart...
At the heart...
1.9K