Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Water: A Bronsted-Lowry Acid and Base02:30

Water: A Bronsted-Lowry Acid and Base

The reaction between a Brønsted-Lowry acid and water is called acid ionization. For example, when hydrogen fluoride dissolves in water and ionizes, protons are transferred from hydrogen fluoride molecules to water molecules, yielding hydronium ions and fluoride ions:
Determining the pH of Salt Solutions04:08

Determining the pH of Salt Solutions

The pH of a salt solution is determined by its component anions and cations. Salts that contain pH-neutral anions and the hydronium ion-producing cations form a solution with a pH less than 7. For example, in ammonium nitrate (NH4NO3) solution, NO3− ions do not react with water whereas NH4+ ions produce the hydronium ions resulting in the acidic solution. In contrast, salts that contain pH-neutral cations and the hydroxide ion-producing anions form a solution with a pH greater than 7. For...
pH01:24

pH

The potential of hydrogen (pH) is a measure of the acidity or basicity of a water-based solution determined by the concentration of hydronium ions (H3O+). In one liter of pure water at neutral pH, there are 1×10−7 moles of hydronium ions. However, the extensive range of hydronium ion concentrations present in water-based solutions makes measuring pH in moles cumbersome. Therefore, a pH scale was developed to convert moles of hydronium ions into the negative logarithm of the hydronium ion...
Precipitation Gravimetry01:03

Precipitation Gravimetry

Precipitation gravimetry is based on converting an analyte into a sparingly soluble precipitate, which is separated by filtration and weighed. An ideal precipitate should be pure, insoluble, of known composition, and easily filtered from the reaction mixture.
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...
Precipitation and Co-precipitation01:17

Precipitation and Co-precipitation

Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
Volatilization01:10

Volatilization

Volatilization gravimetry is an analytical technique that measures the mass lost due to the volatilization of the substance. This technique is used to estimate the amount of volatile material in a sample. To perform this method, heat a known amount of the sample to a high temperature in a crucible or other suitable vessel. The volatile substance in the sample evaporates, and the vapor is completely expelled from the crucible either by heating the sample or bubbling a stream of inert gas through...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Interparticle Forces of a Native and Encapsulated Metal-Organic Framework and Their Effects on Colloidal Dispersion.

ACS applied materials & interfaces·2021
Same author

Measurement of Forces between Supported Cationic Bilayers by Colloid Probe Atomic Force Microscopy: Electrolyte Concentration and Composition.

Langmuir : the ACS journal of surfaces and colloids·2018
See all related articles

Related Experiment Video

Updated: Jul 19, 2026

Fabricating Degradable Thermoresponsive Hydrogels on Multiple Length Scales via Reactive Extrusion, Microfluidics, Self-assembly, and Electrospinning
12:07

Fabricating Degradable Thermoresponsive Hydrogels on Multiple Length Scales via Reactive Extrusion, Microfluidics, Self-assembly, and Electrospinning

Published on: April 16, 2018

13.9K

Multiscale Quantitative Rheological Analysis of Composition-Temperature Relationships in Borate-Guar Hydrogels.

María J Martín-Alfonso1, Francisco J Martínez-Boza1, Paul F Luckham2

  • 1Pro2TecS-Chemical Process and Product Technology Research Centre, Department of Chemical Engineering, ETSI, Campus de "El Carmen", Universidad de Huelva, Huelva 21071, Spain.

ACS Applied Polymer Materials
|December 18, 2025
PubMed
Summary

Borate-cross-linked guar gum gels lose elasticity and become viscous above 120°C due to cross-link dissociation. A borax threshold defines gel strength, enabling predictive design for high-temperature applications.

Keywords:
activation energyborate-guarcross-linkinghigh temperaturehydrogelrheology

More Related Videos

Thermal Scanning Conductometry TSC as a General Method for Studying and Controlling the Phase Behavior of Conductive Physical Gels
10:01

Thermal Scanning Conductometry TSC as a General Method for Studying and Controlling the Phase Behavior of Conductive Physical Gels

Published on: January 23, 2018

8.0K
Combining Microfluidics and Microrheology to Determine Rheological Properties of Soft Matter during Repeated Phase Transitions
11:38

Combining Microfluidics and Microrheology to Determine Rheological Properties of Soft Matter during Repeated Phase Transitions

Published on: April 19, 2018

8.4K

Related Experiment Videos

Last Updated: Jul 19, 2026

Fabricating Degradable Thermoresponsive Hydrogels on Multiple Length Scales via Reactive Extrusion, Microfluidics, Self-assembly, and Electrospinning
12:07

Fabricating Degradable Thermoresponsive Hydrogels on Multiple Length Scales via Reactive Extrusion, Microfluidics, Self-assembly, and Electrospinning

Published on: April 16, 2018

13.9K
Thermal Scanning Conductometry TSC as a General Method for Studying and Controlling the Phase Behavior of Conductive Physical Gels
10:01

Thermal Scanning Conductometry TSC as a General Method for Studying and Controlling the Phase Behavior of Conductive Physical Gels

Published on: January 23, 2018

8.0K
Combining Microfluidics and Microrheology to Determine Rheological Properties of Soft Matter during Repeated Phase Transitions
11:38

Combining Microfluidics and Microrheology to Determine Rheological Properties of Soft Matter during Repeated Phase Transitions

Published on: April 19, 2018

8.4K

Area of Science:

  • Materials Science
  • Polymer Chemistry
  • Rheology

Background:

  • Borate-cross-linked guar gum gels are widely used industrially.
  • Their thermorheological behavior is poorly understood, limiting high-temperature performance prediction.
  • Understanding gel behavior under thermal stress is crucial for material design.

Purpose of the Study:

  • To characterize the thermorheological properties of borate-guar gum gels.
  • To determine the effect of temperature and borax concentration on gel viscoelasticity.
  • To establish parameters for designing thermoresilient borate-guar gels.

Main Methods:

  • Oscillatory rheometry was used to test guar gum dispersions (0.50 wt %) with varying borax-to-guar ratios (1:1 to 1:8).
  • Measurements were conducted across a temperature range of 25 °C to 140 °C.
  • Time-temperature superposition and Arrhenius analysis were applied to rheological data.

Main Results:

  • Gels transitioned from elastic to viscous behavior above 120 °C due to cross-link dissociation.
  • Time-temperature superposition was valid up to 120 °C, with activation energies for junction relaxation (72-85 kJ mol⁻¹) and modulus decay (-10 to -21 kJ mol⁻¹).
  • A borax concentration threshold (~0.1250 wt %) distinguished weak from strong gel regimes, and flow curves showed temperature-dependent shear-thickening and shear-thinning behaviors.

Conclusions:

  • Thermo-induced dissociation of borate-guar cross-links dictates high-temperature gel behavior.
  • Borax concentration significantly influences gel strength and thermoresilience.
  • The findings enable predictive design of borate-guar gels for demanding thermal environments.