مجال
التميز
|
تميز دراسي و بحثي
|
|
|
البحوث المنشورة
|
|
البحث (1):
|
|
عنوان البحث:
|
An Addressable Packing Parameter
Approach For Reversibly Tuning The Assembly Of Oligo(Aniline)-Based
Supra-Amphiphiles†
|
رابط إلى البحث:
|
Click here
|
تاريخ النشر:
|
21/05/2018
|
موجز عن البحث:
|
We present a newly developed approach to
non-covalently address the packing parameter of an electroactive amphiphile.
The pH-responsive reversible switching of a tetra(aniline)-based cationic
amphiphile, TANI-pentyl trimethylammonium bromide (TANI-PTAB),
between self-assembled vesicles and nanowires by acid/base chemistry in
aqueous solution is used to exemplify this approach. Trifluoroacetic acid (TFA)
was selected as a prototypical acid to form emeraldine salt (ES) state (TANI(TFA)2-PTAB)
vesicles for this new class of small-molecule supramolecular amphiphiles.
UV-vis-NIR spectroscopy, transmission electron microscopy (TEM), tapping-mode
atomic force microscopy (AFM), and fluorescence spectroscopy were used to
investigate the reversible structural transformation from vesicles to
nanowires. We show that utilising different protonic acid-dopants for TANI-PTAB can
regulate the packing parameter, and thus the final self-assembled structures,
in a predictable fashion. We envisage potential application of this concept
as smart and switchable delivery systems.
|
|
|
البحث (2):
|
|
عنوان البحث:
|
Electroactive Amphiphiles for
Addressable Supramolecular Nanostructures
|
رابط إلى البحث:
|
Click here
|
تاريخ النشر:
|
31/05/2018
|
موجز عن البحث:
|
In this focus review we aim to highlight an
exciting class of materials, electroactive amphiphiles (EAAs). This class of
functional amphiphilic molecules has been the subject of sporadic
investigations over the last few decades, but little attempt has been made to
date to gather or organise these investigations into a logical fashion. Here
we attempted to gather the most important contributions, provide a framework
in which to discuss them, and, more importantly, point towards the areas
where we believe these EAAs will contribute to solving wider scientific
problems and open new opportunities. Our discussions cover materials based on
low molecular weight ferrocenes, viologens and anilines, as well as examples
of polymeric and supramolecular EAAs. With the advances of modern analytical
techniques and new tools for modelling and understanding optoelectronic
properties, we believe that this area of research is ready for further
exploration and exploitation.
|
|
|
المؤتمرات العلمية:
|
|
المؤتمر (1):
|
|
عنوان المؤتمر:
|
M4 Colloids Symposium
|
تاريخ الإنعقاد:
|
07/02/2015
|
مكان
الإنعقاد:
|
Bristol,
UK
|
طبيعة المشاركة:
|
Poster
presentation
|
عنوان المشاركة:
|
Towards Aqueous Self-Assembly of
Electroactive Oligo(aniline)s
|
ملخص المشاركة:
|
The conducting polymer poly(aniline)
(PANI) has received much attention due to its ease of synthesis and its
electrochemical and optical properties. Its unique properties are due to the
presence of a conjugated π-electron system [1-2]. However, PANI lacks
solubility in most common solvents, which limits its applications. Therefore
oligo(aniline)s are identified as ideal replacement, as the oligomers have
the same desirable properties of PANI as well as good solubility and
processability.
Keeping new applications in
mind, one of the important problems facing conducting polymers is the lack of
biocompatibility and biodegradability. A potential solution to this problem
is the introduction of biocompatible moieties. Hydrophilic polyethylene
glycol (PEG) is an attractive candidate because of its biocompatibility,
biodegradability, and wide medical application [3]. Block-like structures
containing oligo(aniline)s terminated with PEG chains can potentially solve
the mentioned problems and yield attractive properties for biomedical and
electrochemical applications [4].
In this project we aim to
synthesis two types of oligo(aniline)s , phenyl/amine end-capped
tetra(aniline), PH/NH2 TANI, and amine/amine end-capped
tetra(aniline), NH2/NH2 TANI. Once prepared, we aim to
functionalize these oligomers with short ethylene glycol chains (Figure 1)
using different coupling strategies. 1H NMR, UV-vis spectroscopy,
mass spectrometry and FT-IR spectroscopy characterization of the synthesized
block-like structures will be presented, as well as initial studies on
self-assembly in aqueous environments. The effect of dopants on the
electroactivity and self-assembly of the materials will also be discussed.
TANI-PEG
PEG-TANI-PEG
Figure 1: chemical structures of
TANI-PEG and PEG-TANI-PEG
|
|
|
المؤتمر (2):
|
|
عنوان المؤتمر:
|
Nanoscience:
A Celebration
|
تاريخ الإنعقاد:
|
23/05/2017
|
مكان
الإنعقاد:
|
Cardiff,
UK
|
طبيعة المشاركة:
|
Poster
presentation
|
عنوان المشاركة:
|
Synthesis And Self-Assembly Of
An Electroactive Bola-Amphiphile
|
ملخص المشاركة:
|
The conducting polymer poly(aniline) (PANI)
has received much attention due to its ease of synthesis and its
electrochemical and optical properties. Its unique properties are due to the
presence of a conjugated π-electron system [1-2]. However, PANI lacks
solubility in most common solvents, which limits its applications. Therefore
oligo(aniline)s are identified as ideal replacement, as the oligomers have
the same desirable properties of PANI as well as good solubility and
processability. Keeping new applications in mind, one of the important
problems facing conducting polymers is the lack of solubility and
processability. Recently, TANI has been functionalised with hydrophilic
moieties to form water-soluble amphiphiles, which are more interesting
materials in terms of exploring properties and applications [4]. In our
previous work, we synthesised and assembled the first TANI-based cationic
amphiphile, (TANI-PTAB), into nanowires. This assembly was driven by factors
such as the hydrophobic effect, with structure-directing hydrogen bonding and
π-π stacking interactions proposed to occur between TANI molecules [5]. Based
on the previous work, we designed and synthesised a new cationic
bola-amphiphile bearing the same chemical moieties of interest. We also
investigated the self-assembly behaviour in aqueous solution. The effect of
dopants on the electroactivity and self-assembly of the materials will also
be discussed.
|
|
|
المؤتمر (3):
|
|
عنوان المؤتمر:
|
McBain
Medal 2017: Watching Colloids Work
|
تاريخ الإنعقاد:
|
12/12/2017
|
مكان
الإنعقاد:
|
London.UK
|
طبيعة المشاركة:
|
Poster
presentation
|
عنوان المشاركة:
|
Self-Assembled Nanostructures Of
Electroactive Bola-Amphiphiles Based On Oligo(Aniline)s
|
ملخص المشاركة:
|
Poly(aniline), PANI, is one of the most
well-known and studied conducting polymers owing to its ease of synthesis and
attractive optoelectronic properties. However, PANI has low solubility, and
poor processability limits its application. 1 Therefore, oligo(aniline)s are
identified as an ideal replacement, as the oligomers have the same desirable
redox properties as PANI, 2 as well as good solubility and tuneable chemical
structure. 3 Tetra(aniline), the shortest oligo(aniline), is not soluble in
aqueous media. The introduction of flexible, solubilising moieties can
potentially improve the solubility and applicability. 4 Block-like structures
comprising oligo(aniline)s terminated with soluble moieties such as cationic
surfactants is one such route. A single-tailed amphiphile EB Ph/NH2
TANI-C6NMe3 +Br- (TANI-S) has been prepared in our group, 5 and exhibited the
formation of self-assembled wirelike nanostructures. To further explore the
behaviour of amphiphilic oligo(aniline)s, a TANI-based bola-amphiphile (i.e.,
TANI functionalised with two alkyltrimethylammonium head groups) was designed
for comparison with TANI-S. Successful synthesis of the electroactive
bola-amphiphile EB NH2/NH2 TANI-(C6NMe3 +Br- )2 (TANI-B) was confirmed using
different characterization techniques including 1H, 13CNMR spectroscopy and
accurate mass spectrometry. Results from investigations into the formation of
self-assembled structures, and their tunability and addressability will be
presented.
|