Hybrid polymer-network gels built by both physical and covalent polymer crosslinking combine the advantages of both these crosslinking types: they exhibit high mechanical strength along with excellent fracture toughness and extensibility. If these materials are extensively deformed, their physical crosslinks can break such that strain energy is dissipated and irreversible fracturing is restrict...

A hydrogel is a water-insoluble three-dimensional polymer network that has the ability to absorb body fluids in biological environment. Such formed through chemical crosslinking mechanisms such as optical polymerization, enzymatic reactions and physical temperature pH dependent processes ionic crosslinking. Physical hydrogels are weak secondary force by covalent forces. Various polymers of natu...

The fabrication of hydrogel electrode materials via inkjet/extrusion printing, wet-spinning and physical crosslinking will be presented. Electrode characteristics such as conductivity, contact resistance, impedance and electrode connectivity will be discussed in detail.

The chemoreceptor molecules that mediate chemotactic responses in bacteria and archaea are physically clustered and operate as highly cooperative arrays. Few experimental approaches are able to investigate the structure-function organization of these chemoreceptor networks in living cells. This chapter describes chemical crosslinking methods that can be applied under normal physiological condit...

Biological tissues are viscoelastic, demonstrating a mixture of fluid and solid responses to mechanical strain. Whilst viscoelasticity is critical for native tissue function, it is rarely used as a design criterion in biomaterials science or tissue engineering. We propose that viscoelasticity may be tailored to specific levels through manipulation of the hydrogel type, or more specifically the ...

Mucoadhesive chitosan microspheres of amlodipine besylate were prepared for nasal administration with the aim of avoiding the first pass effect. A series of batches of microspheres were prepared by simple emulsification crosslinking method to optimize parameters like external phase (mixture of heavy and light liquid paraffin in the ratio of 1:1), stirring rate (1200 rpm), dioctyl sodium sulfosu...

The wet strength of handsheets subjected to dipping treatment by solutions such as glyoxal with Zn(NO3)2 as a catalyst, chitosan, and the crosslinking system of glyoxal and chitosan is studied in this paper. The crosslinking system achieved better wet strength performance than glyoxal or chitosan alone and slightly better than the sum of glyoxal and chitosan in the case of a curing temperature ...

The application of the microencapsulation technique in medicine and pharmacy has been extensively studied in recent years. The microencapsulation of small particles in polymeric, waxy or other kind of protective shells has become a well-established technology for coating and isolating various substances. The present paper presents the results obtained in a study concerning the influence of cros...