Polyethylene membranes

Hoechst Celanese Corp. Tonen Corp. Asahi Chemical Industries Mitsubishi Ube Industries Ltd. Pall RAI Celgard membranes made of polypropylene, polyethylene, and combinations Setela membranes made of polyethylene HiPore membranes made of polyethylene Exepol membranes made of polyethylene Polypropylene membranes Polyethylene membranes... 

BP3, OC, EHMC, EHS, HMS, OD-PABA, 4-MBC, BM-DBM, IAMC, EHT, DBT BP3, 4-MBC, EHMC, OC, OD-PABA, 4HB, 4DHB, BP1 PMALE with low density polyethylene membranes PT E with in-cell purification with aluminum oxide... 

Sabaliunas, D. and Sodergren, A. 1996, Uptake of organochlorine pesticides by solvent-filled cellulose and polyethylene membranes. Ecotox. Environ. Safe. 35 150-155. 

Booij, K. Hofmans, H.E. Fischer, C.V. van Weerlee, E.M. 2003, Temperature-dependent uptake rates of nonpolar organic compounds by semipermeable membrane devices and low-density polyethylene membranes.Ewiran. Sci. Technol. 37 361-366. 

Wang, R., Okajima, T., Kitamura, R, and Ohsaka, T., A novel amperometric O2 gas sensor based on supported room-temperature ionic liquid porous polyethylene membrane-coated electrodes, Electroanalysis, 16, 66-72, 2004. 

P 18.8 Evaluating the Effectiveness of a Polyethylene Membrane for Retaining Organic Pollutants in a Relatively Dilute Wastewater... 

FIGURE 3.3 Examples of passive samplers affected by deposition of suspended particulate matter and biofouling (a) silicone strip sampler, (b) nonpolar version of the Chemcatcher, (c) MESCO sampler fitted with a cellulose membrane, and (d) MESCO sampler fitted with polyethylene membrane (front) and SPMD (back). 

Ecoscope Hexane (organics) chelating resin (metals) Polyethylene membrane (organics), porous membrane (metals) Hydrophobic organic compounds, heavy metals Qualitative screening 2-4 weeks Direct injection of solvent or after concentration or extraction with acid 59... 

Carls, M.G., L.G. Holland, J.W. Short, R.A. Heintz, and S.D. Rice. 2004. Monitoring polynuclear aromatic hydrocarbons in aqueous environments with passive low-density polyethylene membrane devices. Environ Toxicol. Chem. 23 1416-1424. 

Investigation of Polyethylene Membranes as Potential Sample Support for Linking SDS-PAGE with MALDI-TOF MS for the Mass Measurement of Proteins... 

Five millimeter diameter disks of a porous polyethylene membrane, used as a window material in disposable FT-IR cards manufactured by 3M Corp. (Fisher Cat. 14385-861), were prepared by pre-wetting with 2 pi of methanol. A 1 pi aliquot of the aqueous protein solution was then added, and the membrane allowed to air dry at room temperature, before addition of 2 pi of matrix solution and final air drying. For those samples that were washed, after the protein solution had dried the membrane spot was vortexed in an aqueous 50% methanol solution for 30 seconds and air dried before addition of the matrix solution. 

Diisopropylethylamine (sequenal grade), trifluoroacetic add (sequenal grade), and 1,3-dicydohexylcarbodiimide (DCC) were obtained from Pierce. The carboxylic add modified polyethylene membranes were from the Pall Corporation (Long Island, NY). Zitex G-110 was from Norton Performance Plastics (Wayne, NJ). The amino acid thiohydantoins used in this study were synthesized as described (9). The Reliasil HPLC columns used in this study were obtained from Column Engineering (Ontario, CA). 

Fig 1. 1 pmol Parathyroid Hormone Fragment 39-68 (PHF), lOpmoI Pigeon Heart Cytochrome C (PHC), 10 pmol Bovin Serum Albumin (BSA) in saturated sinapinic acid matrix, desorbed from a. Polyethylene Membrane 113-2 b. Polypropylene Membrane 1222 c. Type 61 Disposable IR Card d. C8 Extraction Disk e. C18 Extraction Disk. 

In general, MALDI of samples fixed to membranes resulted in no loss of mass resolution or mass range. Spectra were extremely reproducible, and could usually be acquired at a lower threshold laser intensity. Figure 1 shows a peptide and protein mixture desorbed from each of the 5 tested membranes. All membranes except the CIS extraction disk produced well resolved spectra. Higher masses were better resolved in samples fixed to polyethylene membranes, while lower masses were better resolved by fixing samples to the Type 61 disposable IR card. Doubly and triply charged ions formed more readily upon desorption/ionization from all the membranes tested, than from stainless steel surfaces. 

Of the several membranes we examined, the polyethylene membranes were the most effective under all conditions. More specifically, the 113-2 membrane was most effective, followed by the IR membrane. The polypropylene membrane 1222 was the next most effective, followed by the C8 and C18 extraction disks. We suspect that the smaller pore sizes of polyethylene membranes results in retention of peptides and proteins at the membrane surface. Further work is need to establish this, however. 

Shelden and Thompson [42] used the following equation while modeling PV of toluene/ethanol mixmre with polyethylene membrane, and water/ethanol with both homogeneous and asymmetric PVA membranes. 

Thin films based on cellulose esters treated with an organic solvent were used for separation of isomeric xylenes, however, low values of factor jSp were achieved [130]. Modifications of hydrophyhc membranes were used for separation of Cg-aromatic isomers. Separation factor for p- to m-xylene was 1.69 [131]. Commercial polyvinyl alcohol membrane in the presence of CBf4 as a selective feed complexing agent was used to separate p- to m-xylene [133]. Dense homogenous polyethylene membranes were used for separation of aromatic Cg-isomers [132]. The rate of mass transport across the membrane increased... 

Jiang R, Benson HAE, Cross SE, and Roberts MS. In vitro human epidermal and polyethylene membrane penetration and retention of the sunscreen benzophenone-3 from a range of solvents. Pharm. Res. 1998 15(12) 1863-1868. 

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