Chapter 5
Polymer Gels
Abstract The cross-linking of long-chain polymeric gelators has been shown to be
an effective driving force for the formation of polymer gels. In this chapter, various
polymer gels are discussed according to the interaction species of the cross-linking
between the gelators. The interactions include hydrogen bonding, metal–organic
coordination and dynamic covalent bonding. Prior to discussing these interactions,
several traditional polymer gels are introduced such as silicone-based gels and
polymer hydrogels. The thermodynamic aspects relating to the swelling of polymer
gels upon exposure to a liquid are described in detail. By analysing the macroscopic
degree of swelling of a polymer gel, the microscopic cross-linking between polymer
chains can be probed quantitatively. The formation of the polymer gels driven by
different interactions is presented by illustrating the correlation between the properties and driving forces. Following the gel systems comprising individual interaction species, strategies to combine polymer and low molecular weight gels are
presented. The emerging hybrid materials are promising to integrate the advantages
of both polymer and low molecular weight gels.
Keywords Polymer gels Á Cross-linking Á Swelling Á Hydrogen bonding
Metal–organic coordination Á Dynamic covalent bonding Á Hybrid gels
5.1 Introduction to Polymer Gels
Polymer gels are three-dimensional (3D) molecular networks formed by the light
cross-linking of long-chain polymeric gelators. Within the 3D networks, liquids
such as water and organic solvents are encapsulated. Similar to low molecular
weight gelators, the cross-linking of polymeric gelators can also be achieved via
either non-covalent or covalent interactions. Compared with non-covalently
cross-linked polymers, 3D molecular networks with covalent cross-linking are
relatively robust and, however, sometimes less responsive to external stimuli.
Ya Hu and Jianyong Zhang contributed together to this chapter.
© Springer Nature Singapore Pte Ltd. 2018
J. Zhang et al., Gel Chemistry, Lecture Notes in Chemistry 96,
https://doi.org/10.1007/978-981-10-6881-2_5
153
Polymer Gels
Abstract The cross-linking of long-chain polymeric gelators has been shown to be
an effective driving force for the formation of polymer gels. In this chapter, various
polymer gels are discussed according to the interaction species of the cross-linking
between the gelators. The interactions include hydrogen bonding, metal–organic
coordination and dynamic covalent bonding. Prior to discussing these interactions,
several traditional polymer gels are introduced such as silicone-based gels and
polymer hydrogels. The thermodynamic aspects relating to the swelling of polymer
gels upon exposure to a liquid are described in detail. By analysing the macroscopic
degree of swelling of a polymer gel, the microscopic cross-linking between polymer
chains can be probed quantitatively. The formation of the polymer gels driven by
different interactions is presented by illustrating the correlation between the properties and driving forces. Following the gel systems comprising individual interaction species, strategies to combine polymer and low molecular weight gels are
presented. The emerging hybrid materials are promising to integrate the advantages
of both polymer and low molecular weight gels.
Keywords Polymer gels Á Cross-linking Á Swelling Á Hydrogen bonding
Metal–organic coordination Á Dynamic covalent bonding Á Hybrid gels
5.1 Introduction to Polymer Gels
Polymer gels are three-dimensional (3D) molecular networks formed by the light
cross-linking of long-chain polymeric gelators. Within the 3D networks, liquids
such as water and organic solvents are encapsulated. Similar to low molecular
weight gelators, the cross-linking of polymeric gelators can also be achieved via
either non-covalent or covalent interactions. Compared with non-covalently
cross-linked polymers, 3D molecular networks with covalent cross-linking are
relatively robust and, however, sometimes less responsive to external stimuli.
Ya Hu and Jianyong Zhang contributed together to this chapter.
© Springer Nature Singapore Pte Ltd. 2018
J. Zhang et al., Gel Chemistry, Lecture Notes in Chemistry 96,
https://doi.org/10.1007/978-981-10-6881-2_5
153