A method is presented to prevent microbial adhesion to solid surfaces exploiting the unique properties of polymer brushes. Polyacrylamide (PAAm) brushes were grown from silicon wafers by atom transfer radical polymerization (ATRP) using a three-step reaction procedure consisting of immobilization of a coupling agent γ-aminopropyltriethoxysilane, anchoring of an ATRP initiator 4-(chloromethyl)benzoyl chloride, and controlled radical polymerization of acrylamide. The surfaces were characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, ellipsometry, and contact-angle measurements. The calculated grafting density pointed to the presence of a dense and homogeneous polymer brush. Initial deposition rates, adhesion after 4 h, and detachment of two bacterial strains (Staphylococcus aureus ATCC 12600 and Streptococcus salivarius GB 24/9) and one yeast strain (Candida albicans GB 1/2) to both PAAm-coated and untreated silicon surfaces were investigated in a parallel plate flow chamber. A high reduction (70−92%) in microbial adhesion to the surface-grafted PAAm brush was observed, as compared with untreated silicon surfaces. Application of the proposed grafting method to silicone rubbers may offer great potential to prevent biomaterials-centered infection of implants.

The present paper gives an account of the results of a systematic investigation on the fungicidal It is shown that among these compounds one structural Within this type the influence on theThe toxicity of organo-tin compounds towards some other organisms is mentioned briefly. The final section deals with possibilities for practical applications of organo-tin compounds From the results of laboratory tests the preservation properties of organo-tin compounds.type in particular exhibits a very high fungicidal activity.activity of the nature of the various groups linked to tin has been investigated.as a consequence of their biocidal properties. of wood seems the most promising possibility.

The preparation, according to t he slightly modified procedure of Finholt et al., of the following organo-tin hydrides is described: tri ethyltin hydride, tri-n-propyltin hydride, tri-n-butyltin hydride, triphenyltin hydride, di-n-propyltin dihydride, di-n-butyltin dihydride, diphenyltin dihydride and n-butyltin trihydride.In addition, the preparation of the intermediate n-butyltin trichloride is described.

The reversible manipulation of the helix screw sense in surface-grafted poly(β-phenethyl-L-aspartate) (PPELA) films by means of external stimuli was investigated. Ringopening polymerization of β-phenethyl-L-aspartate N-carboxyanhydride initiated from primary amino-functionalized silicon and quartz substrates results in surfacegrafted PPELA films in which the end-grafted polypeptide chains have a right-handed R-helical conformation. Upon annealing of the film at 150 °C for 30 min, a helix screw sense inversion takes place and the grafted chains adopt a left-handed π-helical conformation. In the solid state, this left-handed π-helical form is completely stable and cannot be changed by reheating and/or cooling. Upon immersion of the annealed grafted film in chloroform or other helicogenic solvents, the grafted polypeptide chains completely revert to their original right-handed R-helical form. Successive annealing and solvent treatment steps show that this helix sense inversion cycle can be repeated many times.