Water on polyethylene

Plot the shape of the contact line pinned to a defect using Eq. X-30 for water on polyethylene, stearic acid, and platinum. Assume that the upper cutoff length is 2 mm. How does the shape of the pinned contact line compare with your observations of raindrops on dirty windows ... 

Table 5.1 Effect of water on polyethylene glycol (PEG) content and molecular weight (MW) of nonylphenol 9 ethoxylate (NP9)...

Chang and Bonner (1975) measured retention volume data for water on polyethylene oxide) (PEO) at 343.55 K. 

Lipase from C. rugosa entrapped on polyethylene glycol Iso-octane-water (4/1) Olive oil hydrolysis 35 41.5 /xmol/(min g of support) 0.043% w/v 121... 

The most widely used hydrogels are based on polyethylene oxides (PEOs) dissolved at relatively low concentrations in water (typically 4 to 5%). Modest radiation exposure (less than 10 kGy) is needed to form fhe gel. Gels as thick as 2 mm (80 mils) are being produced. 

Mercury is particularly liable to loss on polyethylene. The loss of mercury at 0.05 ppm concentration (added as mercuric chloride) is such that in 4 h 95% is lost from Altered creek-water samples and 40% is lost from distilled-water samples, both stored in polyethylene. This loss rate is so rapid that some mechanism other than adsorption may be responsible one suggestion is that traces of reducing agents react with Hg(H) to form small amounts of Hg(I) that disproportionate to Hg(II) and Hg. The mercury formed is presumed to be lost by volatilization. 

One of the simplest methods of assessing such treatment of a polyethylene moulding is to immerse it in clean, cold water, withdraw it and then to observe the behaviour of the water on the surface over a given period of time. If the moulding was treated adequately, so that the surface was fully wettable, the aqueous surface film will be unbroken. Comparisons may be made by recording the times taken for the films of water to break up on bottles having different levels of treatment. 

The contact angle of water on non-crosslinked polyethylene decreased from 99.2° (unmodified LDPE) to... 

DuPont offers a family of biodegradable polymers based on polyethylene terephthalate (PET) technology known commercially as Biomax. Proprietary monomers are incorporated into the polymer, creating sites that are susceptible to hydrolysis. At elevated temperatures, the large polymer molecules are cleaved by moisture into smaller molecules, which are then consumed by naturally occurring microbes and converted to carbon dioxide, water and biomass. Biomax can be recycled, incinerated or landfilled, but is designed specifically for disposal by composting. 

In many laboratories that have access to a nuclear reactor, neutron activation is used for the chemical analysis of rocks, minerals, petroleum, biological tissues, alloys, etc., and the technique is well suited for the determination of the concentrations of trace elements in polymers. Neutron activation analysis was used by Given et al. (1) in their studies of water tree growth in polymeric insulation and by Wu and Chen (2) in their studies of dopant-polymer interactions in MoCl5-dcped polyacetylene films. In this work the principles of the method are described and the possibilities are illustrated by means of measurements carried out on polyethylene. 

Wettability. A comparison of contact angles for methylene iodide and pure water on natural films with the contact angles of the same liquids on known materials is shown in Table I. By the contact angle criterion, the natural films obviously resemble the two polar (but nonionic) polyamide materials much more closely than the high energy platinum or the non-polar polyethylene. There is a particularly close... 

As noted in the Introduction, the Cohn equation, (Eq. (1)), considers that log of protein solubility is a linear function of the cosolvent molarity. In reality [5,14], the above dependence is not linear. Fig. 1 presents some accurate experimental data regarding the aqueous solubility of lysozyme and shows that linearity occurs only in the dilute region (C3<0.5). Our Eq. (12) allows one to explain this behavior. Only the dilute region (c3<0.5) is considered because in this composition range the preferential binding parameter is proportional to the concentration of the cosolvent [58,64,69] and Eq. (12) involves this approximation. Eq. (12) reveals that the linearity or nonlinearity of In y2 versus cosolvent concentration depends on the water activity in the protein-free aqueous mixed solvent. Eq. (12) was used to examine the log protein solubility versus eosolvent molarity in water/protein/ polyethylene glycol (PEG) mixtures [42]. It was shown that there were almost linear behaviors for PEG 1000 and PEG... 

Preconcentration of T1 in the form of ion associate with rhodamine B on polyethylene powder was applied prior to the determination in tap water, dialysis fluids and alkali-metal salts [1]. 

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