Density, Pore Size and Volume

Density Measurement:

Density specifies how much of a substance occupies a defined volume at a stated temperature and pressure. The density of a substance can be used to define the substance and it performance character.

Controlling the density of finished goods is often desirable for performance as well as economic considerations. For this reason, many manufacturers strive to develop materials that are partially porous yet still fulfill their function while others seek an end product of maximum density.

In the manufacture of foams, density is a function of the chemistry used to produce the foam, of additives used to increase the density, and of any additives used to improve the combustion resistance properties of the foam.

Accurate density measurements are an important part of characterizing the physical properties of ceramics. Density is used to determine the desired performance of parts created using Additive Manufacturing. It is also a key element utilized in Pharmaceutical Roller Compaction operations and can be used as an indicator of tablet strength and dissolution.

Density influences the overall quality of manufactured products and density measurements guide the manufacturing process. For this reason, Micromeritics gas pycnometers (AccuPyc and GeoPyc) are used worldwide to characterize raw materials as well as to determine the density of finished products.

Pore Size and Volume by Mercury Porosimetry:

The porosity of a material affects its physical properties and, subsequently, its behavior in its surrounding environment. The term “porosity” is often used to encompass the measurements of pore size, volume, distribution, density, and other porosity-related characteristics of a material. The adsorption and permeability, strength, density, and other factors influenced by a substance’s porosity determine the manner and fashion in which it can be appropriately used.

The AutoPore IV is a high-pressure mercury intrusion porosimeter that provides extremely accurate, fully automated porosity measurements with a high dynamic range, and is suitable for a wide variety of applications. Mercury Porosimetry routinely is applied over a capillary diameter range from 0.003 to 360 μm (five orders of magnitude). This would be equivalent to using the same tool to measure accurately and precisely both the height of a 30-story building and the diameter of a grain of sand.

AccuPyc II 1340

AccuPyc II 1340 - Gas Displacement Pycnometry System:

Gas pycnometry is recognized as one of the most reliable techniques for obtaining true, absolute, skeletal, and apparent volume and density. This technique is non-destructive as it uses the gas displacement method to measure volume. Inert gases, such as helium or nitrogen, are used as the displacement medium. Density calculations using the gas displacement method are much more accurate and reproducible than the traditional Archimedes water displacement method.

The AccuPyc II 1340 Series Pycnometers are fast, fully automatic pycnometers that provide high-speed, high-precision volume measurements and true density calculations on a wide variety of powders, solids, and slurries. The instrument completes most sample analyses in less than three minutes without sacrificing accuracy. After analyses are started with a few keystrokes, data are collected, calculations are performed, and results displayed. A minimal amount of operator attention is required.

Operational Advantages:

  • Maintain product integrity with this non-destructive test.
  • Eliminate error with programmable automatic repeat and data acquisition set to your tolerances to comply with your SOPs.
  • Ability to use a variety of gases.
  • Maximize your investment-Adaptive configuration to meet your sample size needs.
  • Low-cost, minimal maintenance, and small footprint.
  • Increase efficiency and compliance with barcoding compatibility.
  • Speed of analysis, accuracy, repeatability, and reproducibility.
  • Versatility of keypad or Windows software operation.
  • Eliminate procedural steps with direct input from an analytical balance.

GeoPyc 1365

The GeoPyc employs a unique displacement measurement technique that uses Dry Flo, a quasi-fluid composed of small, rigid spheres having a high degree of flow-ability. The sample is placed in a bed of Dry Flo which is agitated and gently consolidated about the sample. The GeoPyc collects the displacement data, performs the calculations, and displays or prints the results.

Features:

  • Highly accurate and reproducible results
  • Fast operation in a small benchtop instrument
  • Fully automated data acquisition and reporting
  • Nondestructive analysis maintains sample integrity
  • Intelligent touch panel for ease of operation and reporting

The Technique:

The GeoPyc employs a unique displacement measurement technique that uses Dry Flo, a quasi-fluid composed of small, rigid spheres having a high degree of flow-ability. The sample is placed in a bed of Dry Flo which is agitated and gently consolidated about the sample. The GeoPyc collects the displacement data, performs the calculations, and displays or prints the results.

The GeoPyc automatically determines the volume and density of a solid object by displacement of Dry Flo, a solid medium. The medium is a narrow distribution of small, rigid spheres that have a high degree of flow ability and achieve close packing around the object under investigation. The particles are sufficiently small that during consolidation they conform closely to the surface of the object, yet do not invade pore space.

Operational Features:

The GeoPyc is operated from an intelligent touch screen. Data acquisition and reporting are fully automated for convenient incorporation in LIMS or other data concentrating systems. A variety of sample chambers is available to accommodate a wide range of sample sizes. After the analysis, a light shaking or dusting completely removes the Dry Flo so the samples can be reused or retested.

The GeoPyc has multiple operating modes including full blank, computed blank, and reference solid calibration with variance, which allows you to optimize speed and accuracy for your individual needs. During analysis, indications of progress and preliminary results make it possible to track what is occurring.

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AutoPore V - Mercury Intrusion Porosimetry

The mercury porosimetry analysis technique is based on the intrusion of mercury into a porous structure under stringently controlled pressures. Besides offering speed, accuracy, and a wide measurement range, mercury porosimetry permits you to calculate numerous sample properties such as pore size distributions, total pore volume, total pore surface area, median pore diameter and sample densities (bulk and skeletal).

The AutoPore V Series Mercury Porosimeters can determine a broader pore size distribution more quickly and accurately than other methods. This instrument also features enhanced safety features and offers new data reduction and reporting choices that provide more information about pore geometry and the fluid transport characteristics of your material.

Operational Advantages:

  • Ability to measure pore diameters from 0.003 to 1100 μm*.
  • Controlled pressure can increase in increments as fine as 0.05 psi from 0.2 to 50 psia. This allows detailed data to be collected in the macropore region.
  • High-resolution (sub-microliter) measurement of intrusion/extrusion volumes produces extraordinary precision allowing the Development of tighter sample specifications, improved production processes, and highquality research data.
  • Operates in scanning and time- or rate-of-intrusion equilibrated modes.

  • Real-time diagnostics provide knowledge of an issue before it becomes critical or impairs your analytical results.

  • Collects extremely high-resolution data; better than 0.1 μL for mercury intrusion and extrusion volume.
  • Improved linear motion for high-pressure chamber closure.

DVVA II - Dynamic Void Volume Analyzer

The DVVA® II is a state-of-the-art dynamic void volume analyzer capable of measuring the compressed void volume and density of carbon black powders and with exceptional precision and accuracy.

This instrument can be used to predict the optimal polymer/carbon black ratios in polymer-reinforcing materials, providing an automated alternative to the oil absorption test, while satisfying the requirements of ASTM D7854-16 test method.

Operational Advantages:

  • Meets all requirements of ASTM D7854-14 test method, with the use of two independent load cells.
  • Fully automated instrument control.
  • USB connection to PC.
  • Windows 7 operating environment.

  • Safety features prevent operation until safety barrier is in place.
  • Variable sample size.
  • User-replaceable piston tip.

  • Compression scan results in less than 5 minutes.

  • Automated corrections to data.
  • Exceptional precision.
  • Hydraulic fluid not needed.
  • Ejects compressed sample for further testing.

  • Free of hazardous materials and waste.