The ACORN AREA™ is a revolutionary instrument designed to measure the surface area of nanoparticles dispersed in a liquid. This patented nuclear magnetic resonance method offers many advantages in comparison with conventional surface area techniques.
The relaxation time of particles dispersed in a liquid is an average of the two relaxation times, weighted by the relative amount of liquid on the particle surface and that in the free liquid. This is a direct measure of the particle surface area.
Acorn Area advantages
Measurements without dilution
No sample preparation
Results in minutes
No moving parts
Suitable for QC or R&D
Simple to use
Dedicated software: AreaQuant™
To make a measurement,
Place a 0.5 ml sample in a sample tube.
Insert it into the Acorn Area™. The sample resides within a coil located between two permanent magnets.
A static, uniform magnetic feld, B0, causes the protons within the liquid to align with B0; this process typically takes a few seconds.
Interface: PC ou PDA via USB
Power: 100-240 VAC 50/60 Hz, 3 ampères
L x l x H: 240 x 360 x 160 mm
Weight: 7 kg
ACORN AREA Particle surface area
ACORN AREA™ is delivered with its own dedicated software AreaQuant™.
AreaQuanr™, the Acorn Area software, measures T1 using an inversion recovery pulse sequence, and measures T2 using the CPMG pulse sequencing method. The resulting data are analyzed to determine the relative proportion of bound and free liquid and the corresponding particle surface area.
There are no assumptions about the sample particle size (distribution) or shape used to determine surface area; the wetted area is measured directly. The user inputs the particle dispersion weight concentration, the liquid and particle density. The particle-to-liquid volume ratio (used in the calculation of surface area) is automatically determined.
There are two Operational Modes in the software setup: Standard (or QC) Mode and Advanced (or R&D) Mode. The former is the mode used to measure surface area. In R&D mode, the instrument behaves like a traditional NMR spectrometer capable of a wide range of low-resolution NMR measurements.
Measurements with the Acorn Area are simple and easy. Dispersions can be measured non-invasively, without dilution. The upper limit in concentration is essentially unlimited; the lower limit is about 1-2%.
Using this automatic mode, AreaQuant™ then determines all the measuring parameters needed such as the amplitude and duration of the pulses, the number of repetitions, etc. without operator intervention.This ensures measurements are made with the highest resolution and repeatability without a great deal of operator training.
To simplify method development, the software also features an automatic test parameter fle confguration based on an estimated T1 or T2 time input by the user.
Once a set of parameters are defned, operation of the Acorn Area is simple: just enter the operator name and sample information – the software does the rest.
AreaQuant™ operates on virtually all Windows Platforms, including XP®, Vista®, and Windows® 7. Data fles are saved in XML format, easily opened with Microsoft Excel or Open Offce. Reports are saved in RTF format. Graphs may be copied to the clipboard or saved in JPG or PNG formats. To make sure you are using the most up to date software available, updates may be downloaded and installed via the Internet with a single click of the mouse.
ACORN AREA Particle surface area
The wetted area of the active pharmaceutical ingredient (API) available to react with stomach acids controls the rate that the product will relieve acid indigestion. Two formulations may have the same weight percentage of API but may provide a different therapeutic beneft owing to a difference in the API surface area. This relates to the concept of bioequivalence of drugs, an important issue in the debate between brand and generic pharmaceutical companies.
Titanium dioxide is an important ingredient in many sunscreen products. UV radiation attenuation is directly related to the surface area of the TiO2 particles. Samples having the same particle equivalent spherical diameter may have dissimilar shape and morphology, resulting in vastly different levels of UV protection. Such differences are detectable via surface area measurement of the wet suspensions. Small variations in dispersion particle aggregation are easily detected in surface area measurements. Thus, the Acorn Area can be used to monitor the quality of the dispersion.
The rate at which a battery produces energy is related to the total amount of surface wetted by the reactants in the paste. Any surface not wetted will not contribute to energy generation. As energy storage becomes more and more important, the relationship between dispersion wetted surface area and product performance becomes critical.