Mechanochemiluminescent hydrogels for real-time visualization of chemical bond scission

Quantitative and real-time characterization of mechanically induced bond scission events taken place in polymeric hydrogels is essential to uncover their fracture mechanics. Herein, a class of mechanochemiluminescent swelling hydrogels have been synthesized through a facile micellar copolymerization method using chemiluminescent bis(adamantyl)-1,2-dioxetane (Ad) as a crosslinker. This design and synthetic strategy ensure intense mechanochemiluminescence from Ad located in a hydrophobic network inside micelles. Moreover, the mechanochemiluminescent colors can be tailored from blue to red by mixing variant acceptors. Taking advantages of the transient nature of dioxetane chemiluminescence, the damage distribution and crack evolution of the hydrogels can be visualized and analyzed with high spatial and temporal resolution. The results demonstrate the strengths of the Ad mechanophore and micellar copolymerization method in the study of damage evolution and fracture mechanism of swelling hydrogels.

Biocompatible Tough Hydrogels via Micellar Copolymerization of NIPAM and Stearyl Acrylate: Synthesis and Characterization

Novel biocompatible tough hydrogels were prepared through free radical micellar polymerization of N-isopropylacrylamide (NIPAM) with ammonium persulphate (APS) as initiator, in which hydrophobic monomer stearyl acrylate (C18) underwent micellar polymerization in the presence of gelatin as emulsifier. FT-IR and DSC demonstrated the formation of co-polymer of NIPAM and C18. Swelling results indicated that hydrophobic polymer domains derived from C18 in aqueous medium acted as the physical crosslinking points by hydrophobic association. Uniaxial tensile test demonstrated the mechanical properties of hydrogels increased with increasing C18 and gelatin contents. The hydrogel exhibited low toxicity and promoted cell proliferation. The desirable toughness, low toxicity and the promoting effect of cell proliferation made the present hydrogels good candidates for tissue regeneration materials.

Hydrogels with high mechanical strength cross-linked by a rosin-based crosslinking agent

A novel type of DN hydrogel, prepared by micellar copolymerization of acrylamide and rosin-based crosslinking agent in a micellar solution of SDS. The hydrogels could form both chemical crosslinks and hydrophobic association crosslinked centers.

Synthesis and evaluation of β-cyclodextrin-functionalized hydrophobically associating polyacrylamide

Modified β-cyclodextrin and N-phenethyl-methacrylamide were utilized to react with acrylamide and acrylic acid to synthesize hydrophobically associating polyacrylamide (HMPAM) via photoinitiated free-radical micellar copolymerization.

Preparation of photodegradable polyacrylamide hydrogels via micellar copolymerization and determination of their phototunable elasticity and swelling behaviors

A photo-decomposable hydrophobic crosslinker was synthesized and utilized to obtain photo-tunable hydrogelsviafree radical micellar copolymerization.

Rheological behavior of hydrophobically modified polysulfobetaine methacrylate aqueous solution

Polysulfobetaine methacrylate (PSBMA) that was hydrophobically modified with methacrylic acid 2,3-epoxypropyl ester (GMA) was synthesized via micellar copolymerization method. Viscosity of the hydrophobically modified PSBMA solution was sensitive to added salt concentration.

Synthesis and Rheological Properties of Poly (AM-TBAM-NMMAD) Random-Block Copolymer

Poly (TBAM-AM-NMMAD) random-block copolymer were prepared by aqueous micellar copolymerization using AIBA (V50), ammonium persulfate (J) and sodium bisulfite (D) as initiator and SDS as surfactant in the mixture solvent of deionized water. The structure of Poly (TBAM-AM-NMMAD) was characterized by solid state13C-NMR and FTIR spectroscopy and the dynamic viscosity was measured by the NDJ-1 viscometer. The experimental results and analysis shows poly (AM-TBAM-NMMAD) random-block copolymer which had been endowed with high rheological properties was successfully synthesized by controlling the abundance of initiator based on the method of orthogonal experiment.

Preparation of Magnetic Fluids Based on Associated Polymers

This paper describes two methods of preparation of magnetic fluids based on associated polymers. The first method is ultrasonic (US) dispersing of magnetite microparticles (MP) in aqueous solutions of associated polymers such as hydrophobically modified polyacrylamides (HM PAAm) – terpolymers of acrylamide (AAm), sodium acrylate (SA) and N-dodecylacrylamide (DDAA). According to the second method the magnetic fluids were formed by addition of magnetic polymers, synthesized by means of a micellar copolymerization of AA, SA and DDAA in the presence of MP, into water. The investigation of the rheological properties has shown that magnetic fluids obtained can be reversibly transformed in physical gels in magnetic field (MF).