Improving Pigments & Dyes

Coloristic properties of pigment and dyes in paints and coatings are not solely determined by their molecular or crystalline structure, but depend heavily on their interaction with their surrounding environment. For example, dispersion stability in paint or dye formulations is crucial for the final stability and optical properties of the coating.

Materials Studio modeling and simulation software modules, such as Amorphous Cell and Forcite, can help you study the interaction of polymer matrices and pigments or dyes, as well as their mobility and interfacial strength. The Materials Studio Morphology module can be used to derive relevant surface structures of pigments to enable these studies. Organizations who are either resource-restricted or feel that they have no computational chemistry expertise can choose Accelrys’ Contract Research Services to help find solution for their business-critical scientific needs

Pigment Additive Design to Improve Stability and Coloristic Properties

Pigments are often coated to improve the dispersion and adhesion properties within the formulation. Choosing the best coating agent can be a daunting task because the design space is typically large. Materials Studio Morphology can be used to determine the predominant surface structures, which can give a guideline for designing additives that both bond strongly to the pigment surface and improve the surface chemistry in terms of favorable interactions with the surrounding polymer matrix.

Related Software and Services:

• Materials Studio Morphology - prediction of crystal morphology from the atomic structure of a crystal
• Contract Research & Scientific Consulting Services - organizations who are either resource-restricted or feel that they have no computational chemistry expertise choose Accelrys’ Contract Research Services to help find solution for their business-critical scientific needs

Related Case Study:

Controlling Crystal Morphology or Additive Design in Paint Formation

Color

Predicting the color of a molecule involves calculating the absorption spectrum. However, the color of the molecule will be influenced by its environment and hence this should be accounted for. Also, most pigments are crystalline in nature and their crystal morphology will affect the strength of color and color saturation. Accelrys solutions can be be used to provide initial structures (Forcite Plus), predict the UV spectra (VAMP), and predict the crystal morphology (Morphology).

Related Software and Services:

• Materials Studio Forcite Plus - classical simulation, molecular dynamics and analysis tools
• Materials Studio VAMP - semi-empirical molecular orbital package for molecular organic and inorganic systems
• Materials Studio Morphology - prediction of crystal morphology from the atomic structure of a crystal
• Contract Research & Scientific Consulting Services - organizations who are either resource-restricted or feel that they have no computational chemistry expertise choose Accelrys’ Contract Research Services to help find solution for their business-critical scientific needs

Related Case Study:

Optical Absorption Spectra of Melanins - a Comparison of Theoretical and Experimental Results

Transport and Diffusion

Transport of the dye through channels in the hair can be simulated directly using atomistic modeling such as Forcite Plus. Compatibility between the dye and the host  is important to improve the binding properties of the dye and host. Materials Studio modules such as Forcite Plus and Amorphous Cell can be used to predict the compatibility between host and dye.

Related Software and Services: Related Software and Services:

• Materials Studio Forcite Plus - classical simulation, molecular dynamics and analysis tools
• Materials Studio Amorphous Cell - comprehensive set of model construction, simulation, and analysis tools for predicting properties of amorphous systems
• Contract Research & Scientific Consulting Services - organizations who are either resource-restricted or feel that they have no computational chemistry expertise choose Accelrys’ Contract Research Services to help find solution for their business-critical scientific needs

Related Case Study:

Molecular Modeling Studies of Polymeric Transdermal Adhesives: Structure and Transport Mechanisms

Reactions

In certain situations, dyes are delivered in smaller fragment molecules that are reacted to form the dye in-situ as the complete dye molecule is too insoluble and big to diffuse in an appropriate time scale. Accelrys solutions can help. Materials Studio DMol³ is a quantum mechanics tool that can be used to examine the reactivity of the fragment molecules at their reactive site.

Related Software and Services:

• Materials Studio DMol³ - density functional theory (DFT) quantum mechanical code to simulate chemical processes and predict properties
• Contract Research & Scientific Consulting Services - organizations who are either resource-restricted or feel that they have no computational chemistry expertise choose Accelrys’ Contract Research Services to help find solution for their business-critical scientific needs.

Bibliography: Improving Pigments & Dyes

1. Jacobson, S. H., "Molecular Modeling Studies of Polymeric Transdermal Adhesives: Structure and Transport Mechanisms", Pharmaceutical Technology, 1999, September, 122-130
2. Stark, K. B.; Gallas, J. M.; Zajac, G.W.; Eisner, M.; Golab, J. T.,J. Phys. Chem. B, 2003, 107, 3061.
3. Barto, R. R.; Frank, C.W.; Bedworth, P. V.; Ermer, S.; Taylor, R. E.Proc.J. Phys.Chem. B, 2004,108, 8702.
4. P. Erk, J. Hetzenegger, A. Böhm, European Coating Journal, 1997, 906.