A novel immunoassay system and bioseparation process based on thermal phase separating polymers

Poly-N-isopropylacrylamide (polyNIPAAm), a water-soluble, thermally precipitating synthetic polymer, has been conjugated together with a monoclonal antibody (MAb) and utilized in a novel separation method for an immunoassay. The PolyMPAAm precipitates out of water above a critical temperature of 31°C, enabling a polymerbound immune complex to be separated from the solution. The principal advantages of this method are that it utilizes a homogeneous incubation for the antigen-antibody reaction, plus, it has the ability to assay large-molecular-weight antigens with sensitivities equivalent to other nonisotopic heterogeneous immunoassays. In addition, since the polymer-immune complex may be reversibly redissolved by cooling, the method may be used both to concentrate the signal and isolate the analyte. This general technique may also be used for a wide variety of separation processes in addition to immunoassays, in which a specific component in a biological fluid, industrial process stream, or body of water is to be isolated for analysis, recovery, or disposal. Thus, product recovery and/or toxin or pollutant removal processes are possible with this methodology.     

Nanoporous materials: a good opportunity for nanosciences

This paper emphasizes the wide possibilities open to organometallic chemistry by the bottom-up approach for nanosciences. In this new field of research, organometallic chemistry and coordination chemistry are in position to play a very important role in the development of nanomaterials. At first, organometallic and coordination chemistries will be the mothers of plenty of nanotools, which are the elemental bricks of nanosciences. The nanomaterials are obtained from them either by inclusion in a matrix (Nanocomposites) or by grafting methods (grafted nanomaterials). However, the most exciting field of investigation are the nanostructured hybrid materials which permit to open new fields of investigation such as self-organization of organic moieties or the coordination chemistry in the solid. Some examples are given. Moreover, the organometallic chemistry performed on both the framework and the pores of the nanoporous solids obtained by sol-gel chemistry in the presence of structure directing agents is opening the way to smart materials. These materials will have the ability to couple interactively two different properties.     

Heat resistance of composite sorption-active materials based on zeolite and fluoroethylene polymers

Relationship was found between the temperature of thermal degradation of composite sorption-active materials based on fluorinated ethylene polymers and the content of NaX zeolite in these materials.     

Utilization of sulfur-containing products of pyrolysis of a raw mixture based on peat and polymers

Pyrolysis gases and condensates were analyzed for inorganic compounds and total sulfur in relation to the pyrolysis temperature, with the aim to improve a process for preparing granulated activated carbons from peat, polymer wastes, and sulfuric acid.     

Synthesis and characterization of benzobisthiazole based polymers as donor materials for organic solar cells

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Evaluation of the potential of nonlinear gradients for separating a ternary mixture

The potential of applying nonlinear gradients in preparative chromatography is evaluated theoretically and experimentally. The second eluting component of a ternary model mixture is considered as the target component. Systematic gradient resolution experiments were conducted for this mixture using reversed phase chromatography. In preliminary experimental investigations the effect of the mobile phase composition on the specific distribution equilibria was quantified. Concave and convex solvent strength gradients were analysed and compared with conventional linear gradients. Main result of the study is the fact that significant improvement in productivity can be achieved if the gradient shapes are designed carefully.     

Choice of an extractive separating agent for the 1-pentanol-cyclohexanone binary mixture

Phase equilibria in binary and ternary systems formed by the components to be separated (1-pentanol, cyclohexanone) with extractive separating agents (methyl Cellosolve, butyl Cellosolve, aniline, acetophenone, ethylene glycol) were studied.     

Design of a production gas chromatograph for separating heat-sensitive materials

Summary A rational design procedure for production and preparative chromatography has previously been devised. Here the procedure is applied to designing a pilot scale production gas chromatograph for separating two heatsensitive essential oil mixtures: geraniol/nerol and -/-pinenes. Analytical scale experiments provide some of the data required. A critical feature of the design is that these materials degrade at temperatures well below their boiling points. The design study leads, first, to selection of carrier gas, stationary phase and solid support materials, and then to quantitative determination of column temperature, evaporator temperature, feed concentration in the carrier gas, column diameter, particle size of support, carrier velocity, ratio of recycled to inject feed, injection time, column length, and liquid phase loading.Presented at the 14th International Symposium on Chromatography London, September, 1982.     

Preparation of bio-based polymers for materials applications

A new technology developed by us for the synthesis of well defined, tailored cellulose-synthetic polymer graft polymers and crosslinked cellulose graft polymers with control over the molecular weight of the synthetic polymer graft, a high degree of graft substitution, and knowledge of the backbone-graft linkage is reviewed. The potential of bio-based polymers using these new tailored cellulosic graft polymers for use in plastics, resins, and composite applications is discussed. The new graft polymers can function as compatibilizers/interfacial agents in the preparation of biopolymer-synthetic polymer composites and blends with the desirable properties of the constitutent polymers incorporated into the new material system.     

Multifunctional polymers as multi-role materials for photonics

Multifunctional polymers can play multi-roles such as laser light source, passive interconnects, optical signal processing and optical data storage in the development of photonics technology. In this paper, two approaches to achieve nanostructure control to introduce multifunctionality at both molecular and bulk levels are presented. A novel concept of multiphasic nanostructured composites is discussed. Various applications of a specific multifunctional property introduced by strong two-photon absorption and efficient fluorescence are presented. The combined action of these two functions produces upconverted emission. Specific applications discussed are upconversion lasing, optical data storage, confocal microscopy, and photodynamic therapy.     

Preparation of magnetic molecularly imprinted polymers for separating rutin from Chinese medicinal plants

The preparation of magnetic molecularly imprinted polymers (MMIPs) which can be used for the separation and purification of rutin from Chinese medicinal plants has been proposed. By applying the improved co-precipitation method, magnetic Fe(3)O(4) particles were easily prepared, followed by the modification of TEOS and functionalization with -CH=CH(2). Using functionalized Fe(3)O(4) particles as the magnetic cores, rutin as the template, and acrylamide as the functional monomer, MMIPs were synthesized by surface-imprinted polymerization under the protection of nitrogen gas and successive mechanical stirring at 60 °C for 24 h. Magnetic non-molecularly imprinted polymers (MNIPs) were also prepared with the same synthesis procedure as with MMIPs only without the presence of rutin. Magnetic particles were characterized by FT-IR, XRD, and TG analysis. And the selectivity of MMIPs was also investigated in detail. In addition, the performance of the MMIPs for the adsorption of rutin in the analysis of Chinese medicinal plants was assessed. The mean recoveries were 84.33% (RSD: 3.22%, n = 3) for Saururus chinensis (Lour.) Bail and 85.20% (RSD: 3.58%, n = 3) for Flos Sophorae, respectively, which showed that the prepared MMIPs with many advantages possess the value of practical application.     

Pervaporation for separating benzene/cyclohexane mixture by P(AA-MA) copolymer membranes

P(AA-MA)copolymers composed of acrylic acid and methyl acrylate with different molecular weights and sequence structures were synthesized by combination of ATRP and selective hydrolysis.These copolymers were used as membrane materials to separate benzene/cyclohexane mixture by pervaporation.The effects of molecular weight and sequence structure of the copolymers on the pervaporation performance were investigated in detail.For the random copolymers,the permeate flux decreased rapidly with the increasing of molecular weight.The separation factor was also influenced by the molecular weight,which was changed from no selectivity to cyclohexane selectivity with increasing the molecular weight.Contrarily,the block copolymer membrane showed good benzene selectivity with separation factor of 4.3 and permeate flux of 157 g/(m~2h)to 50 wt%benzene/cyclohexane mixture.     

Quasi-one-dimensional materials: polymers and chains

Results of density-functional calculations on materials that can be considered being quasi-1D are reported. The materials include some based on carbon (fullerene nanotubes and a polyyne), chains of metal atoms (Pb, Au, and Ag), and charged chains as building blocks of crystals (PtS₂ chains surrounded by K atoms and NiN chains separated by Ca atoms). In many cases it is found that 2D or 3D behaviors can be recognized, but in some cases the smaller changes due to the change from true 3D or 2D to quasi-1D have profound effects.     

Carbazole main-chain polymers for multifunctional materials: Synthesis and characterization

A series of α,ω-bis(3-formylcarbazolyl)alkane monomers have been prepared starting from carbazole and α,ω-dibromoalkane in two steps. Main-chain polymers with carbazole substituted with one acceptor group as the nonlinear optical (NLO) chromophores and photoconductive moieties were synthesized by the Knoevenagel polycondensation of α,ω-bis(3-formylcarbazolyl)alkane and 1,6-bis(cyanoacetoxy)hexane using 4-(N,N-dimethyl)pyridine (DMAP) as a base. This Knoevenagel polycondensation involved two stages: polycondensation was first carried out in tetrahydrofuran solution, and then polycondensation was allowed to continue in the solid-state after removal of solvent. All of these main-chain polymers characterized by spectroscopic methods and elemental analyses are soluble in common low boiling organic solvents, such as chloroform. These polymers were found to be amorphous with glass transition temperatures in the range of 94–117°C by differential scanning calorimetry. This two-stage polycondensation gave polymers with weight-average molecular weight in the range of 25,000–72,000 g/mol by gel permeation chromatography. The study of the nonlinear optical and photorefractive properties of these polymers is in progress. © 1996 John Wiley & Sons, Inc.     

Electrical conductivity and photoconductivity of film materials based on heteropolynuclear Cu/Cd complexes and organic polymers

We have studied the characteristic features of the electrical conductivity and photoconductivity of films of composites based on polyvinyl butyral and acrylonitrile butadiene styrene with added heteropolynuclear Cu/Cd complexes having one-dimensional and two-dimensional polymer structures and with added anthracene, epoxypropyl carbazole, and C₆₀ organofullerene molecules. Normal positive and abnormal negative effects of photoconductivity were found. Kinetic model of the photoconductivity was proposed. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 2, pp. 107–112, March–April, 2006.     

An improved prototype apparatus and process for separating cellulosic materials from municipal solid waste

Applied Biochemistry and Biotechnology - A new prototype steam classification process apparatus has been designed, fabricated, and tested. The optimum operating conditions for the unit have been...     

Biodeterioration of polymers and polymer composite materials

The problem of the biodeterioration of polymers and polymer composite materials is considered. Products made from both thermoplastic and thermosetting polymers are found to undergo biodeterioration. An analysis of methods for investigating biocorrosion is performed. It is established that the application of conventional testing methods under laboratory conditions is restricted due to their complexity and work content, as well as because of the low efficiency at the stage of material development. In connection with this, the possibility of applying indirect investigation methods for the qualitative and quantitative evaluation of biodeteriorations of polymers is considered, and testing is carried out on samples of crosslinked polymers in aerotanks. It is shown that biocorrosion is not caused by the microorganisms themselves, but rather by their waste products, e.g., organic acids and ferments. The possibility of evaluating biocorrosion via modeling biodeterioration using solutions of individual substances (various organic acids) is revealed. Urgent problems of investigations on this topic are defined.     

ESR imaging of polymers and solid materials

EPR imaging was applied to the study of several important processes in polymers and materials. The solvent diffusion and induced swelling was visualized in the water/DMF or toluene/DMF interactions with polycarbonate or polystyrene molded rods. The cross-sectional images revealed non-homogeneous solute/solvent diffusion, rod expansion and crack development. The ESR lineshapes in all cases above confirmed that the nitroxide imaging agent did not interact significantly with the polymer matrix; thus the paramagnetic distribution reflected bulk solvent distribution quite well. The diffusion of an electrolyte buffer (Krebs) solution containing a nitroxide spin probe was followed in a cross-sectional image of a polyacrylamide gel rod. A one-dimensional radial diffusion constant was calculated for the solvent piperidinol nitroxide spin probe, TEMPOL. Lastly, solid coal rods were monitored during mild pyrolysis at 150°C in air. Here the naturally occurring organic radical composition was imaged. Even with the increase in total ESR signal and subsequent decline to ca. the initial levels, the coal rod cross-section was essentially homogeneous in paramagnetic centers throughout the heating process. All of the imaging above utilized a homemade L-band, flat loop surface coil spectrometer.     

Lessons learned from research on photorefractive polymers and molecular materials

Organic photorefractive (PR) materials are a new kind of electrooptic substance that emerged 10 years ago. These are very complicated materials that possess both electrooptic effects and photoconductivity. It is challenging to integrate these properties into a single polymer system that will exhibit this PR effect. This article highlights our efforts in the past nine years in synthesizing and characterizing fully functionalized organic PR materials. I emphasize the lessons we have learned from this research, which may be more valuable to those who are interested in this area. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2557–2564, 2001