Ordinary Solvents Research Articles

Rheology, stability, and physicochemical properties of NaOH-tannic acid solvent for β-chitin dissolution

The applicability of chitin in food systems is limited by its poor solubility in ordinary solvents. This study explores a novel solvent system composed of sodium hydroxide and tannic acid (NaOH/TA) in combination with a repeated freeze-thaw process for dissolving chitin. The highest chitin solubility in 8% NaOH/0.3% TA and 10% NaOH/0.3% TA was 2.1% and 2.3% (w/v), respectively. The lower NaOH and excessive tannic acid content may lead to reduction of chitin solubility. We also observed a unique rheological property of the chitin/NaOH/TA system. A higher concentration of TA reduced the chitin solution's shear viscosity, storage modulus, loss modulus, and gelling temperature. Its shear viscosity decreases with increasing shear rate, showing a shear thinning behavior. When the chitin/NaOH/TA solution system was stored at 30oC, the crystalline degree of chitin decreased, and the diffraction peak shifted, suggesting the formation of different intermolecular forces. The TA contents show no significant effect on the crystallinity of chitin. With increased storage time, the molecular weight of chitin decreased, and the degree of deacetylation (DD) increased. These results underscore the potential applications of the chitin/NaOH/TA system in the food industry.

Verification of the Inverse Scale Effect Hypothesis on Viscosity and Diffusion by Azo-Amino Acid Schiff Base Copper Complexes

Microdroplets generated in microfluidic devices are attracting attention as a new chemical reaction field and are expected to improve reactivity. One of the effects of microscaling is that the ratio of the force that acts on the diffusion and movement of substances to gravity is different from that of ordinary solvents. Recently, we proposed a hypothesis for determining reaction acceleration through micro-miniaturization: If a reaction is inhibited by setting the volume and viscosity of the solution to conditions that are unfavorable to the reaction on a normal scale, that reaction can be promoted in microfluidics. Therefore, for the purpose of this verification, (1) we used an amino acid Schiff base copper(II) complex with an azobenzene group to demonstrate the polarization-induced orientation in a polymer film (the redirection that is mechanically maintained in a soft matter matrix). Numerical data on optical anisotropy parameters were reported. (2) When the reaction is confirmed to be promoted in laminar flow in a microfluidic device and its azo derivative, a copper(II) complex is used to increase the solvent viscosity or diffusion during synthesis on a normally large scale. We will obtain and discuss data on the investigation of changing the solvent volume as a region. The range of experimental conditions for volume and viscosity did not lead to an improvement in synthetic yield, nor did (3) the comparison of solvents and viscosity for single-crystal growth of amino acid Schiff base copper(II) complexes having azobenzene groups. A solvent whose viscosity was measured was used, but microcrystals were obtained using the diffusion method.

Exploring the Solubility Limits of Edaravone in Neat Solvents and Binary Mixtures: Experimental and Machine Learning Study.

This study explores the edaravone solubility space encompassing both neat and binary dissolution media. Efforts were made to reveal the inherent concentration limits of common pure and mixed solvents. For this purpose, the published solubility data of the title drug were scrupulously inspected and cured, which made the dataset consistent and coherent. However, the lack of some important types of solvents in the collection called for an extension of the available pool of edaravone solubility data. Hence, new measurements were performed to collect edaravone solubility values in polar non-protic and diprotic media. Such an extended set of data was used in the machine learning process for tuning the parameters of regressor models and formulating the ensemble for predicting new data. In both phases, namely the model training and ensemble formulation, close attention was paid not only to minimizing the deviation of computed values from the experimental ones but also to ensuring high predictive power and accurate solubility computations for new systems. Furthermore, the environmental friendliness characteristics determined based on the common green solvent selection criteria, were included in the analysis. Our applied protocol led to the conclusion that the solubility space defined by ordinary solvents is limited, and it is unlikely to find solvents that are better suited for edaravone dissolution than those described in this manuscript. The theoretical framework presented in this study provides a precise guideline for conducting experiments, as well as saving time and resources in the pursuit of new findings.

Construction of effective transmission channels by anchoring metal‐organic framework on side‐chain sulfonated poly(arylene ether ketone sulfone) for fuel cells

A series of novel organic-inorganic hybrid membranes assembled by side-chain type sulfonated poly(arylene ether ketone sulfone) with amino groups (Am-SPAEKS-DBS) and ZIF-67 were prepared. Am-SPAEKS-DBS containing double bonds was synthesized by condensation polymerization, and the AMPS was grafted onto the main chain by post sulfonation. ZIF-67 was prepared by an ordinary solvent method. The structures of ZIF-67, Am-SPAEKS-DBS, and hybrid membranes were analyzed by proton nuclear magnetic resonance (1H NMR), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD) and Fourier transform infrared (FT-IR). All hybrid membranes had good dimensional stability and excellent oxidation stability. In addition, the swelling ratios of all hybrid membranes were low (<17.46%) at even 100°C, and the oxidative stability was higher than 92%. The proton conductivities of this series of membranes were much higher (0.0540.069 S cm−1 at 30°C, 0.088-0.116 S cm−1 at 80°C) than pure membrane (0.038 S cm−1 at 30°C, 0.076 S cm−1 at 80°C). The experimental results exhibited that the comprehensive properties of hybrid membranes are good, and hybrid membranes had substantially possible as proton exchange membranes. Highlights Metal-organic frameworks were anchored on side-chain type organic polymer backbone. The hybrid PEMs showed good dimensional stability and excellent oxidation stability. The imidazole as a ligand in ZIF-67 contributes a part of the dissociated protons.

Photochemical stability of g-C3N4 in the gas phase

For the successful environmental applications of g-C3N4 photocatalyst, sufficient photochemical stability is an important parameter. The present work is thus devoted to the investigation of the photostability of g-C3N4 materials in terms of production of organic compounds under UV and VIS light irradiation; for the purpose of comparison, TiO2 material was also investigated. The measurement of total organic compounds in air shows the production of organic compounds when g-C3N4 materials are irradiated with UV or VIS light. Detailed analysis of organic compounds present in the air was performed using GC-MS. When both materials (TiO2 and g-C3N4) were exposed in the dark, the air contained traces of ordinary solvents (acetone, hexane, ethyl acetate). In the case of TiO2, after 1 day of UV irradiation, all organic compounds were removed. Contrary to it, in the case of exfoliated g-C3N4, the concentration of acetone after UV or VIS irradiation increased. The solid-state measurements indicate that after UV/VIS light exposure, there are no changes either in the surface layers or in the bulk of the g-C3N4 photocatalyst. However, based on the observed mass decrease and elemental analysis, the material is oxidised on the surface, and it seems that this surface reaction leads to the disruption of the C–N bonds and the formation of organic compounds, which are released into the atmosphere. But, no compounds containing nitrogen were determined by MS, so nitrogen is most probably released in the form of NOx.

Solubility of Azilsartan in Methanol, Ethanol, Acetonitrile, n-Propanol, Isopropanol, Tetrahydrofuran, and Binary Solvent Mixtures between 293.15 and 333.15 K.

A precise determination method of azilsartan solubility between 293.15 and 333.15 K in several ordinary solvents and some of their aqueous mixtures was established by high-performance liquid chromatography. In all tested solvents, its solubility shows exponential growth with the increase in temperature. This trend is especially pronounced in methanol and ethanol. The order of solubility of azilsartan can be expressed as ethanol > tetrahydrofuran > ethanol/water (8/2, v/v) > methanol > methanol/water (8/2, v/v) > n-propanol > isopropanol > ethanol/Water (5/5, v/v) > acetonitrile. The solubility data of azilsartan were well correlated by the λh model. Moreover, the thermodynamic data including the dissolving enthalpy, entropy, and Gibbs free energy of azilsartan in each solvent were calculated which is crucial to its preparation technology study.

Fabrication of optimized eco-friendly dye-sensitized solar cells by extracting pigments from low-cost native wild plants

The major proportion of dye-sensitized solar cells (DSSCs) fabrication cost is attributed to the pigments. In this study, to increase the performance/cost ratio of DSSCs, we used several wild regional plants of Persian Gulf zone for natural pigment production. At first, the optimum conditions for pigment extraction were obtained for all plants using response surface methodology. The results showed that increasing temperature, as well as extraction time, increased the pigment extraction efficiency while the pH of the solution did not exert a significant effect on the extraction process. Besides, the microwave-assisted method and pure ethanol have the highest extraction efficiency compared to ordinary solvent extraction and water as the extraction method and solvent, respectively. Moreover, all pigments were characterized using circular dichroism, dynamic light scattering, and zeta potential techniques. The results showed that the extracted pigments from Malva verticillata have the highest optical activity while all kinds of pigments tend to make aggregates 12 h after the extraction. Finally, the effectiveness of each pigment was evaluated as a sensitizer in natural DSSCs that fabricated using the doctor blade technique. Based on the photovoltaic results of the DSSCs sensitized with extracted pigments, the open circuit voltage and short circuit current ranged from 0.35 to 0.542 V and 0.802 to 1.702 mA, respectively. The Microwave-assisted Malva verticillata-DSSC owned the highest energy conversion efficiency of 1.702% as well as the comparable open circuit voltage to that of the reference DSSC that made using synthetic sensitizer. This superiority could be attributed to the highest pigments concentration as well as the highest pigments optical activity of Malva verticillata. Moreover, the results showed that the LUMO energy level and the band gap of the extracted pigments from Malva verticillata are better than the other natural pigments for DSSC fabrication. Besides, due to the presence of carbonyl and hydroxyl groups in chemical structures of extracted pigment from Malva verticillata, an effective bond between the pigment and TiO2 surface might be achieved and thereby increasing the energy conversion efficiency.

Double bond carboxylate ionic liquids for reversible SO2 capture

Abstract Solubility of SO2 in [N2224][Met] was measured at temperature from 313.2 to 333.2 K and pressure up to 1.8 bar. The [N2224][Met] absorbed SO2 at high speed and could be recycled for four times. The Reaction Equilibrium Thermodynamic Model (RETM) was used to correlate the experimental data, Henry’s constant (H), reaction equilibrium constant (K0), and thermodynamic properties ( Δ r H m 0 , Δ r G m 0 , Δ r S m 0 , Δ H phy a n d Δ H chem ) were derived. Considering the absorption capacity and low absorption enthalpy, as well as the fast absorption process, [N2224][Met] is thought to be a promising absorbent to ordinary solvent as a desulfurizer.

Functional Design of Ionic Liquids: Unprecedented Liquids that Contribute to Energy Technology, Bioscience, and Materials Sciences

Abstract There are increasing numbers of studies on the design and evaluation of functional ionic liquids (ILs). Recent progress of functional ILs has been reviewed here. Applications of ILs as solvents for hardly-soluble materials in ordinary solvents are discussed mainly from the viewpoint of energy conversion. We focus on a potential application of ILs as electrolyte solution substituents not only for battery but also other electrochemical devices. Also, the uses of ILs as solvents for biomolecules, especially for dissolution of proteins are summarized. Recent progress with zwitterionic ILs and polymerized ILs are also reviewed as unique morphology ILs. Mixtures of molecular liquids and ILs are quite interesting systems, and thermotropic phase change of these mixtures is described including some applications.

Temperature elevation and fluid convection under optical trapping condition as revealed by fluorescence correlation spectroscopy

Temperature of matter increases under intense photoirradiation owing to photothermal conversion. The photothermal effect is sometimes a significant issue in optical manipulation usually requiring intense optical fields. Quantitative evaluation of local temperature under photoirradiation can, therefore, provide indispensable information for optical manipulation. In a previous work, we have applied fluorescence correlation spectroscopy (FCS) to monitor the temperature under the optical trapping condition in water, ethanol, and ethylene glycol. We pointed out that analyses of diffusion time of fluorescent dyes could provide information about temperature on the basis of temperature-dependent viscosities of the solvents. In the present work, the FCS thermometry was applied to seven solvents including primary aliphatic alcohols, to examine universal applicability of the method. To verify the experimental results, numerical simulations were performed on the basis of two-dimensional heat conduction at a stationary state. The numerical results on the temperature field satisfactorily reproduced the experimental data, proving that the FCS thermometry is applicable to ordinary solvents. In addition, we also performed numerical simulations on velocity fields in the solvent, to evaluate contribution of natural convection under typical optical trapping condition at light intensity of ∼MW cm − 2. It was revealed that the contribution of the natural convection is not negligible for mass transfer in the solvents.

Improvement of Laser Processing for Colloidal Silicon Nanocrystal Formation in a Reactive Solvent

We report the highly improvement of colloidal Si nanocrystal (Si-nc) formation by pulsed-UV-laser irradiation of porous silicon in a HF-contained organic solvent. The Si-nc in such reactive organic solvent exhibits higher photoluminescence quantum yield (∼50–70%) than that in an ordinary organic solvent without HF (∼20%). This enhancement of the quantum yield is caused by HF-induced removal of the surface oxidation layer and subsequent hydrogen termination of the Si surface. These reaction kinetics promote an efficient hydrosilylation between the hydrogen-terminated surface and an organic solvent, resulting in oxygen-free surface terminated by alkyl groups. Furthermore, the preparation yield in the HF-contained solvent is higher and the size distribution of Si-nc becomes more homogeneous than those in the ordinary solvent. These results can be attributed to efficient pulsed-laser-induced fragmentation by the removal of the oxidation layer on the porous Si target surface.

Effect Of High Pressure Homogenization (HPH) On The Rheological Properties Of Pineapple Leaf Cellulose/[BMIM]Cl Solution

Due to the intermolecular and intramolecular strong hydrogen bonds, cellulose possesses high crystallinity, hardly dissolves in ordinary solvents. In the meanwhile, the cellulose, hemicelluloses and lignin were woven into compact structure, that is one of the reasons that natural cellulose poorly soluble in water and other organic solvent [1] Swatloski et al in 2002 first explicitly pointed out that ionic liquid, 1 - butyl 3 - methyl imidazole chloride salt ([Bmim]Cl) had good solubility of cellulose. The ionic liquids, with their excellent physical and chemical property, cause more and more concerns of people increasingly [2].You can take advantage of the ionic liquid ([Bmim]Cl) good solubility of cellulose by microwave heating way to dissolve cellulose in ionic liquids [3] [4]. As a new type of high-efficient green solvent, ionic liquid has unique properties, which is different from the traditional solvent. The highly effective and safe homogeneous treatment of pineapple leaf cellulose under microwave irradiation was reported in this paper. The rheological properties of pineapple leaf cellulose / [BMIM]Cl had a great change after the high pressure homogenization (HPH). Effect of high pressure homogenization on the rheological properties of pineapple leaf cellulose / [BMIM]Cl solution was investigated by rotational rheometer MARS III Haake (Germany).

Ionothermal precipitation of highly dispersive ZnO nanoparticles with improved photocatalytic performance

ZnO nanoparticles (NPs) were prepared by an ionothermal precipitation method in a ChCl:DEG deep eutectic solvent using Zn(CH3COO)2·2H2O as a zinc source. A possible mechanism for the ZnO nucleation is discussed. The as-prepared ZnO samples were thoroughly examined by XRD, TEM, SEM, FTIR and XPS. The thermal and optical properties were further characterized by TGA/DTA, UV–vis and PL spectra, respectively. The results show that wurtzite ZnO mono-crystals with an average size of 30±1nm were achieved, and their morphology was expressed as a polyhedron with distorted hexagonal base faces. Furthermore, the DEG molecules were incorporated into the surfaces of the ZnO crystals and could only be removed by thermal annealing; the molecules persisted after washing with ordinary solvents. Dynamic light scattering (DLS) shows that the ZnO NPs modified via DEG molecules are stable in an aqueous suspension without additives. In addition, the inclusion of DEG promotes light absorption at a longer wavelength but reduces the intensity of emissions. XPS reveals that the removal of DEG induced exposed polar surfaces and defects and thus increased the intensity of photoluminescence, especially blue emission. The findings of this work not only provide a facile and environmentally friendly ionothermal method to prepare uniform ZnO NPs protected by DEG but also improve the aqueous suspension stability. Consequently, the photocatalytic performance is enhanced.

Unsaponifiable Matter in Carnuba (&amp;lt;i&amp;gt;Cera carnuba&amp;lt;/i&amp;gt;) Wax, a Modification of the USP/NF and FCC Methods

Carnuba wax consists chiefly of myricyl cerotate (MW 817.4) and small quantities of free cerotic acid (C26H52O2, Mw 396.7) and myricyl alcohol (C30H62O, mp 90°C). Of the two common extraction solvents, ethyl ether or petroleum ether, Lewkowitsch prefers the former. Concerning separation of phases, he advocates addition of small amounts of alcohol or caustic, and he also states that formation of a flocculant layer between the aqueous layer and the solvent does not interfere with the correct estimation of the unsaponifiable matter. These statements were not corroborated in the hands of this chemist. The “Unsaponifiable Matter” in oils or and fats, which consist mainly of hydrocarbons, sterols and aliphatic alcohols of high molecular mass that are not saponifiable by alkali hydroxides but are soluble in the ordinary fat solvents, and to products of saponification that are soluble in such solvents. Carnuba wax, a rather expensive wax, may be adulterated with less expensive paraffin by dishonest merchants. ASTM has a method for determining paraffinic material in carnuba wax. It uses heptanes at its boiling point to dissolve the wax, apply it to a silica gel column, and elute only the nonpolar (i.e. alkane) material. The method has the disadvantage of using a large volume of haptane, nor is it called for by either US Pharmacopeia/National Formulary (USP/NF) or Food Chemicals Codex (FCC). The test for unsaponifiable matter on pure carnuba wax will yield a result of 50.0% - 55.0%, while a higher result will betray the presence of paraffin adulterants.

Macroscopic Alignment of Cylinders via Directional Coalescence of Spheres along Annealing Solvent Permeation Directions in Block Copolymer Thick Films

We reported the long-range perpendicular and horizontal orientation of polystyrene cylinders in polystyrene-b-poly(methyl acrylate) (PS-b-PMA) films with thickness scale from hundreds micrometers to millimeters. Dissolving block copolymer (BCP) in selective solvents forms PS micelles in solution, which could be trapped in films after ordinary solvent casting. Controllable alignment of perpendicular and horizontal cylinders from the directional coalescences of PS spheres along permeation directions of annealing solvent into the film was achieved, i.e., solvent permeating from surface of film led to perpendicular PS cylinders while from edge resulted in horizontal cylinders. Polarizing optical micrographs and μ-beam SAXS confirmed the directional coalescences mechanism during the orientation process and that the cylindrical structure was achieved throughout a macroscopic scale. Solvent components influenced the orientation behavior, and the mixed solvents containing 25–40% (volume fraction) methanol were favorable to form highly oriented cylinders.

ChemInform Abstract: (PhIO)n Mediated Annulations of Aromatic Aldehyde N‐Acylhydrazones for the Synthesis of 1,3,4‐Oxadiazoles.

Oxadiazole as a class of five-membered heterocycles has been reported to be biologically versatile compounds due to their metabolic profile. Amongst these heterocycles, 1,3,4oxadiazole has become an important construction motif for the development of new drugs, furamizole as antibiotics, tiodazosin as antihypertensive agent and raltegravir as antiretroviral agent have been on market. In addition, 2,5-disubstituted-1,3,4-oxadiazole derivatives have also been used as electron conducting and hole blocking (ECHB) materials for electron deficient and good electron transport properties of oxadiazole rings. The most common synthetic approach to 1,3,4-oxadiazoles involves cyclodehydration of 1,2-diacylhydrazines 3 (Scheme 1). Typically, this reaction is carried out by using SOCl2, 5 POCl3, 6 as well as others. Although these methods are very useful for the preparation of large quantities of materials due to the ready availability of diacylhydrazines, hydrazides, and hydrazones as starting materials, the reaction conditions tend to be harsh and long reaction times are generally needed. An alternative route to 1,3,4-oxadiazoles 2 by oxidative cyclization from the corresponding aldehyde N-acylhydrazones 1 proceeds (a) with transition metal oxidants such as Pb, Mn, Fe, Ce or Cu et al.; (b) with chloramine T, Trichloroisocyanuric Acid, iodobenzene diacetate (IBD), Dess–Martin reagent (DMP) or other oxidants; (c) electrochemical methods (Scheme 1). To the best of our knowledge, preparation of 1,3,4-oxadiazoles utilizing iodosobenzene as the oxidizing agent has not been reported yet. In our continuous research program of the oxidation of hypervalent iodine, we were interested in the development of robust and general method to access functionalized 2,5-disubstituted-1,3,4-oxadiazoles. It was found that aromatic aldehyde N-acylhydrazones 1 reacted with (PhIO)n/BF3·Et2O at room temperature to efficiently afford 2,5-disubstituted-1,3,4-oxadiazoles 2 in mild to good yields (Scheme 2). The polymeric character of iodosobenzene makes it less suitable as oxidant than other hypervalent reagents, mainly because of its insolubility in ordinary solvents. Its utility is, however, greatly enhanced when it is used with catalysts, notably boron trifluoride. The electrophilic character of iodine in iodosobenzene is greatly increased by the addition of boron trifluoride, probably because of the in-situ formation of the monomeric dipole PhI+-OBF3 −. N'-Benzylidenefuran-2-carbohydrazide (1a) was chosen as the substrate in initial studies (Table 1). When the substrate

(PhIO)nMediated Annulations of Aromatic Aldehyde N-Acylhydrazones for the Synthesis of 1,3,4-Oxadiazoles

Oxadiazole as a class of five-membered heterocycles has been reported to be biologically versatile compounds due to their metabolic profile. Amongst these heterocycles, 1,3,4oxadiazole has become an important construction motif for the development of new drugs, furamizole as antibiotics, tiodazosin as antihypertensive agent and raltegravir as antiretroviral agent have been on market. In addition, 2,5-disubstituted-1,3,4-oxadiazole derivatives have also been used as electron conducting and hole blocking (ECHB) materials for electron deficient and good electron transport properties of oxadiazole rings. The most common synthetic approach to 1,3,4-oxadiazoles involves cyclodehydration of 1,2-diacylhydrazines 3 (Scheme 1). Typically, this reaction is carried out by using SOCl2, 5 POCl3, 6 as well as others. Although these methods are very useful for the preparation of large quantities of materials due to the ready availability of diacylhydrazines, hydrazides, and hydrazones as starting materials, the reaction conditions tend to be harsh and long reaction times are generally needed. An alternative route to 1,3,4-oxadiazoles 2 by oxidative cyclization from the corresponding aldehyde N-acylhydrazones 1 proceeds (a) with transition metal oxidants such as Pb, Mn, Fe, Ce or Cu et al.; (b) with chloramine T, Trichloroisocyanuric Acid, iodobenzene diacetate (IBD), Dess–Martin reagent (DMP) or other oxidants; (c) electrochemical methods (Scheme 1). To the best of our knowledge, preparation of 1,3,4-oxadiazoles utilizing iodosobenzene as the oxidizing agent has not been reported yet. In our continuous research program of the oxidation of hypervalent iodine, we were interested in the development of robust and general method to access functionalized 2,5-disubstituted-1,3,4-oxadiazoles. It was found that aromatic aldehyde N-acylhydrazones 1 reacted with (PhIO)n/BF3·Et2O at room temperature to efficiently afford 2,5-disubstituted-1,3,4-oxadiazoles 2 in mild to good yields (Scheme 2). The polymeric character of iodosobenzene makes it less suitable as oxidant than other hypervalent reagents, mainly because of its insolubility in ordinary solvents. Its utility is, however, greatly enhanced when it is used with catalysts, notably boron trifluoride. The electrophilic character of iodine in iodosobenzene is greatly increased by the addition of boron trifluoride, probably because of the in-situ formation of the monomeric dipole PhI+-OBF3 −. N'-Benzylidenefuran-2-carbohydrazide (1a) was chosen as the substrate in initial studies (Table 1). When the substrate

ChemInform Abstract: Actinide Chemistry in Ionic Liquids

AbstractReview: emphasis on uranium; 72 refs.

Actinide Chemistry in Ionic Liquids

This Forum Article provides an overview of the reported studies on the actinide chemistry in ionic liquids (ILs) with a particular focus on several fundamental chemical aspects: (i) complex formation, (ii) electrochemistry, and (iii) extraction behavior. The majority of investigations have been dedicated to uranium, especially for the 6+ oxidation state (UO2(2+)), because the chemistry of uranium in ordinary solvents has been well investigated and uranium is the most abundant element in the actual nuclear fuel cycles. Other actinides such as thorium, neptunium, plutonium, americium, and curiumm, although less studied, are also of importance in fully understanding the nuclear fuel engineering process and the safe geological disposal of radioactive wastes.

Fundamental Investigation of Polymer Dynamics with Dielectric and Viscoelastic Methods

This paper briefly summarizes two representative examples of investigation of fundamental polymer dynamics with dielectric and viscoelastic methods: 1) Entangled dynamics of flexible polymers: For type-A polymers having the electrical dipoles parallel along the chain backbone, the entanglement dynamics is differently reflected in the dielectric and viscoelastic relaxation functions. A simple relationship between these functions was deduced for the case of full dynamic tube dilation (full-DTD). This full-DTD relationship was found to hold experimentally for monodisperse linear chains, but not for branched (star and Cayley-tree) chains and linear/linear blends. A refined relationship, referred to as partial-DTD, was developed by taking into account the time necessary for constraint release equilibration. This partial-DTD relationship was found to valid for the linear, branched, and blend systems. 2) Effect of carbon dioxide (CO2) on polymer dynamics: Pressurized CO2 dissolves into polymers to exhibit a plasticizing effect. Dielectric tests revealed that the local dynamics of polymer chains was accelerated by pressurized CO2 without changing relaxation mode distribution. This unusual plasticizing effect of pressurized CO2 for the local dynamics was attributed to extraordinary fast diffusion of CO2 compared to the segmental motion of the polymer chain. The concentration fluctuation of the polymers, being responsible for the relaxation mode broadening usually observed for plasticized polymer systems, is smeared by the fast CO2 molecules in the time scale of segmental motion. In contrast, pressurized CO2 behaves just as an ordinary solvent for the slow, global dynamics of polymer chains.