Biphase Media Research Articles

Effects of pre-bloom spraying thidiazuron and different embryo development media on seedless grape embryo rescue

ABSTRACT Embryo rescue technology has been widely applied in seedless grape breeding, but its success depends on many factors. Here, two Vitis vinifera seedless varieties ‘Qinhong No.2’ and ‘Qinhong No.10’ were used as research objects, the inflorescences were sprayed with 0.5 mg·L−1 thidiazuron 10 days before flowering, and then the ovules from open- and self-pollination of them were cultured in solid–liquid biphase MM3 media to investigate the effect of thidiazuron on embryo rescue. Under natural condition, the ovules of open- and self-pollination were inoculated onto three solid–liquid biphase media NN, ER, and MM3 to compare the efficiency of embryo rescue. The results showed that pre-bloom spraying thidiazuron significantly promoted ovule development and further improved the effect of embryo rescue in vitro. After applying thidiazuron, the embryo development rate, germination rate, and seedling rate of the four combinations reached 30.77%–42.62%, 29.36%–41.64%, and 22.02%–40.33%, respectively. Open-pollination of the two varieties provided better effects for culturing than their self-pollination, and the MM3 medium was always more suitable for embryo development than either the ER or NN medium. Furthermore, the germination rate of bare embryos of ‘Qinhong No. 10’ open-pollination on solid WPM medium surpassed that of ovules (without embryo stripping) on solid NN medium. HIGHLIGHTS Pre-bloom spraying TDZ could improve the effect of embryo rescue of seedless grape. The embryo rescue effect was better in open- than self-pollinated seedless grapes. Solid–liquid biphase MM3 was more suitable for embryo rescue than an ER or NN medium. The seedling rate of bare embryos on WPM medium exceeded that of ovules on NN medium. Overall, 2312 hybrids from the four combinations were obtained via embryo rescue.

Fluorination Effect on the Gibbs Transfer Energy for Methylene Group from 1,2-Dichloroethane or 1,1,1,2,3,4,4,5,5,5-​Decafluoropentane to Water.

The ion-transfer reactions of alkyl and perfluoroalkyl carboxylate ions (CH3(CH2)n-2COO- and CF3(CF2)n-2COO-) at 1,2-dichloroethane (DCE) | water (W) and 1,1,1,2,3,4,4,5,5,5-decafluoropentane (DFP) | W interfaces were investigated. These ions gave reversible or quasi-reversible voltammetric waves due to their ion transfer across the interfaces, and the formal potentials and the formal Gibbs transfer energies from a non-aqueous solvent to water, ΔG°'tr,α→W (α = DCE and DFP), were determined. The ΔG°'tr,α→W for CH3(CH2)n-2COO- and CF3(CF2)n-2COO- linearly increased with n, allowing for estimating ΔG°'tr,α→W for methylene groups. The estimated value of ΔG°'tr,DCE→W for the -CH2- group was higher than that of ΔG°'tr,DCE→W for the -CH2- group, whereas the ΔG°'tr,DCE→W for the -CF2- group was lower than that of ΔG°'tr,DCE→W for the -CF2- group, indicating that the -CH2- (or -CF2-) group is more favorably (or unfavorably) solvated in the DCE phase compared to the DFP phase. From the estimated values, the fluorination effect of alkyl chains on partitioning the alkyl group between the biphase media has also been discussed.

The method of cleaning and modification of the material for bone xenografts in bi-phase media containing high pressure CO2

In the present work, a promising method was proposed for purification of fragments of animal bone tissue from high-molecular weight compounds in bi-phase media containing high-pressure CO2 for the first time, namely, in solutions of carbonic and peroxycarbonic acids. The effectiveness of this purification was confirmed by SEM and IR spectroscopy. It turned out that during the exposure of bone fragments in solutions of carbonic and peroxycarbonic acids under high pressure of CO2, the components of the mineral phase of bone tissue are also extracted, which allows to obtain highly dispersed particles of hydroxyapatite during the deposition of the extract. The structure and composition of the extracts were investigated by XRD analysis and SEM.

A Method for Purification and Modification of a Bone Xenotransplant Material in Biphase Media Containing High-Pressure CO2

A promising method was proposed for the first time for purification of animal bone tissue fragments from high-molecular weight compounds in biphase media containing high-pressure CO2 (solutions of carbonic and peroxycarbonic acids). The efficiency of this purification was confirmed by SEM and IR spectroscopy. It turned out that, during the exposure of bone fragments in solutions of carbonic and peroxycarbonic acids at high CO2 pressure, mineral phase components of bone tissue are also extracted, which can be used to obtain highly dispersed hydroxyapatite particles upon extract reprecipitation. The structure and composition of the extracts were investigated by X-ray diffraction and scanning electron microscopy (SEM).

Phase transfer catalyst aided radical polymerization of n-butyl acrylate in two-phase system: a kinetic study

The kinetics of radical polymerization of butyl acrylate initiated by potassium peroxydisulphate and cetyltrimethylammonium bromide as phase transfer catalyst (PTC) was carried out under inert and unstirred conditions at constant temperature of 60 ± 2 °C in ethyl acetate–water biphase media. The polymerization reactions were relatively fast in the two-phase systems with phase transfer agent whereas extremely sluggish in the system without PTC. Use of PTC accelerates the reaction effectively if the reactants located in two phase. The effects of rate of polymerization (R p) on various experimental conditions such as different concentrations of monomer, initiator, phase transfer catalyst, temperature, and different ionic strength of the medium were explored. The order with respect to monomer, initiator and phase transfer catalyst was found to be unity. The R p is independent of ionic strength and pH of the medium. However, an increase in the polarity of solvent has slightly increased the R p value. Based on the results obtained, a plausible mechanism has been proposed for the polymerization reaction. The obtained polymer was confirmed by FT-IR analysis.

Multi-site phase transfer catalyst assisted radical polymerisation of glycidyl methacrylate using potassium peroxydisulphate as initiator – a kinetic study

In this work, the kinetics and mechanism of free-radical polymerisation of glycidyl methacrylate (GMA) using potassium peroxydisulphate (PDS) as water soluble initiator in the presence of synthesized 1, 4-Bis (tributyl methyl ammonium) benzene dichloride (TBMABDC) as multi-site phase transfer catalyst (MPTC) was studied. The polymerisation reactions were carried out under inert and unstirred conditions at constant temperature of 60 ± 1°C in cyclohexane/water biphase media. The role of concentrations of monomer, initiator, catalyst and volume fraction of aqueous phase, solvent polarity and temperature on the rate of polymerisation (Rp) was ascertained. The order with respect to monomer and initiator was found to be unity. The order with respect to catalyst was found to be 0.51. The rate of polymerisation is independent of ionic strength and pH of the medium. However, an increase in the polarity of solvent has slightly increased the Rp value. Based on the results obtained, a suitable kinetic scheme has been proposed to account for the experimental observations and its significance discussed.

Synthesis of SAPO-11 and MgAPO-11 Molecular Sieves in Water–Butanol Biphase Media

SAPO-11 and MgAPO-11 molecular sieves were synthesized in water-butanol biphase media. The water-butanol biphase media favored the incorporation of Si into SAPO-11 and the formation of more acid sites. Therefore, the Pt catalyst supported on the SAPO-11 synthesized in the biphase medium exhibited much higher catalytic activity for the hydroisomerization of n-dodecane than that supported on the SAPO-11 synthesized in an aqueous medium. In contrast, the water-butanol biphase media were unfavorable for the Mg substitution into the framework, and thus the acid sites and the catalytic activity of Pt/MgAPO-11 decreased.

Polymerization of Butyl Acrylate using Potassium Peroxy Disulfate as Initiator in the Presence of Phase Transfer Catalyst—A Kinetic Study

The kinetics and mechanism of free radical polymerization of butyl acrylate (BA), using potassium peroxydisulfate (K2S2O8) as initiator in the presence of propiophenonebenzyldimethylammonium chloride (PPBDMAC) as phase transfer catalyst (PTC) has been studied. The reactions were carried out under inert, unstirred conditions and at a constant temperature of 60°C in cyclohexanone/water biphase media. The dependence of the rate of polymerization (Rp) on various experimental conditions such as different concentrations of monomer, initiator, phase transfer catalyst, varying acid and ionic strength, temperature, and volume fraction of aqueous phase were studied. The order with respect to monomer, initiator, and the phase transfer catalyst were found to be 1.5, 0.5, and 0.5, respectively. The rate of polymerization was independent of acid and ionic strength. Based on the results, a mechanism has been proposed for the polymerization reaction.

FREE RADICAL POLYMERIZATION OF METHYL METHACRYLATE IN THE PRESENCE OF PHASE TRANSFER CATALYST—A KINETIC STUDY

The kinetics of free radial polymerization of methyl methacrylate (MMA) using potassium peroxydisulfate as initiator in the presence of propiophenonebenzyldimethylammonium chloride as phase transfer catalyst were studied. The reactions were carried out under inert and unstirred conditions at constant temperature of 60°C in cyclohexanone/water biphase media. The dependence of the rate of polymerization on various experimental conditions, such as different concentrations of monomer, initiator and phase transfer catalyst (PTC) and different ionic strength, temperature and volume fraction of aqueous phase was studied. The order with respect to monomer, initiator and phase transfer catalyst was found to be 1, 0.5 and 0.5 respectively. The rate of polymerization (Rp) is independent of ionic strength and pH. However, an increase in the polarity of solvent and volume fraction of aqueous phase has slightly increased the Rp value. Based on the results obtained, a mechanism has been proposed for the polymerization reaction.

Synthesis of Rhodium Complexes with Novel Perfluoroalkyl Substituted Cyclopentadienyl Ligands

Mixtures of isomers of (perfluoroalkyl)tetramethylcyclopenta-1,3-dienes (CH3)4C5H(CF2)nCF3 (n = 3, 5, 7, 9) were synthesized as precursors of new cyclopentadienyl ligands for organotransition metal catalysis in fluorous biphase media and characterized by combination of GC-MS and 13C NMR spectroscopy. Rhodium(III) chloro complexes [Rh{(CH3)4C5(CF2)nCF3}Cl2]2 and rhodium(I) carbonyl complexes [Rh{(CH3)4C5(CF2)nCF3}(CO)2] were prepared from the cyclopentadienes and molecular structure of [Rh{(CH3)4C5(CF2)5CF3}Cl2]2 was determined by X-ray diffraction. The ligands are electronically close to the unsubstituted cyclopentadienyl as shown by values of carbonyl stretching frequencies in the carbonyl complexes. Neither carbonyl frequencies nor NMR chemical shifts of the complexes are substantially affected by the length of the perfluoroalkyl chain.

Phase-Transfer Catalysis: Free-Radical Polymerization of Methyl Methacrylate using K2S2O8-Quaternary Ammonium Salt Catalyst System. A Kinetic Study

Abstract The kinetics of phase-transfer-agent-assisted free-radical polymerization of methyl methacrylate using K2S2O8 as the water-soluble initiator and triethylbenzylammonium chloride (TEBA) as the phase-transfer catalyst (PTC) was investigated in toluene-water biphase media at 60°C. The effect of varying [MMA], [K2S2O8], [TEBA], [H+], the ionic strength of the medium, and the temperature on the rate of polymerization (R p) was studied. R p was found to be proportional to [MMA]2, [K2S2O8]1, and [TEBA]0.5. Based on the kinetic results, a mechanism involving initiation of polymerization by phase-transferred S2O8 2- and termination by Q+ (quaternary ammonium ion) is proposed.

Radical Copolymerization of Unsaturated Nitriles in Biphase Media: A Review

Abstract The review concentrates on the major aspects of radical copolymerization of acrylonitrile and methacrylonitrile with various comonomers in biphase media, namely, in thermodynamically bad solvents and precipitators. Some specific features of homopolymerization of nitriles in heterophase media are discussed too, and this makes the treatment of the data on copolymerization more grounded. The effects depending on the topology of the process of copolymerization are picked out and the theories explaining them are presented. Special attention is centered on the peculiarities of the synthesis of hydrophylic copolymers containing nitrile units. The problem of applicability of the scheme of Mayo and Lewis for the systems under study is discussed, emphasizing that the treatment of experimental data in the form of composition diagrams is not “self-controlled.” It is shown that a more sensitive criterion for an estimation of heterophase copolymerization is chemical heterogeneity of copolymers synthesized, namely, integral curves of distribution by composition of copolymers. Phase-transfer-catalyzed copolymerization of unsaturated nitriles as a new kind of heterophase copolymerization is presented.