Amount Of Carboxymethyl Cellulose Research Articles

Study of Stability of Sesame Oil-In-Water Emulsions Determined using an Optical Analyzer and Measurement of Particle Size and Distribution

The aim of the study was to determine the optimal conditions, that is, the content of sesame oil and the amount of carboxymethylcellulose, to obtain stable dispersion systems. Emulsions were stored under different temperature conditions. For this purpose, six emulsions were prepared and their stability was examined empirically using techniques including particle size analysis, optical microscopy, and the Turbiscan test. The emulsion containing 40 g of oil and 0.6 g of thickener had the highest stability. No destabilizations in whole the range of stored temperature were observed for the emulsion with that composition. Emulsion was stable as well at cool temperature as at extreme environment (40°C). Nowadays, the use of O/W emulsions based on vegetable oil is continuously increasing. To date, sesame oil has been used mainly for direct consumption. The present work indicates a novel possibility for use of sesame oil as the fat base of an emulsion system. Besides, the study gave information about parameters of long-term stability emulsion what is the key in the quality of the dispersion systems. This knowledge is necessary for the industry in order to avoid destabilizing processes occurring in a new product.

Physical properties and antibacterial activity of quaternized chitosan/carboxymethyl cellulose blend films

Antibacterial property of packaging is needed to improve the microbiological safety of foods. The aim of this work was to incorporate various amounts of carboxymethyl cellulose (CMC) into films based on quaternized chitosan (2-N-Hydroxypropyl-3-trimethylammonium chloride chitosan, HTCC) to develop coating for preserving food. The HTCC film and blend films were characterized by Fourier transform infrared spectroscopy, X-ray diffraction measurements, scanning electron microscopy, and thermogravimetric analysis. The effects of CMC content on the physical properties and antibacterial activities of the blend films were investigated. The effect of coating bananas with the films on their preservation was also determined. The results revealed that HTCC and CMC in the blend films interacted by hydrogen bonding. Both of them could be partly miscible. Compared with HTCC100 film, CMC incorporation improved tensile strength, thermostability, and water resistance, however, increased oxygen permeability, and decreased light transmittance and antibacterial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Bananas coated with the HTCC/CMC blend films had longer shelf life than uncoated bananas. CMC incorporation thus evidently reinforced the HTCC film and lowered its WVP. These results suggest that HTCC/CMC blend films can be used as food packaging materials.

Potential effect of increasing the water content in the digestibility of microdiets for fish larvae

This study aimed to find a way for increasing the water content after rehydration of microdiet particles for fish larvae and to assess whether such increase contributes to a better disaggregation and digestion of particles within the gut of gilthead seabream larvae (4–15 days after hatching, dph). Four microdiets were prepared with increasing amounts of carboxymethylcellulose (CMC): 0, 20, 40 and 80 g kg−1. The inclusion of CMC resulted in an effective increase of the hydration capacity of particles. Water content after immersion ranged from 800 g kg−1 in the microdiet without CMC to 900 g kg−1 with 80 g kg−1 CMC. Larvae of different ages were fed during 10 h with these microdiets. The microparticles containing 80 g kg−1 CMC were more degraded in the gut of the younger larvae. No clear differences were observed from 10 dph onwards. Differences in enzymatic activities were not evident except for α-amylase in 6 dph larvae. Gene expression of the enzyme precursors did not show any relation to the water content of microdiets. Overall, the results indicate that increasing the water content up to 900 g kg−1 may enhance the disintegration of food particles within the gut of younger larvae and to a lesser extent affect the response of digestive enzyme activities.

Water redispersible cellulose nanofibrils adsorbed with carboxymethyl cellulose

Cellulose nanofibrils (CNFs) are difficult to redisperse in water after they have been completely dried due to the irreversible agglomeration of cellulose during drying. Here, we have developed a simple process to prepare water-redispersible dried CNFs by the adsorption of small amounts of carboxymethyl cellulose (CMC) and oven drying. The adsorption of CMC onto CNFs in water suspensions at 22 and 121 °C was studied, and the adsorbed amount of CMC was measured via conductimetric titration. The water-redispersibility of dried CNFs adsorbed with different amounts of CMC was characterized by sedimentation test. Above a critical threshold of CMC adsorption, i.e. 2.3 wt%, the oven dried CNF–CMC sample was fully redispersible in water. The morphology, rheological, and mechanical properties of water-redispersed CNF–CMC samples were investigated by field emission scanning electron microscopy, viscosity measurement, and tensile test, respectively. The water-redispersed CNFs preserved the original properties of never dried CNFs. This new method will facilitate the production, transportation and storage, and large-scale industrial applications of CNFs.

Synthesis and characterization of superabsorbent polymer prepared by radiation-induced graft copolymerization of acrylamide onto carboxymethyl cellulose for controlled release of agrochemicals

Superabsorbent polymer (SAP) was synthesized by radiation-induced grafting of acrylamide (AM) onto carboxymethyl cellulose (CMC) in the presence of a crosslinking agent, N,N′-methylenebisacrylamide (MBA). The effects of various parameters, such as dose, the amount of CMC, AM, MBA and ionic strength on the swelling ratio were investigated. In order to evaluate its controlled release potential, SAP was loaded with potassium nitrate (KNO3) as an agrochemical model and its potential for controlled release of KNO3 was studied. The amount of released KNO3 was analyzed by an inductively coupled plasma mass spectrometry (ICP–MS). The results from controlled release experiment agreed very well with the results from swelling experiment. The synthesized SAP was characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The obtained SAP exhibited a swelling ratio of 190g/g of dry gel.

Effect of Sodium Carboxymethyl Cellulose Concentration on the Photophysical Properties of Zinc Sulfide Nanoparticles

The effect of sodium carboxymethyl cellulose (CMC) as capping agent on the optical (photo) and structural (physical) properties of zinc sulfide (ZnS) nanoparticles was studied. The capped nanoparticles were grown by the precipitation technique. The capping ratio of precursor (ZnS) to surfactant (CMC) (vol/vol) considered were 1:1 (sample S1), 1:2 (S2 sample) and 1:3 (sample S3 sample). Analyses carried out include; X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy and photoluminescence studies. SEM analysis revealed particles as agglomerates. The obtained band gap energies of 4.13, 4.20 and 4.27 eV for samples S1, S3 and S2, respectively are blue shifted when compared to the band gap energy of bulk ZnS semiconductor indicating quantum effect. The calculated particle sizes from XRD ( 3.14, 3.73 and 15.7 nm for samples S3, S2 and S1, respectively) and effective mass approximation (3.59, 3.77 and 3.98 nm for samples S2, S3 and S1, respectively) were found to vary with the capping amount, though not monotonically. Capping ZnS with higher amount of CMC provided more stable nanoparticles, although with lower luminescence. The emission peaks of samples S3 and S2 were red-shifted when compared to that of sample S1. At low CMC capping amount, the luminescence was found to be very high and blue shifted due to a greater Research Article British Journal of Applied Science & Technology, 3(4):1228-1245, 2013 1229 participation of surface trap states.

Tuning of thermal properties of sodium acetate trihydrate by blending with polymer and silver nanoparticles

The use of phase change materials (PCMs) is one of the pathways for the storage of temporarily excessive energy from natural sources (solar) and industry for use at a more suitable later time. One of the materials with a high energy storage density is sodium acetate trihydrate (SAT), on which several studies were conducted in order to solve phase segregation and supercooling problems, e.g. by adding polymers and nucleating agents. Here we investigate the effectiveness of adding a polymer blend of carboxymethyl cellulose (CMC) and silica gel to avoid phase segregation, and silver nanoparticles (AgNPs) as nucleating agent. The synthesis of silver nanoparticles was carried out by a green method in CMC as a way to ensure compatibility with SAT. The addition of AgNPs in higher concentrations to 0.5% reduces supercooling, and mixing silica gel with CMC to avoid segregation phase, yields an increment in the stability of the phase change behavior, during heating and cooling cycles. The latent heat release upon crystallization of the PCM was optimum for the mixture with 0.5% AgNPs, and for the highest amounts of CMC with respect to silica gel, with nearly 95% of latent heat recovery compared to pure SAT.

Preparation of CMC-modified melamine resin spherical nano-phase change energy storage materials

A novel carboxymethyl cellulose (CMC)-modified melamine-formaldehyde (MF) phase change capsule with excellent encapsulation was prepared by in situ polymerization. Effects of CMC on the properties of the capsules were studied by Fourier transformation infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electronic microscopy (SEM), X-ray diffractometry (XRD), and thermogravimetric analysis (TGA). The results showed that the CMC-modified capsules had an average diameter of about 50nm and good uniformity. The phase change enthalpy of the capsules was increased and the cracking ratio decreased by incorporating a suitable amount of CMC. The optimum phase change enthalpy of the nanocapsules was 83.46J/g, and their paraffin content was 63.1%. The heat resistance of the capsule shells decreased after CMC modification. In addition, the nanocapsule cracking ratio of the nanocapsules was 11.0%, which is highly attractive for their application as nano phase change materials.

Thermosensitive methyl cellulose-based injectable hydrogels for post-operation anti-adhesion

Thermosensitive methyl cellulose (MC)-based injectable hydrogels for post-operation anti-adhesion were prepared by integrating polyethylene glycol (PEG), carboxymethyl cellulose (CMC) and chitosan sulfate (CS-SO3) with MC sols. The viscosity of the MC-based sols depended on the sol composition, especially the amount of CMC. The gelation temperature of the sols was tuned by adjusting the concentrations of K+ and other components to obtain an MC-based sol that transformed to a gel at body temperature. The composition of the sol also affected the gel strength. Adding PEG decreased the repulsions between the CMC and CS-SO3 macromolecules and thus increased the gel strength. The efficacy of the MC-based injectable hydrogels as barriers for reducing postsurgical adhesions was evaluated using a rat cecal abrasion model. The PEG and CS-SO3 loaded MC-based injectable hydrogels were effective in reducing adhesion formation and reduced adhesiolysis difficulties.

Effect of Carboxymethylcellulose on Plasticized Polylactide

Polylactide (PLA) was plasticized by two types of plasticizers, glycerol and triacetin. These plasticized PLA were mixed with carboxymethylcellulose (CMC). It was found that with only small amount of CMC, 4.5 wt%, it is effectively to lower glass transition, cold crystallization and melting temperatures of glycerol-plasticized PLA (PLA-g) but not much affected on tensile properties. Moreover, increasing amount of CMC twice could not much affect thermal properties but largely reduced tensile strength, modulus and elongation. The melt flow index of the PLA-g increased largely with the amount of CMC. When 4.5 wt% CMC was added to the glycerol-triacetin plasticized PLA, only glass transition temperature became lower than that of 4.5 wt% CMC filled PLA-g but melting temperature and crystallinity were rather increased with poorer mechanical properties. Increasing amount of CMC tended to enhance melting temperature but still rather poor mechanical properties and high melt flow index. So, the CMC had strong positive effect on melt and negative effect on solid properties of plasticized PLA.

A simple recipe for direct writing complex 45S5 Bioglass® 3D scaffolds

Direct-writing fabrication techniques, such as robocasting, have been ignored up to date for the production of scaffolds from 45S5 Bioglass®, probably due to difficulties in the preparation of stable high solids loading colloidal suspensions (inks) from 45S5 Bioglass® powders using traditional approaches. Here, we report how these difficulties can be overcome. Aqueous suspensions containing 45vol% of 45S5 Bioglass® were successfully prepared using carboxymethyl cellulose (CMC) as single multifunctional (dispersant, binder, gelation agent) processing additive. Playing with the molecular weight (MW) and amount of CMC enabled tuning the rheological properties of the inks to meet the stringent requirements of robocasting. An incomplete surface coverage allowing bridging flocculation to occur is the key to obtain highly performing inks.

Effect of rheology controller agent addition to Micro-Porous Layers on PEMFC performances

Formulations of carbon-based inks for doctor blade applications were considered and the use of Carboxymethylcellulose (CMC) as rheology modifier and suspension stabilizer was proposed. Rheological measurement evidenced that CMC addition guarantees a good dispersion of the carbon powder which results in a higher stability of the ink. The electrical performances of Gas Diffusion Layer (GDL) coated with Micro-Porous Layers (MPLs) prepared with and without CMC were compared. A single PEMFC was used to assess the properties of these GDLs: electrochemical performances were tested in terms of I–V curves and of AC Electrochemical Impedance Spectroscopy (EIS) of the running cell. CMC-containing GDLs showed improved performances when the cell was operated at 80°C and RH 80–60. Analysis of the EIS spectra demonstrated that, at high Current Density (CD), the CMC-based GDLs suffer for water management. Such a behavior was ascribed to a hydrophilic character of the GDL due to residual amounts of CMC in MPL coating.

Nanostructured BiVO4 photocatalysts synthesized via a polymer-assisted coprecipitation method and their photocatalytic properties under visible-light irradiation

Nanostructured BiVO4 photocatalysts were synthesized by a coprecipitation process in the presence of sodium carboxymethylcellulose (CMC), which acts as a steric stabilizer during the formation and growth of the BiVO4 nanoparticles. Samples with different contents of CMC were prepared in order to study the effect of the polymer on the final morphology of the oxide. The synthesized samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), and adsorption-desorption isotherms (BET). The presence of CMC during the first stage of BiVO4 synthesis, promoted the formation of granular particles controlling its morphology and favoring its dispersion. The BiVO4 monoclinic polymorph (m-BiVO4) was obtained free of the tetragonal crystalline form (t-BiVO4) by annealing at different temperatures, which were influenced by CMC content: 400 °C (0.5 wt %), 450 °C (3.0 wt %), and 350 °C (6.0 and 9.0 wt %). BiVO4 nanoparticles showed photocatalytic activity, as they bleached an aqueous solution of rhodamine B (rhB) under visible-light irradiation. The photocatalytic activity of the BiVO4 samples was directly correlated with the amount of CMC added during the synthesis process.

Preparation and Structural Characterization of CMC/MMT Nanocomposite

Using montmorillonite (MMT) and sodium carboxymethylcellulose (CMC) as raw materials, CMC/MMT nanocomposites were prepared by the solution intercalation technique. The microstructures of MMT before and after being intercalated were characterized by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). The results of XRD showed that when the adding amount of CMC increased from naught to 70wt%, the structures of MMT have no change basically; when the adding amount of CMC increased to 80wt%, the decrease of MMT (001) was significant; when the adding amount of CMC reached to 90wt%, the diffraction peak of (001) disappeared, which indicated that the layers of MMT have been exfoliated along (001) and the CMC/MMT intercalated structure has been obtained. The observations by HRTEM showed that the shapes of MMT are layer aggregation or agglomerated particles. The MMT added with 90wt% CMC has changed into intercalated structure with alternating MMT and CMC order mainly, and the intercalated structure was characterized at the atomic scale.

A novel pH‐ and thermo‐sensitive PVP/CMC semi‐IPN hydrogel: Swelling, phase behavior, and drug release study

AbstractPoly(N‐vinyl‐pyrrolidone) (PVP) hydrogel has been considered as a very interesting and promising thermosensitive material. The most vital shortcoming of PVP hydrogel as thermosensitive material is that it does not exhibit thermosensitivity under usual conditions. In this work, semi‐interpenetrating polymer network (semi‐IPN) hydrogels based on PVP and carboxymethylcellulose (CMC) were prepared. The volume phase transition temperature (VPTT) of the hydrogels was determined by swelling behavior and differential scanning calorimetry (DSC). The results showed that the VPTT was significantly dependent on CMC content and the pH of the swelling medium. The amount of CMC in the semi‐IPN hydrogels was 0.050, 0.075, and 0.100 g, the VPTT in buffer solution of pH 1.2 was 29.9 °C, 27.5 °C and 24.5 °C, respectively. In addition, the VPTT occurred in buffer solution of pH 1.2, but did not appear in alkaline medium. Bovine serum albumin (BSA) as a model drug was loaded and the in vitro release studies were carried out in different buffer solutions and at different temperatures. The results of this study suggest that PVP/CMC semi‐IPN hydrogels could serve as potential candidates for protein drug delivery in the intestine. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1749–1756, 2010

In vitro drug release studies of polymeric freeze-dried wafers and solvent-cast films using paracetamol as a model soluble drug

Drug dissolution and release characteristics from freeze-dried wafers and solvent-cast films prepared from sodium carboxymethylcellulose (CMC) have been investigated to determine the mechanisms of drug release from the two systems. The formulations were prepared by freeze-drying (wafers) or drying in air (films), the hydrated gel of the polymer containing paracetamol as a model soluble drug. Scanning electron microscopy (SEM) was used to examine differences between the physical structure of the wafers and films. Dissolution studies were performed using an exchange cell and drug release was measured by UV spectroscopy at 242 nm. The effects of drug loading, polymer content and amount of glycerol (films) on the release characteristics of paracetamol were investigated. The release profiles of paracetamol from the wafers and films were also compared. A digital camera was used to observe the times to complete hydration and dissolution of the wafers containing different amounts of CMC and how that impacts on drug release rates. Both formulations showed sustained type drug release that was modelled by the Korsmeyer–Peppas equation. Changes in the concentration of drug and glycerol (films) did not significantly alter the rate of drug release while increasing polymer content significantly decreased the rate of drug release from both formulations. The results show that the rate of paracetamol release was faster from the wafers than the corresponding films due to differences in their physical structures. The wafers which formed a porous network, hydrated faster than the more dense and continuous, (non-porous) sheet-like structure of the films.

Analysis of CMC attachment onto cellulosic fibers by infrared spectroscopy

Infrared spectroscopy has been used to measure the amount of carboxymethyl cellulose (CMC) attached to cellulosic fibers. CMC was attached to an unbleached kraft pulp in aqueous conditions. Isotropic handsheets were then prepared and ATR spectroscopy was used to measure the intensity of the carboxyl vibration, which correlates to the amount of attached CMC that was determined using a wet chemical approach. The ATR method is rather time consuming as several measurement points on the sample have to be averaged, although it is still much faster than the wet chemical approach. Infrared reflection absorption spectroscopy (IRRAS) using polarized light was further used to measure the amount of attached CMC. In this method the intensity of an electromagnetic wave confined to the thin layer is used to correlate the spectroscopy to the amount of CMC on the fiber surface in the paper sample. The measurement time is shorter than with the ATR method. The proposed IRRAS method could be employed as a fast and reliable way to quantify adsorption of chemicals on pulp fibers.

Influence of molecular weight and degree of substitution of carboxymethylcellulose on the stability of acidified milk drinks

The influence of molecular weight ( M w, 250,000, 700,000) and degree of substitution (DS, 0.7, 0.9 and 1.2) of carboxymethylcellulose (CMC) on the diameter and ζ-potential of casein micelles during acidification in diluted dispersions and on the stability of acidified milk drinks was investigated. The experimental results suggested that CMC with high M w or low DS would result in thick adsorbed layer onto casein micelles. The ζ-potential of CMC-coated casein micelle increased with increasing the M w of CMC with the same DS while at a fixed M w the ζ-potential for CMC with high DS (1.2) increased in comparison with those for CMC with low DS (0.7 and 0.9). Both M w and DS of CMC influenced the stability of acidified milk drinks. CMC with high M w increased the viscosity of acidified milk drinks significantly and therefore contributed to the stability. CMC with high DS resulted in high ζ-potential of CMC-coated casein micelles, increasing the electrostatic repulsion between casein particles, which prevented the phase separation in acidified milk drinks. It was also found that the amount of CMC needed for efficient coverage of casein micelles increased with increasing the M w of CMC. Above the efficient coverage concentration, the long-term stability of acidified milk drinks with high M w CMC was better than that with low M w CMC.

Topochemical modification of cotton fibres with carboxymethyl cellulose

Adsorption of carboxymethyl cellulose (CMC) as a method to introduce charged (ionizable) groups onto cellulose cotton fibre surfaces was investigated. The method was based on application of a previously published method used for wood fibres. The amount of adsorbed ionizable groups was determined indirectly by analysis of CMC in solution by the phenol–sulphuric acid method and directly by conductometric titration of the fibres. Results from the two methods correlated well. The molecular weight and purity of the CMC had an influence on its adsorption onto cotton; high molecular weight CMC was preferentially adsorbed. The adsorbed charge correlated linearly with the amount of CMC adsorbed. The total charge of the cotton fibres could be increased by more than 50% by adsorption of CMC. It is expected that this modification procedure can be used in a wide spectrum of practical applications.

Preparation of 5A zeolite monolith granular extrudates using kaolin: Investigation of the effect of binder on sieving/adsorption properties using a mixture of linear and branched paraffin hydrocarbons

A zeolite monolith extrudates using kaolin is synthesized, and effect of binders on sieving/adsorption properties of the prepared zeo- lite is reported. The monolith extrudates of 4A zeolite powder produced as the precursor of 5A zeolite in the first stage of synthesis pro- cess was prepared using different percentages of kaolin powder and carboxymethylcellulose (CMC) as binding agent. The average particle size distribution of produced 4A zeolite was between 20 and 40 US standard mesh sizes equivalent to 0.841 mm and 0.420 mm, respectively. The extrudate was calcined at 600 � C, and the kaolin content of extrudates was converted to type A zeolite through ion exchange by immersing the extrudates in caustic soda solution. The 4A zeolite extrudate samples were converted to 5A type through ion exchange process using calcium chloride solution. The 5A zeolite samples were characterized using XRD, SEM, and EDX instrumental analytic methods. Sieving test was carried out using samples of 5A zeolite and a special cut of kerosene containing C10-C13 saturated hydrocarbons using a simple dead-end fixed bed. Results show that the highest purity of 5A zeolite, highest rate of calcium ion exchange, and best sieving results are obtained when 30 wt% of binder (kaolin) is used, and use of small amounts of CMC as an organic binder along with inorganic kaolin binder has a pro- found effect on the adsorption properties of the synthesized 5A zeolite. This profound effect is attributed to de-clogging of the cylindrical pores due to CMC gasification in final calcinations of the extrudates.