Category Limits Section
Applicability: Synapse (core versions 0315+)

Synapse generates new mixtures by first combining chemical components. For examples, if our design has two categories containing the following chemicals:

Solvent 1 Solvent 2
Ethanol Dimethyl sulfoxide
1-Propanol Water

Synapse would generate six candidate mixtures:

Ethanol + Dimethyl sulfoxide Ethanol + Water
1-Propanol + Dimethyl sulfoxide 1-Propanol + Water
2-Propanol + Dimethyl sulfoxide 2-Propanol + Water

Synapse then used the concentration limits specified in the Category Limits Section to generate a composition for each candidate mixture. These limits are used by both graphical and combinatorial mixture designs.

For example, if the entered category limits were:

Component Category Minimum Maximum Increment
Solvent 1 10.0 90.0 20.0
Solvent 2 10.0 90.0 q.s.

Synapse would generate the following compositions for the Ethanol + Water mixture candidate:

10.0% Ethanol + 90.0% Water 70.0% Ethanol + 30.0% Water
30.0% Ethanol + 70.0% Water 90.0% Ethanol + 10.0% Water
50.0% Ethanol + 50.0% Water

Synapse would then use techniques from the associated knowledge base to estimate the properties needed to evaluate the design constraints on each candidate.

Typical Usage

When creating a Mixture Design, either graphical or combinatorial, you:

  1. Specify the knowledge base to be used for the design. The knowledge base is specified in the design's Knowledge Base Section.
  2. Enter the ingredient categories in the Design Categories Section.
  3. Enter the chemicals for each ingredient category in the Category Chemicals Section0.
  4. Specify the concentration limits in this section. Note that since a concentration limits is specified for each Component Category, these must be entered first.
Example: Entering cateogry composition limits
  1. Open the MKS Mixture Design Examples document. This document is distributed with both Synapse's Professional Edition and Synapse's Basic Edition. See our library page for the latest version of this document.
  2. Create a copy of this document (see here) to use for this example.
  3. Change to the Combinatorials Chapter and natigate to the DMSO Cosolvents example design. (See the Navigation Overview documentation for details on navigating chapters and pages.)
  4. Scroll to the Category Concentration Limits Section.
  5. Click the left mouse button on the section's table control. Synapse activates the Category Limits dialog.
    Column listing each of the current component categories.
    Columns listing the current concentration limits for each component category.
    Total of all concentration minima. This value must be less than or equal to 100.
    Total of all concentration maxima. This value must be greater than or equal to 100.
    Pressing the edit button activates the Category limit dialog enabling you to enter minimum, maximum, and increment concentration values.
    See documentation on the Category Chemicals Dialog for additional details.
  6. Enter values for the minimum limit, the maximum limit, and the increment. Optionally, but recommended, enter values for the reference and comment.
  7. Finally, press the Category Limit dialog's OK button and the Category Limits dialog's Save button to store the limits in the current design.
Tip: Try large increments first

Depending upon the design's physical property constraints, you may want to initially try larger increments in your design. Such a design will typically give you a general understanding of how candidate composition affects the satisfaction of design constraints. You can then narrow the design limits and use a smaller increment to find a more specific solution.

You can always use Synapse's, or Cranium's, physical property estimation capabilities to investigate how your design's physical property constraints will change with composition. Estimating values for an example candidate's physical property or creating a General Calculation for more complication constraints, are two approaches for gaining more information on constraint behavior.

Related Documentation
Topic Description
Getting Started using Synapse provides a quick tour of Synapse's capabilities including examples of chemical product design.
Designing Chemical Products a short video demonstrating how to use Synapse to design candidate chemicals that satisfy a set of physical property and molecular structure constraints.