Gas-separation membranes based on interpolymer complexes of sulfonate-containing aromatic polyamides

The gas-separation properties of membranes prepared from sulfonate-containing aromatic polyamide and aliphatic polyamines are studied. With the use of potentiometry, IR spectroscopy, and elemental analysis, it is shown that interpolymer complexes arising in these systems are primarily stabilized by electrostatic forces, while the degree of transformation in them is dependent on the basicity of polyamine and the conditions of the interpolymer reaction. The relationship between the nature of polyamine, the composition of the interpolymer complex, and the degree of transformation in it and the gas-separation characteristics of the membranes is established.     

Reaction between isoprene and aniline on complex palladium catalysts

Isoprene and aniline have been reacted on the catalytic system Pd(acac)₂-Ph₃P to form a mixture of isomeric telomers: N-(dimethyloctadien-2,7-yl-1)anilines and N-(dimethyloctadien-1,7-yl-3)anilines but on the catalytic system Pd(acac)₂-Ph₃P-CF₃COOH the main product is a mixture of N-(methylbuten-2-yl)aniline adducts. The reaction between N-methylaniline and isoprene on the latter catalyst also gives a mixture of N-methyl and N-(methylbuten-2-yl)aniline adducts.A. N. Nesmeyanov Institute of Organoelemental Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1794–1798, August, 1992.     

A new class of pressure-sensitive adhesives based on interpolymer and polymer-oligomer complexes

On the basis of previous concepts concerning the molecular nature of pressure-sensitive adhesion, a simple method of preparing new adhesives with the desired mechanical and adhesive behavior and water-absorbability via mixing of nonadhesive polymers has been developed. Pressure-sensitive adhesion is related to the combination of a high energy of cohesion and a large free volume, which leads to a high molecular mobility. This method is based on the formation of interpolymer or polymer-oligomer complexes during mixing of macromolecules capable of hydrogen, electrostatic, or ionic bonding. In interpolymer complexes, a high cohesion results from the formation of bonds between macromolecules carrying complementary groups in main chains, whereas free volume is related to defectiveness of the resulting network and formation of loops. In complexes formed by a high-molecular-mass polymer and an oligomer carrying complementary reactive groups at ends of short chains, a high energy of cohesion is related to their interaction with mainchain functional groups of the polymer, whereas a relatively large free volume is associated with the length and flexibility of intermacromolecular crosslinks via oligomer chains. The adhesive and viscoelastic properties of adhesives and their water absorbability are regulated by changes in the composition of mixtures of a film-forming polymer with a polymer or oligomer crosslinker and a plasticizer. In this case, an increase in cohesive strength is achieved owing to an increase in the crosslinker concentration, while the enhancement of free volume is ensured by the increasing plasticizer content in the blend. Adhesive materials capable of adherence to wet substrates, hydroactivated adhesives, and adhesion moisture sorbents have been prepared for the first time.     

Ternary complexes in analytical chemistry-I the niobium-pyrocatechol-sparteine complex

A ternary complex of niobium with pyrocatechol and sparteine has been investigated as a sensitive and selective system for the spectrophotometric determination of niobium. The complex is formed rapidly over a wide range of pH and is stable for several days. It is extracted quantitatively by some organic solvents. The interference from 40 cations and 10 anions has been examined, and synthetic mixtures and niobium ores have been analysed.     

Ternary complex formation dramatically enhances metal-sorbing vesicle selectivity

Conventional wisdom derived from experimental and theoretical studies of metal ion transport in liquid membrane systems suggests that the selective behavior of closely-related metal-sorbing vesicles (MSVs) should depend on independent interaction of ions with the membrane-bound carrier and with the encapsulated water soluble chelator. From a theoretical perspective, however, interdependent interactions between carrier, chelator and metal ion in a ternary complex can be designed into MSVs to augment significantly their metal ion selectivity. In this paper, we compare and contrast two transport models so as to elucidate MSV selectivity based on initial metal ion uptake rates from single and multi-component metal ion solutions. Our findings show that metal ion transport mechanisms that allow for interdependent interactions between the carrier and chelator, namely formation of a ternary metal ion–carrier–chelator complex at the inner vesicle wall, can enhance the overall selectivity of MSVs in accordance with a multiplicative, rather than additive, function of equilibrium metal–ligand binding constants. Therefore, design of MSVs that rely on metal ion transport mechanisms involving ternary complex formation may provide for a more economic route to extremely selective systems that employ less extensively tailored and less expensive metal-binding ligands.     

基于葡萄糖和苯硼酸基元之间的可逆共价键构筑多重响应性高分子复合物胶束

通过可逆加成-断裂链转移(RAFT)的聚合方法,合成了分别含有苯硼酸基元和葡萄糖基元的聚(N-异丙基丙烯酰胺)-b-聚(丙烯酰胺基苯硼酸)(PNIPAM-b-PAPBA)和聚(N-异丙基丙烯酰胺)-b-聚(丙烯酰葡萄糖胺)(PNIPAM-b-PAGA)二嵌段聚合物.由于苯硼酸和葡萄糖基元之间在弱碱性条件下(pH9.3)形成硼酸酯共价键,两种二嵌段聚合物的水溶液混合后能自发形成以PAPBA/PAGA络合物为核,PNIPAM为壳层的高分子复合物胶束.由于硼酸酯共价键在pH值和葡萄糖浓度改变时能可逆形成和断裂,以及胶束PNIPAM壳层的温敏性,所制备的基于苯硼酸/葡萄糖可逆共价键的高分子复合物胶束对pH、葡萄糖和温度具有多重响应性.     

The peculiarities of sorbtion mechanism of phenole molecules by films of PVA‐PAAN interpolymer complex

The peculiarities of sorbtion mechanism of phenole molecules by poly(vinylalcohol) and poly(acrylamide) (PVA‐PAA_N) films are examined. An analytical model of absorbtion process based on diffusive character of penetration of phenole molecules in polymer film with the following spontaneous capturing by selftuning traps is proposed. The analytical results can be easy compared with experimental data obtained by spectrophotometry method. The comparison of theory and experiment gives the average value of resulting diffusion lenght of phenole molecule during «free» life‐time <l>∼10⁻⁶ cm.     

Effect of chain compositions on interpolymer specific interaction in solutions

An interpolymer specific interaction of polymers with complementary proton donor units and proton acceptor units was studied with viscometry. In this study, poly(styrene-co-octyl acrylate-co-acrylic acid) as proton donating polymer (PDP) and poly(styrene-co-octyl acrylate-co-4-vinylpyridine) as proton accepting polymer (PAP) with different macromolecular chain compositions were prepared by emulsion copolymerization. Complexed solutions formed by PDP and PAP were studied with a novel interaction criterion k_a based on viscosity enhance factor. The effects of macromolecular chain compositions on the ability to interpolymer interaction and complex stoichiometry were discussed. The results showed that long chain alkyl acrylate units play an important role in the interpolymer specific interaction.     

The effect of the initial ratio of components in the formation of a ternary interpolymer complex on its composition and structure

The effect of the initial ratio of components in the formation of ternary interpolymer complexes with low-molecular-mass compounds of various chemical natures on the compositions and structures of polycomplexes has been studied. Complexes based on aniline, 4,4′-dipyridyl, lysine, poly(acrylic acid), and the sodium salt of polyphosphoric acid have been examined. It has been shown that an increase in the content of poly(acrylic acid) in the pristine reaction system results in a relative gain in its content in the reaction product.     

Effect of interpolymer complex formation on bioadhesive property and drug release phenomenon of compressed tablet consisting of chitosan and sodium hyaluronate

The bioadhesion property of tablets consisting of chitosan (CS) and sodium hyaluronate (HA) was investigated using a lyophilized porcine dermis as a model of mucous membrane. Release phenomena of brilliant blue FCF (BBL) from the CS-HA tablets were also studied. BBL was employed as a model compound of water-soluble drugs. Strong adhesion forces were observed when the tablets were prepared from HA alone or a physical mixture of CS and HA. The adhesion of CS tablets was also obtained but it was rather weak. No effect of pH values in the media was observed on the adhesion force in these tablets. On the other hand, the release rate of BBL from CS-HA tablets was greatly affected by the change of the polymer mixing ratio, suggesting a possible interaction between CS and HA in the tablet following water penetration into the tablet.     

Solution behavior of sulfonate ionomer interpolymer complexes

The interaction of metal sulfonate ionomers with polymers containing low levels of amines has been investigated in solution. For example, zinc sulfo EPDM and a styrene/vinyl pyridine copolymer form such complexes over broad concentration ranges. The resultant solutions offer enhanced viscosities at dilute polymer concentrations. At high polymer levels solutions based on these complexes are lower in viscosity than the ionomer alone. These interpolymer complexes have been shown to exhibit an improved property/rheology balance in bulk systems. In solution, polymer complexes provide control of hydrocarbon solution viscosity not available with conventional polymers. Reduced viscosity-concentration studies suggest that these polymer complexes are a result of the amine-containing polymer interacting with intramolecular-associated ionomer coils, which at higher concentrations form a pseudonetwork.     

A highly sensitive microRNA biosensor based on ruthenium oxide nanoparticle-initiated polymerization of aniline

Well-defined voltammetric current peaks of polyaniline were observed at biosensors hybridized with ruthenium oxide nanoparticle-tagged microRNAs and incubated in a mixture of aniline/H(2)O(2), which can be used for direct microRNA expression profiling with excellent sensitivity.     

Study of interpolymer complex formation of polyvinylpyrrolidone and poly(ethylene oxide) with phenolic polymers in nonaqueous media

A study was made of interpolymer complex formation between polyvinylpyrrolidone (PVP) and poly(ethylene oxide) (PEO) with phenolic polymers (PPF) in an acetone–methanol mixture by several methods; for example, viscosity, potentiometry, conductometry, turbidity, and precipitate (complex) weight. A distinct stepwise complex formation between PVP and phenolic polymers was observed by these methods. As in polycarboxylic acid, however, PEO formed a 1:1 complex with phenolic polymers. Some of these observations have been interpreted in terms of the structure of the polymers, preferential solvation of the component polymers, and the probable change in conformation of the complex molecules in mixed solvents.     

Influence of preferential solvation on the interpolymer complex formation between methacrylic acid–methacrylamide copolymer and poly(vinyl pyrrolidone)

Interpolymer complex formation has been studied between methacrylic acid–methacrylamide copolymer and poly(vinyl pyrrolidone) in acetone–water mixtures of different compositions. At a specific composition of the solvent (e.g., 70% water + 30% acetone by volume), the intrinsic viscosity of the copolymer and the reduced viscosity of 1:1 interpolymer complex had minimum values. Preferential solvation coefficients (λ/C) have been calculated for the various compositions of the solvent mixtures. An excellent coincidence could be obtained between the maximum (λ/C) and the minimum in the viscosity of the polymer solutions. Interpretations have been sought in terms of conformational change of the copolymer at the specific composition of the solvent mixture.     

Ternary Flexible Electro‐resistive Memory Device based on Small Molecules

Flexible memory devices have continued to attract more attention due to the increasing requirement for miniaturization, flexibility, and portability for further electronic applications. However, all reported flexible memory devices have binary memory characteristics, which cannot meet the demand of ever‐growing information explosion. Organic resistive switching random access memory (RRAM) has plenty of advantages such as simple structure, facile processing, low power consumption, high packaging density, as well as the ability to store multiple states per bit (multilevel). In this study, we report a small molecule‐based flexible ternary memory device for the first time. The flexible device maintains its ternary memory behavior under different bending conditions and within 500 bending cycles. The length of the alkyl chains in the molecular backbone play a significant role in molecular stacking, thus guaranteeing satisfactory memory and mechanical properties.     

Effect of added salt on the stability of hydrogen-bonded interpolymer complexes

Association of macromolecules in aqueous media through hydrogen bonding results in the formation of discrete interpolymer complexes (IPCs). In this work, the effect of added salt on the stability of IPCs consisting of polyacrylic acid and either a flexible polymer (polyethylene oxide or polyvinylpyrrolidone) or a semirigid polymer (hydroxy propylcellulose) is examined by a combination of spectrophotometry, viscometry and potentiometry. Addition of a neutral salt (e.g., NaCl) typically results in IPC aggregation. The response of the IPCs to salts that promote salting-in (i.e., LiSCN, NaSCN and GuSCN, where Gu denotes guanidine) is strongly cation-dependent, since Li⁺ cations induce an increase in solution pH, whereas Gu⁺ cations compete with polyacrylic acid for complexation sites. The degree of complexation (), calculated from potentiometric data, is greatest for IPCs in the absence of salt and is found to decrease in the order NaCl>NaSCN>GuSCN. Addition of salts that induce salting-in at polymer solution concentrations favoring complexation is found to enhance IPC solubility (and reduce ) until the IPC particles are either completely solubilized or dissociated.     

Iodide ion selective poly(aniline) solid contact electrode based on quinine-cu ionophores

Iodide ion selective poly(aniline) solid contact electrode based on quinine-Cu ionophore as a sensing material has been successfully developed. The electrode exhibits good linear response of 52.0 mV/decade (at 20 ± 0.2°C, r ² = 0.9998) within the concentration range of 1 × 10^−6.4–1 × 10^−1.0 M KI. The composition of this electrode was quinine-Cu 2.0: PVC 30.0: bis(2-ethylhexyl)sebacate 68.0 (mass). This plasticizer provides the best response characteristics. The electrode shows good selectivity for iodide ion in comparison with any other anions and is suitable for use with aqueous solutions of pH 3.3–9.4. The standard deviations of the measured EMF difference were ±1.4 and ±1.3 mV for iodide sample solutions of 1.0 × 10⁻² M and 1.0 × 10⁻³ M, respectively. The stabilization time was less than 10 min and response time was less than 15 sec.     

Ternary ion-association complex based ion imprinted polymers (IIPs) for trace determination of palladium(II) in environmental samples

A new ion imprinted polymer (IIP) material was synthesized by co-polymerization of palladium-iodide-vinyl pyridinium/palladium-thiocyanate-vinyl pyridinium ion ternary ion-association complex taken in methanol/DMSO with 2-hydroxyethyl methacrylate (functional monomer) and ethylene glycol dimethacrylate (crosslinking monomer) in the presence of 2,2′-azobisisobutryonitrile (initiator). The imprinted anionic species [PdI₄]²⁻ or [Pd(SCN)₄]²⁻ were removed by leaching the dried and powdered materials particles for 18 h with 6 M HCl to obtain leached IIP particles. Non-imprinted/control polymers were also prepared in a similar fashion without the template. Various parameters that influence the percent extraction of palladium, viz. concentration of KI or KSCN, pH, weight of polymer particles, preconcentration and elution times, aqueous phase volume, etc., were systematically studied for both the systems, i.e., in batch as well as flow injection modes. As the on-line flow injection-flame atomic absorption spectrometric (FI-FAAS) allow offer higher enrichment factor, better precision and can analyze more samples for a given time, compared to batch method, this procedure is preferred for the analysis of palladium present in the street/fan blade dust samples collected from busy cities of India and the values obtained were compared with the standard ICPMS values.