Search results for "Poly ethylene"
showing 4 items of 14 documents
Interactions between proteins and poly(ethylene-glycol) investigated using molecular dynamics simulations
2017
Poly(ethylene-glycol) (PEG) is a polymer used to coat therapeutic preparations, like drugs or drug nanocarriers, and improve their efficacy. This effect is probably due to a reduction of the interactions of the coated species with the host organism. Nevertheless, experiments show that PEGylated materials do interact with the surrounding biological milieu, and in particular with blood proteins. Here, we use atomistic molecular dynamics simulations to characterize the interactions between the polymer and several blood proteins. In these simulations, the proteins are immersed in a mixture of PEG and water molecules. We observe how PEG distributes around the protein surface and measure PEG-prot…
Determining the selective impregnation of waterlogged archaeological woods with poly(ethylene) glycols mixtures by differential scanning calorimetry
2012
The differential scanning calorimetry (DSC) technique was demonstrated to be a reliable and fast tool for the investigation of the selective impregnation of archaeological woods with poly(ethylene) glycols (PEGs) mixtures. To this aim, waterlogged archaeological woods were impregnated by using aqueous mixtures of PEG 4000 and PEG 400 as well as mixtures of these polymers in the melt state. The efficiency of the treatments was also estimated by determining the total consolidant content entrapped into the cavities of degraded wood by means of DSC and thermogravimetry.
Thermodynamics of Aqueous Poly(ethylene oxide)−Poly(propylene oxide)−Poly(ethylene oxide)/Surfactant Mixtures. Effect of the Copolymer Molecular Weig…
2004
A calorimetric study was performed to focus attention on the interactions between copolymers and anionic surfactants in aqueous solutions. Three aspects were analyzed: (1) the hydrophobicity of the surfactant, (2) the change of the copolymer molecular weight, and (3) the nature of the hydrophilicity of the copolymer. To this purpose, the family of sodium alkanoates (sodium octanoate through sodium dodecanoate) and the triblock copolymers EO76PO 29EO76 (F68), EO103PO39EO 103 and EO132PO50EO132 were investigated. Comparing F68 and EO13PO30EO13 (L64), previously studied by us, provided information on the effect of the copolymer hydrophilicity. The experimental data were analyzed by means of a …
Aqueous Laponite Clay Dispersions in the Presence of Poly(ethylene oxide) or Poly(propylene oxide) Oligomers and their Triblock Copolymers
2008
The effect of polyethylene oxide (PEO) or polypropylene oxide (PPO) oligomers of various molecular weight (Mw) as well as of triblock copolymers, based on PEO and PPO blocks, on aqueous laponite RD suspensions was studied with small-angle neutron scattering (SANS). The radius of gyration (RG) increases for low Mw whereas the opposite occurs for larger Mw. This behavior is explained on the-basis that an effective RG is given by two contributions: (1) the size of the particles coated with the polymer and (2) the interactions between the laponite RD particles which are attractive for small and repulsive for large polymers. The SANS curves in the whole Q-range are well described by a model of n…