Polylactic acid is proving to be a viable alternative to petrochemical-based plastics for many applications It is produced from renewable resources and is biodegradable, decomposing to give H2O, CO2, and humus, the black material in soil In addition, it has unique physical properties that make it useful in diverse applications including paper coating, fibers, films, and packaging (see Figure)

Polylactic Acid Technology

Nanoparticle interaction with plasma proteins as it relates to particle biodistribution, biocompatibility and therapeutic efficacy.

Morphology evolution via self-organization and lateral and vertical diffusion in polymer:fullerene solar cell blends

Morphology evolution via self-organization and lateral and vertical diffusion in polymer:fullerene solar cell blends.

https://www.zora.uzh.ch/id/eprint/44154/1/Rabe1.pdf

Understanding protein adsorption phenomena at solid surfaces

Protein Nanoparticle Interactions: Opportunities and Challenges Morteza Mahmoudi,* Iseult Lynch, Mohammad Reza Ejtehadi, Marco P. Monopoli, Francesca Baldelli Bombelli, and Sophie Laurent National Cell Bank, Pasteur Institute of Iran, Tehran, Iran Nanotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran School of Chemistry and Chemical Biology & Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland Department of Physics, Sharif University of Technology, Tehran, Iran School of Pharmacy, UEA, Norwich Research Park, Norwich,U.K. Department of General, Organic, and Biomedical Chemistry, NMR and Molecular Imaging Laboratory, University of Mons, Avenue Maistriau 19, B-7000 Mons, Belgium

Protein-nanoparticle interactions: opportunities and challenges.

Optical Probes of the Glass Transition in Thin Polymer Films

We report measurements of the onset temperature of rejuvenation, T_{onset}, and the fictive temperature, T_{f}, for ultrathin stable polystyrene with thicknesses from 10 to 50 nm prepared by physical vapor deposition. We also measure the T_{g} of these glasses on the first cooling after rejuvenation as well as the density anomaly of the as-deposited material. Both the T_{g} in rejuvenated films and the T_{onset} in stable films decrease with decreasing film thickness. The T_{f} value increases for decreasing film thickness. The density increase typical of stable glasses also decreases with decreasing film thickness. Collectively, the results are consistent with a decrease in apparent T_{g} due to the existence of a mobile surface layer, as well as a decrease in the film stability as the thickness is decreased. The results provide the first self-consistent set of measurements of stability in ultrathin films of stable glass.

Film Thickness Dependent Stability and Glass Transition Temperature of Polymer Films Produced by Physical Vapor Deposition.

Micrococcal Activity Assays • When biologically active, lysozyme exposed to Micrococcus lysodeikticus causes the micrococcal cells to burst, increasing the amount of cell fragments and decreasing the amount of intact cells. • At 450nm intact micrococcal cells and cell fragments scatter light differently, and changes in optical density can be correlated to changes in the concentration of intact cells and calibrated to determine the amount of active lysozyme in a sample. • The activity of surface adsorbed lysozyme with and without lactoferrin was assessed using previously established micrococcal activity assays.4,6

The effect of lactoferrin on lysozyme deposition and activity on silicone hydrogel contact lenses

Man ydynamica lpropertie so fpolymers ,includin gsegmenta lrelaxation an dchai ndiffusion ,exhibi tanomalie si nthin-fil msamples .W eexten dth estudie sof thin-fil mdynamic st oth ecas eo fsemicrystallin epolymer san dpresen ta stud yo fthe crysta lgrowt hrat efo rthi nfilm so fpoly(ethylen eoxide) .W euse doptica lmicroscopy an dquart zcrysta lmicrobalanc etechnique st ocharacteriz eth ekinetic so fcrystalliza- tio nfo rfilm swit hthicknesse sfro m4 0t o100 0n mfo ra rang eo ftemperature snea rthe meltin gpoint .A remarkabl eslowin gdow no fth ecrysta lgrowt hi sobserve da tall temperature sstudie dfo rfilm swit ha thicknes so fles stha n;10 0nm .Th eresult scan b euse dt osugges treduction so fth emobilit yo fchain sa tth ecrystal/amorphous interface . ©200 1Joh nWile y& Sons ,Inc .J Poly mSc iPar tB :Poly mPhy s39 :2615-2621 ,2001

Crysta lGrowt hRat ei nUltrathi nFilm sof Poly(ethylen eoxide)

Freestanding thin polymer films with high molecular weights exhibit an anomalous decrease in the glass-transition temperature with film thickness. Specifically, in such materials, the measured glass-transition temperature evolves in an affine way with the film thickness, with a slope that weakly depends on the molecular weight. De Gennes proposed a sliding mechanism as the hypothetical dominant relaxation process in these systems, where stress kinks could propagate in a reptation-like fashion through so-called bridges, i.e. from one free interface to the other along the backbones of polymer macromolecules. Here, by considering the exact statistics of finite-sized random walks within a confined box, we investigate in details the bridge hypothesis. We show that the sliding mechanism cannot reproduce the basic features appearing in the experiments, and we exhibit the fundamental reasons behind such a fact. 

/pdf/on-the-bridge-hypothesis-in-the-glass-transition-of-r2ml4s1u.pdf

James A. Forrest

Papers

Optical Probes of the Glass Transition in Thin Polymer Films

Film Thickness Dependent Stability and Glass Transition Temperature of Polymer Films Produced by Physical Vapor Deposition.

The effect of lactoferrin on lysozyme deposition and activity on silicone hydrogel contact lenses

Crysta lGrowt hRat ei nUltrathi nFilm sof Poly(ethylen eoxide)

On the bridge hypothesis in the glass transition of freestanding polymer films