Water adsorption isotherms of carboxymethyl cellulose, guar, locust bean, tragacanth and xanthan gums

Torres, M.D.; Moreira, Ramón; Chenlo, F.; Vázquez, María J.

doi:10.1016/j.carbpol.2012.03.055

Cited by 124 publications

(87 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…With the exception of PVP, all of the powders showed s-shaped adsorption isotherms indicating type II isotherms. This type of isotherm has also been reported in the literature for these powders (8,9,14,(25)(26)(27). PVP showed a type III isotherm with the moisture content increasing very rapidly at high air humidities; Oksanen and Zografi (6) also reported a type III isotherm for PVP.…”

Section: Discussionsupporting

confidence: 76%

See 1 more Smart Citation

The Effect of Moisture on the Flowability of Pharmaceutical Excipients

2013

View full text Add to dashboard Cite

Abstract. The effect of moisture content on flowability of six pharmaceutical powders (microcrystalline cellulose (MCC), hydroxypropyl methylcellulose (HPMC), carboxymethyl cellulose (CMC), polyvinylpyrrolidone (PVP), corn starch, and potato starch) was investigated. Powder flowability was measured using established static techniques and emerging dynamic avalanche behavior measurements. Static techniques did not provide enough resolution to clearly identify changes in flowability due to increasing powder moisture content. Avalanche time and its standard deviation showed that flowability of MCC, CMC, PVP, and potato starch decreased after a critical moisture content, flowability of corn starch increased and flowability did not significantly change for HPMC. The moisture decreased flowability by forming stronger interparticle liquid bridges and increased flowability by acting as a lubricant. The dynamic density of the celluloses and PVP decreased linearly with increasing moisture content as the particles swelled with water. The starches also swelled and decreased in dynamic density, but only after a moisture content corresponding to monolayer coverage of water around the particles was reached. As flowability and dynamic density change with moisture content, to ensure consistent production of high-quality tablets, the moisture content of the powders must be measured and controlled.

show abstract

Section: Discussionsupporting

confidence: 76%

“…The powder must flow easily and uniformly into the tablet dies to ensure tablet weight uniformity and production of tablets with consistent and reproducible properties (11,13,14). Powder flows from the hopper into the tablet dies when gravitational forces become higher than particle-particle interaction forces.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Moisture on the Flowability of Pharmaceutical Excipients

2013

View full text Add to dashboard Cite

show abstract

“…From that point onwards, less favorable bonds of water with the product's surface sites and the formation of multilayers cause a progressive decrease in q in value. A similar behavior was observed by Torres et al (2012) for the adsorption process of guar, locust bean, and xanthan gums.…”

Section: Integral Thermodynamic Propertiessupporting

confidence: 82%

“…Type-OO behavior was observed by Torres et al (2012) for adsorption isotherms of carboxymethyl cellulose, guar gum, locust gum, tragacanth gum, and xanthan gum at different temperatures (20-65 °C). Melo et al (2011) also observed type-OO sorption isotherms for the skin, pulp, and fibrous part of buriti (Mauritia flexuosa).…”

Section: Bg Sorption Isothermsmentioning

confidence: 99%

Thermodynamic properties of Buriti (Mauritia flexuosa) tree gum

Silva

Pena

2018

Food Sci. Technol

View full text Add to dashboard Cite

Moisture adsorption and desorption isotherms from buriti tree gum (BG) were obtained at different temperatures (25 to 55 °C) in a water activity range of 0.1 to 0.9. The isotherms were classified as type OO. The hysteresis loop and moisture of the monolayer decreased as temperature increased and Halsey's equation proved able to predict with good precision the product's sorption isotherms in the conditions studied. BG's isosteric heats of moisture adsorption and desorption were close to the latent heat of vaporization of pure water for moisture levels above 30 g/100 g db and exponentially increased below that level. The enthalpy-entropy compensation theory and the isokinetic relationship were applied and indicated that BG's moisture adsorption and desorption processes are spontaneous. The integral sorption properties indicated that the increase in surface tension at BG's moisture sorption sites was more representative for the desorption process.Keywords: Mauritia flexuosa; isotherm; water sorption; enthalpy; entropy. Practical application:The thermodynamic properties of sorption processes of gum from buriti tree were determined. These parameters are important to establish drying and storage conditions for the product.

show abstract

“…CMC was chosen as it is an abundant, naturally sourced material that displays stronger water adsorption properties than other cellulosic polymers. 11 This actuator is constructed when a glass fiber (120 µm in diameter) is fully immersed into a solution (5 % by mass) of CMC (molecular weight = 2.5 x 10 5 g/mol, Sigma Aldrich, Lot: A0328062 * ), removed, and allowed to dry. The thickness of the CMC on the fiber is determined by the concentration of the CMC solution and the number of dip-coat cycles.…”

mentioning

confidence: 99%

Humidity Responsive Photonic Sensor based on a Carboxymethyl Cellulose Mechanical Actuator

Hartings¹,

Douglass²,

Neice³

et al. 2017

Preprint

View full text Add to dashboard Cite

Abstract:We describe an intuitive and simple method for exploiting humidity-driven volume changes in carboxymethyl cellulose (CMC) to fabricate a humidity responsive actuator on a glass fiber substrate. We optimize this platform to generate a photonic-based humidity sensor where CMC coated on a fiber optic containing a fiber Bragg grating (FBG) actuates a mechanical strain in response to humidity changes. The humidity-driven mechanical deformation of the FBG results in a large linear change in Bragg resonance wavelength over the humidity range of 5 %RH (relative humidity) to 40 %RH. The measurement uncertainty over this range is ± 2 %RH.Introduction: Measurement of humidity refers to a determination of the amount of gaseous water a local the environment. 1-4 Often the water-vapor content is expressed in units of relative humidity (RH) which is simply the ratio of water vapor partial pressure to the saturation water vapor partial pressure at a specific temperature. 1 Like temperature, humidity is an important parameter for controlling the quality of manufactured goods from starting materials to usage across a diverse array of industries including semiconductor and pharmaceutical manufacturing. In the pharmaceutical production and storage, uncontrolled changes in humidity can lead to pseudo-polymorphic transitions 5 of the drug substance resulting in a form of the active ingredient that could have widely different and inappropriate pharmacokinetics. 6 On a more prosaic level, a lack of good humidity control in building HVAC is important for the comfort and well-being of the occupants and in the detection of possible mold-growth conditions. Consequently, humidity sensing, whether based on electrical or optical devices, has drawn considerable interest. Sensing methods encompass direct absorption spectroscopy, cavity ring down spectroscopy, florescence spectroscopy, light attenuation measurements, interferometric interrogation of Fabry-Perot cavities, strain induced shift in Bragg resonances, and refractive index sensing using evanescent coupling of waveguide field. 1,7 Spectroscopic measurements provide the most definitive measurements, 8 but the instrumentation cost, size and complexity can be a hindrance for routine application. Simple fiber-based humidity sensors such as those relying on polyimide-mediated strain transduction in fiber Bragg grating (FBG) sensors provide a cost-effective means for optical detection of humidity over a wide humidity and temperature range. [9][10]

show abstract

Water adsorption isotherms of carboxymethyl cellulose, guar, locust bean, tragacanth and xanthan gums

Cited by 124 publications

References 27 publications

The Effect of Moisture on the Flowability of Pharmaceutical Excipients

The Effect of Moisture on the Flowability of Pharmaceutical Excipients

Thermodynamic properties of Buriti (Mauritia flexuosa) tree gum

Humidity Responsive Photonic Sensor based on a Carboxymethyl Cellulose Mechanical Actuator

Contact Info

Product

Resources

About