Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Exploring molecular recognition pathways in one- and two-component gels formed by dendritic lysine-based gelators
AU - Hardy, John G.
AU - Hirst, Andrew R.
AU - Smith, David K.
PY - 2012
Y1 - 2012
N2 - This paper provides an integrated overview of the factors which control gelation in a family of dendritic gelators based on lysine building blocks. In particular, we establish that higher generation systems are more effective gelators, amide linkages in the dendron are better than carbamates, and long alkyl chain surface groups and a carboxylic acid at the focal point enhance gelation. The gels are best formed in relatively low polarity solvents with no hydrogen bond donor ability and limited hydrogen bond acceptor capacity. The dendrons with acid groups at the focal point can form two component gels with diaminododecane, and in this case, it is the lower generation dendrons which can avoid steric hindrance and form more effective gels. The stereochemistry of lysine is crucial in self-assembly, with opposite enantiomers disrupting each other's molecular recognition pathways. For the two-component system, stoichiometry is key, if too much diamine is present, dendron-stabilised microcrystals of the diamine begin to form. Interestingly, gelation still occurs in this case, and the systems with amides/alkyl chains are more effective gels, as a consequence of enhanced dendron-dendron intermolecular interactions allowing the microcrystals to form an interconnected network.
AB - This paper provides an integrated overview of the factors which control gelation in a family of dendritic gelators based on lysine building blocks. In particular, we establish that higher generation systems are more effective gelators, amide linkages in the dendron are better than carbamates, and long alkyl chain surface groups and a carboxylic acid at the focal point enhance gelation. The gels are best formed in relatively low polarity solvents with no hydrogen bond donor ability and limited hydrogen bond acceptor capacity. The dendrons with acid groups at the focal point can form two component gels with diaminododecane, and in this case, it is the lower generation dendrons which can avoid steric hindrance and form more effective gels. The stereochemistry of lysine is crucial in self-assembly, with opposite enantiomers disrupting each other's molecular recognition pathways. For the two-component system, stoichiometry is key, if too much diamine is present, dendron-stabilised microcrystals of the diamine begin to form. Interestingly, gelation still occurs in this case, and the systems with amides/alkyl chains are more effective gels, as a consequence of enhanced dendron-dendron intermolecular interactions allowing the microcrystals to form an interconnected network.
KW - ACID-TERMINATED POLYDIMETHYLSILOXANES
KW - PHASE MATERIALS
KW - WEIGHT GELATORS
KW - SUPRAMOLECULAR ASSOCIATION
KW - PEPTIDIC DENDRIMERS
KW - SELF-ORGANIZATION
KW - ONE-COMPONENT
KW - GELATION
KW - ORGANOGELATORS
KW - SOLVENT
KW - Chemistry(all)
KW - Materials Chemistry
KW - Polymers and Plastics
U2 - 10.1039/c2sm25129a
DO - 10.1039/c2sm25129a
M3 - Journal article
VL - 8
SP - 3399
EP - 3406
JO - Soft Matter
JF - Soft Matter
SN - 1744-683X
IS - 12
ER -