scholarly journals Optimized Loading of Carboxymethyl Cellulose (CMC) in Tri-component Electrospun Nanofibers Having Uniform Morphology

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2524
Author(s):  
Motahira Hashmi ◽  
Sana Ullah ◽  
Azeem Ullah ◽  
Muhammad Akmal ◽  
Yusuke Saito ◽  
...  
Keyword(s):  
Carboxymethyl Cellulose ◽  
Water Solubility ◽  
Continuous Production ◽  
Weight Ratio ◽  
Electrospun Nanofibers ◽  
Water Soluble ◽  
Water Soluble Polymer ◽  
Wide Range ◽  
Aqueous Conditions ◽  
Water Holding

Cellulose is one of the most hydrophilic polymers with sufficient water holding capacity but it is unstable in aqueous conditions and it swells. Cellulose itself is not suitable for electrospun nanofibers’ formation due to high swelling, viscosity, and lower conductivity. Carboxymethyl cellulose (CMC) is also super hydrophilic polymer, however it has the same trend for nanofibers formation as that of cellulose. Due to the above-stated reasons, applications of CMC are quite limited in nanotechnology. In recent research, loading of CMC was optimized for electrospun tri-component polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and carboxymethyl cellulose (CMC) nanofibers aim at widening its area of applications. PVA is a water-soluble polymer with a wide range of applications in water filtration, biomedical, and environmental engineering, and with the advantage of easy process ability. However, it was observed that only PVA was not sufficient to produce PVA/CMC nanofibers via electrospinning. To increase spinnability of PVA/CMC nanofibers, PVP was selected as the best available option because of its higher conductivity and water solubility. Weight ratios of CMC and PVP were optimized to produce uniform nanofibers with continuous production as well. It was observed that at a weight ratio of PVP 12 and CMC 3 was at the highest possible loading to produce smooth nanofibers.

scholarly journals A study of the effects of sodium alginate and sodium carboxymethyl cellulose on the growth of the common duckweed (Lemna minor L.)

2021 ◽  
pp. 82-82
Author(s):  
Bianca Boros ◽  
Nathalie Grau ◽  
Adriana Isvoran ◽  
Adina Datcu ◽  
Nicoleta Ianovici ◽  
...  
Keyword(s):  
Sodium Alginate ◽  
Carboxymethyl Cellulose ◽  
Water Solubility ◽  
Lemna Minor ◽  
Sodium Carboxymethyl Cellulose ◽  
Log P ◽  
Growth Inhibitory ◽  
Wide Range ◽  
The Common ◽  
High Doses

Sodium alginate (ALG) and sodium carboxymethyl cellulose (CMC) are two polysaccharides that have a wide range of applications which could lead to accidental pollution of the environment, making the assessment of their potential ecotoxicity imperative. The present study assesses the ALG and CMC effects on the growth response of the common duckweed (Lemna minor L.). The results emphasize that both polysaccharides can be classified as practically nontoxic based on their EC50 values, with ALG having a relatively higher toxicity compared to CMC. It was also observed that high doses of 1, 5 and 10 mg mL-1 of the two polysaccharides produced growth inhibitory effects against common duckweed. The toxicity of biopolymers against common duckweed, measured as EC50 values, seems to be correlated to the hydrophobicity of the monomers building the polymer. The EC50 values increase linearly with the increase of water solubility (log S) values and decrease linearly with the lipophilicity (log P) values.

Cephalopod Olfaction

2017 ◽  
Author(s):  
Anna Di Cosmo ◽  
Gianluca Polese
Keyword(s):  
Water Solubility ◽  
Community Organization ◽  
Population Level ◽  
Water Soluble ◽  
Ecological Niches ◽  
Marine Animals ◽  
Odour Source ◽  
Wide Range ◽  
Olfactory Organs ◽  
Chemosensory Systems

Within the Phylum Mollusca, cephalopods encompass a small and complex group of exclusively marine animals that live in all the oceans of the world with the exception of the Black and Caspian seas. They are distributed from shallow waters down into the deep sea, occupying a wide range of ecological niches. They are dominant predators and themselves prey with high visual capability and well-developed vestibular, auditory, and tactile systems. Nevertheless, their perceptions are chemically facilitated, so that water-soluble and volatile odorants are the key mediators of many physiological and behavioral events. For cephalopods as well as the other aquatic animals, chemical cues convey a remarkable amount of information critical to social interaction, habitat selection, defense, prey localization, courtship and mating, affecting not only individual behavior and population-level processes, but also community organization and ecosystem function. Cephalopods possess chemosensory systems that have anatomical similarities to the olfactory systems of land-based animals, but the molecules perceived from distance are different because their water solubility is of importance. Many insoluble molecules that are detected from distance on land must, in an aquatic system, be perceived by direct contact with the odour source. Most of the studies regarding olfaction in cephalopods have been performed considering only waterborne molecules detected by the “olfactory organs.” However cephalopods are also equipped with “gustatory systems” consisting of receptors distributed on the arm suckers in octopods, buccal lips in decapods, and tentacles in nautiluses. To date, what is known about the olfactory organ in cephalopods comes from studies on nautiloids and coleoids (decapods and octopods). In the nautiloid’s olfactory system, there is a pair of rhinophores located below each eye and open to the environment with a tiny pore, whereas in coleoids a small pit of ciliated cells is present on either side of the head below the eyes close to the mantle edge.

scholarly journals Carboxymethyl Cellulose Acetate Butyrate: A Review of the Preparations, Properties, and Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Mohamed El-Sakhawy ◽  
Samir Kamel ◽  
Ahmed Salama ◽  
Hebat-Allah Sarhan
Keyword(s):  
Cellulose Acetate ◽  
Carboxymethyl Cellulose ◽  
Solid Dispersions ◽  
Pharmaceutical Research ◽  
Amorphous Solid ◽  
Water Soluble ◽  
Cellulose Acetate Butyrate ◽  
Wide Range ◽  
Poorly Soluble ◽  
Acetate Butyrate

Carboxymethyl cellulose acetate butyrate (CMCAB) has gained increasing importance in several fields, particularly in coating technologies and pharmaceutical research. CMCAB is synthesized by esterification of CMC sodium salt with acetic and butyric anhydrides. CMCAB mixed esters are relatively high molecular weight (MW) thermoplastic polymers with high glass transition temperatures (Tg). CMCAB ester is dispersible in water and soluble in a wide range of organic solvents, allowing varied opportunity to the solvent choice. It makes application of coatings more consistent and defect-free. Its ability to slow down the release rate of highly water-soluble compounds and to increase the dissolution of poorly soluble compounds makes CMCAB a unique and potentially valuable tool in pharmaceutical and amorphous solid dispersions (ASD) formulations.

scholarly journals SPRAY DRYING APPROACH IN PREPARATION AND CHARACTERIZATION OF SOLID DISPERSION OF EPROSARTAN MESYLATE

2021 ◽  
Vol 10 (3) ◽  
pp. 2929-2932
Author(s):  
Sachin N Kothawade
Keyword(s):  
Spray Drying ◽  
Solid Dispersion ◽  
Water Solubility ◽  
Solid Dispersions ◽  
Weight Ratio ◽  
Water Soluble ◽  
Drying Methods ◽  
Scanning Calorimetry ◽  
Dispersion Systems ◽  
Physicochemical Features

Spray drying methods were used to make solid dispersions of the medication Eprosartan Mesylate, which is poorly water-soluble. X-ray Powder diffraction, Fourier transform infrared spectroscopy, and differential scanning calorimetry were used to characterize the products' physicochemical features as well as drug-polymer interactions. Eprosartan Mesylate was shown to be dispersed amorphously in both solid dispersion systems, with a drug to polymer weight ratio of 1:4.The drug and polymer created hydrogen bonds, according to the spectrum data. Both techniques utilized in this investigation enhanced Eprosartan Mesylate solubility. Solid dispersions, on the other hand, performed significantly better, dissolving completely in 5 minutes and at a rate that was about 20 times faster than API within the first 15 minutes. Spray drying is a good way to boost the bioavailability of drugs that are poor water solubility.

scholarly journals IMMOBILIZATION OF COBALT DISULFOPHTHALOCYANINATE ONTO POLYMETHYLOLACRYLAMIDE

2018 ◽  
Vol 61 (8) ◽  
pp. 73
Author(s):  
Galina V. Osipova ◽  
Nadezhda L. Pechnikova ◽  
Tatiana A. Ageeva
Keyword(s):  
Metal Complex ◽  
Water Solubility ◽  
Electronic Absorption Spectra ◽  
Aqueous Media ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Water Soluble ◽  
Water Soluble Polymer ◽  
One Step ◽  
Insoluble Compounds

Different character of usage the porphyrins and their analogs immobilized on carrier polymers stimulates an increased interest in the synthesis and research of physico-chemical properties of porphyrin-polymer immobilizates. In this paper the peculiarities of a synthesis of water-soluble polymer systems containing cobalt disulfophthalocyaninate with the components of a different ratio are described. The methylolation reaction of polyacrylamide to immobilize cobalt disulfophthalocyaninate onto water-soluble carrier polymer has been carried out. It is known that heating polymethylolacrylamide or its solutions leads to the formation of three-dimensional structures with ether and methylene bridges. Therefore, initially the conditions for the preparation of polymethylolacrylamide with preservation of its water solubility were selected. It was found to obtain a water-soluble polymethylolacrylamide, it is necessary that the initial concentration of polyacrylamide in water did not exceed 2% by weight. The immobilization of phthalocyanine metal complex onto the modified polyacrylamide was carried out in two ways. The first is the interaction of the phthalocyanine metal complex with methylated polyacrylamide. The second is functionalization of polyacrylamide and the immobilization of phthalocyaninate metal complex onto the polymer in one-step. The introduction conditions of the cobalt disulfophthalocyaninate introduced influenced the formation of cross-linked structures in the synthesized samples. The introduction of macroheterocycle as a powder was found to promote the formation of insoluble compounds in aqueous media. Therefore, phthalocyanine metal complex was introduced into the system as 1% aqueous solution. The immobilization of the phthalocyanine metal complex onto a carrier polymer has been realized through the formation of hydrogen bonds between the methylol groups of polymethylolacrylamide and sulfo groups of the phthalocyanine metal complex and it was due to coordination interaction between the functional groups of the polymer and metallophthalocyanine as well. The amount of bound cobalt disulfophthalocyanine in the samples was determined by the electronic absorption spectra of the solutions of immobilized phthalocyanine metal complex onto the polymer. The mass content of immobilized cobalt disulfophthalocyaninate onto the polymer in the samples obtained by one-step is greater than in case of the samples obtained in two steps, the ratio of the initial reagents being the same.

scholarly journals Glycol Chitosan: A Water-Soluble Polymer for Cell Imaging and Drug Delivery

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4371 ◽  
Author(s):  
Fengming Lin ◽  
Hao-Ran Jia ◽  
Fu-Gen Wu
Keyword(s):  
Antimicrobial Agents ◽  
Tumor Imaging ◽  
Water Soluble ◽  
Glycol Chitosan ◽  
Water Soluble Polymer ◽  
The Past ◽  
Wide Range ◽  
Microbial Infections ◽  
Functional Biomaterials ◽  
Shed Light

Glycol chitosan (GC), a water-soluble chitosan derivative with hydrophilic ethylene glycol branches, has both hydrophobic segments for the encapsulation of various drugs and reactive functional groups for facile chemical modifications. Over the past two decades, a variety of molecules have been physically encapsulated within or chemically conjugated with GC and its derivatives to construct a wide range of functional biomaterials. This review summarizes the recent advances of GC-based materials in cell surface labeling, multimodal tumor imaging, and encapsulation and delivery of drugs (including chemotherapeutics, photosensitizers, nucleic acids, and antimicrobial agents) for combating cancers and microbial infections. Besides, different strategies for GC modifications are also highlighted with the aim to shed light on how to endow GC and its derivatives with desirable properties for therapeutic purposes. In addition, we discuss both the promises and challenges of the GC-derived biomaterials.

scholarly journals Preparation of PVA Fluorescent Gel and Luminescence of Europium Sensitized by Terbium (III)

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 893
Author(s):  
Yifan Wei ◽  
Zhengquan Fu ◽  
Hao Zhao ◽  
Ruiqi Liang ◽  
Chengyu Wang ◽  
...  
Keyword(s):  
Rare Earth ◽  
Film Formation ◽  
Electronic Configuration ◽  
Rare Earth Ions ◽  
Water Soluble ◽  
Fluorescence Properties ◽  
Hydroxyl Groups ◽  
Water Soluble Polymer ◽  
Quenching Effect ◽  
Wide Range

Polyvinyl alcohol (PVA) gel has a very wide range of applications in agriculture, military, industry, and other fields. As a widely used water-soluble polymer, PVA has good mechanical properties, excellent spinnability, good hydrophilicity, remarkable physical and chemical stability, good film formation, is non-polluting, and exhibits good natural degradation and biocompatibility. It is an ideal gel preparation material. Incorporation of rare-earth elements into PVA polymers can be used to prepare rare-earth luminescent gel materials. Results show that the luminescent efficiency of complexes is mainly related to their structure, ligand substituents, synergists, and the electronic configuration of doped rare-earth ions. Fluorescent gel films were prepared by adding europium, terbium, and europium/terbium co-doped into PVA, and their fluorescence properties were compared and analyzed. It was found that, in addition to the above factors, the sensitization of terbium to europium, and the fluorescence-quenching effect of hydroxyl groups, will influence the fluorescence properties. This has opened a new route for the application of rare-earth materials and may have value in the field of new materials.

scholarly journals Complexation with Random Methyl-β-Cyclodextrin and (2-Hidroxypropyl)-β-Cyclodextrin Enhances In Vivo Anti-Fibrotic and Anti-Inflammatory Effects of Chrysin via the Inhibition of NF-κB and TGF-β1/Smad Signaling Pathways and Modulation of Hepatic Pro/Anti-Fibrotic miRNA

2021 ◽  
Vol 22 (4) ◽  
pp. 1869
Author(s):  
Alina Ciceu ◽  
Cornel Balta ◽  
Hidegard Herman ◽  
Sami Gharbia ◽  
Simona-Rebeca Ignat ◽  
...  
Keyword(s):  
Water Solubility ◽  
Transforming Growth Factor ◽  
Stellate Cell ◽  
Smooth Muscle Actin ◽  
Water Soluble ◽  
Alpha Smooth Muscle Actin ◽  
Wide Range ◽  
Anti Inflammatory ◽  
Tgf Β1

Chrysin (CHR) is a natural flavonoid with a wide range of pharmacological activities, including hepatoprotection, but poor water solubility. By including water-soluble hydroxypropyl (HPBCD) and randomly methylated (RAMEB) β-cyclodextrin, we aimed to increase its biodisponibility and the effectiveness of the antifibrotic effects of chrysin at oral administration. Liver fibrosis in mice was induced in 7 weeks by CCl4 i.p. administration, and afterwards treated with 50 mg/kg of CHR-HPBCD, CHR-RAMEB, and free chrysin. CCl4 administration increased hepatic inflammation (which was augmented by the upregulation of nuclear factor kappa-light-chain enhancer of activated B cells (NF-kB), tumor necrosis factor (TNF)-α, and interleukin 6 (IL-6) and induced fibrosis, as determined using histopathology and electron microscopy. These results were also confirmed by the upregulation of Collagen I (Col I) and matrix metalloproteinase (MMP) expression, which led to extracellular fibrotic matrix proliferation. Moreover, the immunopositivity of alpha-smooth muscle actin (a-SMA) in the CCl4 group was evidence of hepatic stellate cell (HSC) activation. The main profibrotic pathway was activated, as confirmed by an increase in the transforming growth factor- β1 (TGF-β1) and Smad 2/3 expression, while Smad 7 expression was decreased. Treatment with CHR–HPBCD and CHR–RAMEB considerably reduced liver injury, attenuated inflammation, and decreased extracellular liver collagen deposits. CHR–RAMEB was determined to be the most active antifibrotic complex. We conclude that both nanocomplexes exert anti-inflammatory effects and antifibrotic effects in a considerably stronger manner than for free chrysin administration.

Modification of Near-Wall Turbulent Structure in Channel Flow by Dosing a Small Amount of Polymer Solution

2017 ◽  
Author(s):  
Yushi Okamura ◽  
Tomohiro Kurose ◽  
Yasuo Kawaguchi
Keyword(s):  
Velocity Distribution ◽  
Polymer Solution ◽  
Polymer Concentration ◽  
Water Soluble ◽  
Polymer Additives ◽  
Normal Velocity ◽  
Water Soluble Polymer ◽  
Low Speed ◽  
Wide Range ◽  
Near Wall

The phenomenon known as Toms effect can impart viscoelasticity to a water flow when a small amount of water-soluble polymer is added. The resulting viscoelastic fluid generates viscoelastic stress in the flow, dramatically reducing the turbulent stress. In this study, the spatial distribution of velocity is measured using a stereo-PIV method in the streamwise-spanwise plane parallel to the wall. Modification of the near wall turbulence by the polymer solution blown slowly from a permeable wall was investigated by analyzing the velocity distribution acquired by stereo-PIV measurements. Experimental results reveal that streamwise local mean velocity decreases as the dosed polymer concentration increases. The skewness factor at this height shifts from 0 to positive by adding the polymer, which indicates intensified turbulent coherent structure. Moreover, the spatial two-point correlation function calculated from streamwise velocity fluctuations maintains its high correlation with the streamwise direction. It is consistent with the finding from the instantaneous velocity distribution, which shows that the flection of low-speed streaks is suppressed. Next, it is revealed that the normal velocity at the wall for low-speed fluid is decreased dramatically by polymer additives. Moreover, applying the quadrant analysis, it is confirmed that ejection events are suppressed with decreasing normal velocity at the wall. Suppression of ejection motion affects to the turbulence in the log law layer. We conclude that this is one reason that turbulence is suppressed in a wide range of the shear layer by polymer additives present only in the vicinity of the wall.

Crosslinking of Guar and Guar Derivatives

SPE Journal ◽  
2007 ◽  
Vol 12 (03) ◽  
pp. 316-321 ◽  
Author(s):  
Cuiyue Lei ◽  
Peter E. Clark
Keyword(s):  
Polymer Solution ◽  
Critical Concentration ◽  
Polymer Concentration ◽  
Water Soluble ◽  
Solution Behavior ◽  
Water Soluble Polymer ◽  
Important Indicator ◽  
Low Concentrations ◽  
Wide Range ◽  
Overlap Concentration

Summary Crosslinking of guar and guar derivatives has played a major role in improving stimulation of oil and gas wells. While crosslinking has been used for a number of years, many facets of crosslinked systems are still not well understood. Part of the problem is that the traditional methods of determining the properties of crosslinked fluids work well for obtaining the data necessary for treatment design, but yield little insight into the nature of the crosslinked system. A good example of this is found in the development of low polymer concentration crosslinked gels. These gels are important because they lower costs and help to minimize formation damage. In this paper, methods for predicting crosslinkability at low concentrations are reported. The polymer literature is filled with methods for characterizing polymer solutions almost none of which find wide use in the development of crosslinked fracturing fluids. Dawson et al. (2000) first reported that the concentration at which a polymer solution transitions from dilute to semidilute could be used as a method for determining the potential for low concentration crosslinking in guar or guar-derivative solutions. To test this assertion, we have conducted a series of experiments that not only shows that the dilute-semidilute transition concentration is an important indicator for the polymers used in this study, but also presents a framework for exploring the potential of other polymer systems. These experiments show conclusively that low-polymer concentration crosslinking is strongly related to the value of the critical overlap concentration, c*. Both the critical overlap concentration and the critical crosslinking concentration increase in the order guar-3 < CMG < CMHPG < guar < HPG. In addition, we show that the critical crosslinking concentration for the range of polymer-crosslinking systems studied is correlated to the critical overlap concentration (). A strong case is presented for the ability to crosslink at low concentrations is a strong function of the polymer type and a weak function of the crosslinker type. Introduction Water-soluble polymers have been used for a number of years as thickening agents for stimulation fluids. Crosslinking was developed to improve the performance of these materials without increasing polymer concentration. Over the years, a number of different crosslinking agents have been used with success. There are several good discussions of polymer and crosslinking systems available (Economides and Nolte 1989; Gidley et al. 1989), and it is not the purpose of this paper to expand these discussions. Rather, we will approach the problem of crosslinking from the prospective of the molecular or solution properties that control or influence crosslinking. When a water-soluble polymer is hydrated, the viscosity of the resulting solution increases as a function of concentration. Starting at low concentrations and building to high concentrations, the viscosity appears to exhibit an exponential increase. This phenomenon has been studied for a wide range of polymer—solvent systems and seems to be universal. Early work divided the viscosity—concentration curve into two regions (Menjivar 1986; Robinson et al. 1982) that were separated at a critical concentration labeled c*. As the understanding of polymer solution behavior progressed and more sensitive instruments and experimental techniques were developed, the solution behavior was determined to be more complex (Rubinstein and Colby 2003).

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