Dissipative crystallization of sodium salt of deoxyribonucleic acid

Drying patterns of aqueous solutions of sodium salt of deoxyribonucleic acid (NaDNA) were studied on a cover glass, a watch glass, and a Petri glass dish at room temperature. Orientation of the rod-like single crystals of NaDNA molecules in the radial direction was observed especially at low polymer concentrations. The ratios of the size of the broad ring against initial size of the liquid on a cover glass and a watch glass were very small between 0.05 and 0.1 compared with those of the typical polyelectrolytes. Main cause is the compact conformation of NaDNA forming single or double stranded helix structures in the dried film. Microscopic drying patterns were long rods accompanied with the many short rods especially on a cover glass. Thick and short rods and dendritic crystals were fogrmed at the inward and outward areas of the dried films, respectively, on a watch glass and a Petri glass dish. Rod-like and dendritic crystals resembled the distorted hedrite and/or spherulite structures. Dissipative crystallization such as the orientation and accumulation of the single crystals of NaDNA were observed and the importance of the convectional and sedimentation processes was demonstrated during the course of crystallization.     

Drying dissipative structure of sodium salts of hyaluronic acid

Macroscopic and microscopic patterns during the course of dryness of aqueous solution in sodium salts of hyaluronic acid (NaHLA) were observed on a cover glass, a watch glass, and a Petri glass dish. Dendritic and rod-like microscopic patterns, which are similar to those of sodium salts of carboxymethyl cellulose, were observed for NaHLA especially on a cover glass and a watch glass. The microscopic patterns of NaHLA are supported to be originated from the hexose groups of polysaccharides, though the similar dendritic patterns are also observed for some of polynucleotides, sodium salts of deoxyribonucleic acid, and potassium salts of poly (riboadenylic acid), for example. Macroscopic broad ring size decreased substantially from the initial size of liquid and decreased slightly as polymer concentration decreased. These observations are consistent with existence of the rather strong interpolymer affinitive forces during the course of dryness. In the coexistence of sodium chloride, microscopic dendritic patterns grew large especially on a cover glass and a watch glass, which was so often observed for polysaccharides examined hitherto. Drying patterns are clarified to be formed by the successive and cooperative processes of evaporation, convection, sedimentation, and solidification.     

Dissipative crystallization of potassium salt of poly(riboadenylic acid)

Dissipative patterns during the course of dryness of aqueous solution of potassium salt of poly(riboadenylic acid) (KPolyA) in the presence of potassium chloride were studied on a cover glass, a watch glass and a glass dish. Accumulation of KPolyA polymers forming the broad ring area and the drastic change in size and shape of the polymer single crystals depending on the location of the dried film, which are the typical effects of the dissipative crystallization, took place. Polymer crystals formed were spherulites, dendritic and rod-like assemblies, which are composed of the single or double helical chains depending on the pH-value of the initial solution.     

Dissipative crystallization of aqueous mixtures of potassium salts of poly(riboguanylic acid) and poly(ribocytidylic acid)

Drying patterns of aqueous solutions of potassium salts of poly(riboguanylic acid) (KPolyG), poly(ribocytidylic acid) (KPolyC), and their mixtures KPolyG + KPolyC were studied on a cover glass, a watch glass, and a glass dish at room temperature. Accumulation of the polymers forming the broad rings near the outside edge and also in the inner area of the dried film was observed. The fine multiple ring structures formed, which supports the fact that the affinity of the polymer with the substrate is strong. Typical microscopic drying patterns of KPolyG, KPolyC, and KPolyG + KPolyC were spherulites, dendritic long rods, and sword (harberd)-like rods, respectively. The patterns changed depending on the location in the dried film. The dendritic long rods and sword-like rods were assigned to the crystals of double-stranded and/or triple-stranded helices of the G:C and 2G:C complexes. Cross-like drying patterns that originated from the salt-polymer interaction are also observed. The relationship between the polymer complexation of KPolyG + KPolyC systems and the drying patterns is similar to that of KPolyA (potassium salt of poly(adenylic acid)) + KPolyU (potassium salt of poly(uridylic acid)).     

Dissipative crystallization of aqueous solutions of hydroxypropyl cellulose

Drying dissipative structures of aqueous solutions of hydroxypropyl cellulose, their viscosities of 2 wt.% solutions ranging from 2 to 2,000 mPa.s were studied on a cover glass, a watch glass, and a Petri glass dish. The thickness profile of the dried film shows the coexistence of a low round hill and a high broad ring on a cover glass. The broad ring size increased as molecular weight and/or concentration of the polymers increased on a cover glass and a watch glass. Microscopic drying crystal patterns of HPC changed as a function of the distance from the film center, which is one of the typical results of the dissipative crystallization. Rod-like microscopic drying patterns originated in the cholesteric liquid crystalline structures were observed. The rods oriented mainly parallel and in some case perpendicularly to the radial direction of the dried film except the central area, where the rods distributed at random. These orientation effects were significant for low molecular weight samples and in a watch glass.     

Dissipative crystallization of aqueous mixtures of potassium salts of poly(riboadenylic acid) and poly(ribouridylic acid)

Dissipative drying patterns of aqueous mixtures of potassium salts of poly(riboadenylic acid) (KPolyA) and poly(ribouridylic acid) (KPolyU) were studied on a cover glass, a watch glass and a glass dish at room temperature. Accumulation of the polymers forming the broad rings near the outside edge and the inner area of the dried film was observed. The fine multiple ring structures formed when the affinity of the polymer with the substrate is strong. Microscopic drying patterns changed drastically depending on the location in the dried film. Microscopic drying patterns were mainly dendritic long rods and sword (halberd)-like rods. They are assigned to the crystals of double-stranded and triple-stranded helices of the A:U and A:2U complexes, respectively. Cross-like drying patterns are also observed originated from the salt-polymer interaction.     

Dissipative crystallization of sodium salts of poly (d-glutamic acid), poly (l-glutamic acid), and their low molecular weight analogs

Drying dissipative patterns were observed at room temperature on a cover glass, a watch glass, and a Petri glass dish during the course of dryness of aqueous solution of sodium salts of poly (d-glutamic acid), poly (l-glutamic acid), and their low molecular weight analogs, monosodium d-glutamate, monosodium l-glutamate, and monosodium dl-glutamate. The low molecular weight analogs were hygroscopic and their drying patterns were observed in a dry box coexisted with the bags of desiccant. The broad rings, which are the typical macroscopic drying patterns, were observed for all the samples. Optical isomeric effects on the drying patterns were not recognized. Spherulite (or hedrite) and rod-like crystals from the assemblies of helical main chains of the polymers are formed mainly at the inner area from the broad ring (except central area) and the broad ring area, respectively. Coexistence of sodium chloride enhanced the crystal structures by the cooperative interactions between the polymers and the salts. The typical dissipative crystallization such as accumulation, segregation, and orientation effects of crystals were observed in the drying patterns.     

Drying dissipative structures of colloidal crystals of silica spheres coated with polymer brushes of poly(carboxymethyl betaine)

Drying patterns of colloidal crystals of colloidal silica spheres coated with the brushes of zwitterionic poly(carboxymethyl betaine) (SiP-PCMB) and their parent silica spheres (SiP) were studied on a cover glass, a watch glass, and a Petri glass dish. Crystal structures kept the whole process of dryness of the suspensions of SiP-PCMB and SiP. Crystal structures of the dried films of SiP-PCMB were kept stable even when the initial suspensions contained 5 mM of sodium chloride, which is the important role of the excluded volume effects of the shells of the polymer brushes. On the other hand, crystal structures of SiP spheres in the dried films were much unstable and melted in the presence of 5 mM sodium chloride. In the suspension state, colloidal crystallization of SiP-PCMB took place stably by the contribution of the excluded volume effects besides the extended electrical double layers compared with that of SiP spheres, where only the double layer effect contributes to the crystallization. The fractal patterns of the complexation of SiP-PCMB or SiP spheres with sodium chloride were observed microscopically in the dried films. Several kinds of dissipative crystallization such as array and/or accumulation of the crystallites were observed, and the importance of the convectional and sedimentation processes during the course of dryness was demonstrated.     

Drying dissipative structure of sodium dextran sulfate in aqueous solution

Drying dissipative patterns were observed at room temperature on a cover glass, a watch glass, and a Petri glass dish during the course of dryness of aqueous solution of sodium salts of dextran sulfate (NaDSS) having molecular weights of 5000, 36,000 ~ 50,000 and 500,000. These biopolyelectrolytes are one of the typical polysaccharides. The influences of the hexose units upon the macroscopic and microscopic drying patterns are studied. Formation of some ordered structure is observed for NaDSS in high polymer concentrations especially on a cover glass. Broad ring size decreased as polymer concentration decreased and/or its molecular weight increased. Drying patterns are clarified to be formed by the successive and cooperative pattern formation of convection, sedimentation, and solidification.     

Drying dissipative structures of aqueous solution of poly(ethylene glycol) on a cover glass, a watch glass, and a glass dish

Drying dissipative structures of aqueous solution of poly(ethylene glycol) (PEG) of molecular weights ranging from 200 to 3,500,000 were studied on a cover glass, a watch glass, and a glass dish on macroscopic and microscopic scales. Any convectional and sedimentation patterns did not appear during the course of drying the PEG solutions. Several important findings on the drying patterns are reported. Firstly, the crystalline structures of the dried film changed from hedrites to spherulites as the molecular weight and/or concentration of PEG increased. Secondly, lamellae were formed along the ring patterns especially at high concentrations and high molecular weights. The coupled crystalline patterns of the spherulites and the lamellae were observed in a watch glass along the ring structures, supporting the important role of the convection by the gravity during the course of dryness. The coupled patterns were difficult to be formed on a cover glass and a glass dish, except at the outside edge of the dried film. Thirdly, the size of the broad ring at the outside edge of the dried film especially on a cover glass and a watch glass increased sharply as the molecular weight increased and also as the polymer concentration increased. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Sorption and diffusion of water vapour on edible films

Two types of films consisting of sodium salt of carboxymethyl cellulose (NaCMC) and hydroxypropyl cellulose (HPC) as film forming materials and glycerin as plasticizer were prepared, characterized and their water vapour sorption properties were determined. The water sorption isotherms of the films were measured using a magnetic suspension balance. Results show that diffusion of water vapour in NaCMC based film is faster than that in HPC based films, due to the heterogeneous structure and larger pore dimensions of the NaCMC films.     

Drying dissipative structure of similar sized aggregates (1.5 μm in diameter) of nano-sized diamond particles (4 nm in diameter)

Macroscopic and microscopic drying patterns were observed on a cover glass, a watch glass, and a Petri glass dish during the course of dryness of aqueous suspensions of similar sized aggregates of diamonds (CD1), which formed from the deionization of the pre-particles of diamond 4 nm in diameter. Two kinds of macroscopic patterns, i.e., outer and inner broad rings, and spoke lines were formed. Cooperative drying processes of the convection, sedimentation, and solidification were clarified. Microscopic drying patterns showing the formation of very large dendritic aggregates from the CD1 particles were observed only when the excess amount of sodium chloride higher than 2 mM coexisted in the initial suspensions before dryness and further initial CD1 concentration is lower than 0.17 wt%.     

Ionic conductivity enhancement of PVA: carboxymethyl cellulose poly-blend electrolyte films through the doping of NaI salt

Cellulose - In this paper, we report the effect of doping sodium iodide (NaI) salt into a polymer blend matrix of sodium carboxymethyl cellulose (NaCMC) and poly(vinyl alcohol) (PVA). Solution...     

Rheological Properties and Water-Retaining Power of Agar Hydrogels with Carboxymethyl Cellulose

Russian Journal of Applied Chemistry - Rheological properties of composite hydrogels of agar with carboxymethyl cellulose sodium salt (NaCMC), intended for water conservation, were studied. The...     

NaCMC与甲基丙烯酰氧乙基二甲基辛基溴化铵及AM接枝共聚物的性能

水溶性增粘剂;增粘性能;协同增效作用;疏水缔合作用;剪切作用;NaCMC与甲基丙烯酰氧乙基二甲基辛基溴化铵及AM接枝共聚物的性能     

Hydrogels of Gelatin-Sodium Carboxymethyl Cellulose: Synthesis and Swelling Kinetics

Abstract

Hydrogels of gelatin crosslinked with glutaraldehyde and sodium carboxymethyl cellulose (NaCMC) of several compositions were prepared. The swelling kinetics as a function of composition, temperature. pH, and ionic strength was studied. The rate of swelling and equilibrium swelling were found to depend on the NaCMC content in all cases. The equilibrium swelling increased with the temperature. The gels, which were weakly acidic, registered increased swelling at higher pH. Swelling was suppressed in aqueous salt solutions. In agreement with predictions of the Donnan theory, swelling in monovalent salt solutions is greater than in divalent salt solutions.     

Drying dissipative patterns of aqueous solutions of simple electrolytes and their binary mixtures on a cover glass

The drying dissipative patterns of aqueous solutions of simple electrolytes, KCl, NaCl, CaCl₂, and LaCl₃, were observed on a cover glass. The macroscopic broad rings were formed at the outside edge of the drying film area, which shrunk from the initial solution area especially at low salt concentrations. The drying area and the broad ring size decreased as the salt concentration decreased. The microscopic block-like and dendritic cross-like patterns were observed for all the salts. Size of single crystals dried on a cover glass increased as salt concentration increased. The drying patterns of the binary mixtures of the salts were also observed. Size of the broad ring increased sharply by mixing. The microscopic patterns were, on the other hand, insensitive to the mixing.     

Laser flash photolysis and time-resolved fluorescence measurements of the aggregation number of SDS-biopolymer complexes

Aqueous solutions of 0.5% sodium carboxymethyl cellulose, NaCMC, and 2-hydroxyethyl cellulose, HEC, and variable concentration of sodium dodecyl sulfate, SDS, were studied by the intensities ratio of pyrene fluorescence bands (I/III and monomer/excimer) and conductance measurements to determine the critical aggregation concentration, cac, and the degree of micellar dissociation, alpha, respectively. The cac of these systems is close to 2-4 x 10(-3)M and values of alpha are consistent with the formation of SDS micelles adsorbed cooperatively to the polymer backbone. Laser flash photolysis (LFP) and time-resolved fluorescence (TRF) techniques were employed to determine the micellar aggregation number, N, using the probes flavone and pyrene, respectively. The obtained N for HEC/SDS and NaCMC/SDS were 48 and 68, respectively. The presence of the counterions at the NaCMC backbone is the main factor responsible for this number. Besides, the transient spectra of flavone and present in 0.5% HEC or NaCMC with and in absence of SDS are discussed. Flavone triplet state exit rate constant from the biopolymer/SDS complexes showed that these systems are completely different from a pure SDS micelle.     

Reactions catalyzed by soda lime glass. III. Molecular weights of poly(methyl methacrylate) prepared in aqueous media with NaHSO3 as initiator

The polymerization of methyl methacrylate (MMA) was carried out in water by use of various concentrations of sodium bisulfite as initiator in the presence and absence of colorless and colored soda lime glass at 40°C. The reaction products were filtered, washed with water, methanol and finally dried at 50°C. The glass–polymer combination was subjected to Soxhlet extraction with benzene. The molecular weights of the soluble polymers were determined viscometrically. In the absence of glass, the conversion was lower but the average molecular weights were higher than in presence of soda lime glass. The effect of grain size of the glass on conversion and molecular weights was such that larger grain size of glass resulted in lower conversion and higher average molecular weights.     

Dissipative crystallization of aqueous solution of sodium polymethacrylate

Drying dissipative structures of aqueous solution of sodium polymethacrylate (NaPMA) were studied on a cover glass, a watch glass, and a glass dish. Any convectional and sedimentation patterns did not appear during the course of dryness. Several important findings on the drying patterns are reported. Firstly, spherulite and hedrite dissipative crystals were observed when the polymer solutions were dried. The crystalline structures changed from hedrites to spherulites as polymer concentration increased. Secondary, the coupled structures of the spherulites and the broad rings were observed for NaPMA at the outside edge of the broad ring. However, the coupled crystalline structures of the lamellaes from the broad ring and the spherulites, which were observed for poly(ethylene glycol) (Okubo et al. 2009), were not observed clearly for NaPMA system. Thirdly, size of the broad ring at the outside edge of the dried film increased sharply as polymer concentration increased.