title: Multiphase adhesive coacervates inspired by the Sandcastle worm.
abstract: Water-borne, underwater adhesives were created by complex coacervation of synthetic copolyelectrolytes that mimic the proteins of the natural underwater adhesive of the sandcastle worm. To increase bond strengths, we created a second polymer network within cross-linked coacervate network by entrapping polyethylene glycol diacrylate (PEG-dA) monomers in the coacervate phase. Simultaneous polymerization of PEG-dA and cross-linking of the coacervate network resulted in maximum shear bond strengths of ∼1.2 MPa. Approximately 40% of the entrapped PEG-dA polymerized based on attenuated total reflectance-Fourier transform infrared spectroscopy. The monomer-filled coacervate had complex flow behavior, thickening at low shear rates and then thinning suddenly with a 16-fold drop in viscosity at shear rates near 6 s(-1). The microscale structure of the complex coacervates resembled a three-dimensional porous network of interconnected tubules. The sharp shear thinning behavior is conceptualized as a structural reorganization between the interspersed phases of the complex coacervate. The bond strength and complex fluid behavior of the monomer-filled coacervates have important implications for medical applications of the adhesives.
authors.forename: Sarbjit
authors.initials: S
authors.lastname: Kaur
authors.forename: G Mahika
authors.initials: GM
authors.lastname: Weerasekare
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Stewart
mesh_terms: D000269:Adhesives / Q000737:chemistry / Q000378:metabolism; D001672:Biocompatible Materials / Q000737:chemistry* / Q000378:metabolism*; D015801:Helminth Proteins / Q000737:chemistry* / Q000378:metabolism*; D046911:Macromolecular Substances / Q000737:chemistry* / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000269:Adhesives; D001672:Biocompatible Materials; D015801:Helminth Proteins; D046911:Macromolecular Substances; D011092:Polyethylene Glycols