Identification Of Rutile And Anatase Present In The Natural Cosmetic Foundations Using X-Ray Diffraction Phase Identification

Introduction

X-ray Diffraction is a technique used to study the physical properties, structure and chemical composition of the materials based on the pattern of the diffraction of the sample compounds. This technique has an important role in the study of the particles present in cosmetics as their properties attain the anticipated cosmetic features and also their uptake by the skin (XRD.co). In this study, the presence of amorphous and crystalline components present in the natural foundations is identified with the help of X-ray diffraction by phase identification. One such technique is going to be used in this study to identify the Rutile and Anatase present in the natural cosmetic foundations.

Experimental Detail

X-ray Diffraction provides important information about the components which show the semi-crystalline or crystalline properties. This is a less expensive technique, however, the role of expensive tools and instrumentation cannot be underestimated and must be restored to when precise details about the constituents of sample are required.

The faces of the crystal planes of the sample scatter the beams due to constructive interference and give the diffraction pattern. The sample is scanned by the X-ray incident beam over a range of degrees. This takes place by spinning the sample stage at a programmed angular scan rate.

Single crystal diffraction and powder diffraction are the two ways to carry out this technique. In the former, crystal is used, while in the latter, the amassed fine crystalline particles are used to get the diffraction pattern by the incident of the x-ray beam (Hideo).

X-ray Diffraction is a non-destructive technique that reveals the amorphous and crystalline proportion of the content. This technique is a significant tool for the identification of crystalline phases that are unknown. Various phases in the sample are identified and quantified. X-ray diffraction can identify the comparative amount of each phase, even when one of the phases is amorphous.

Steps

Natural foundations will be analyzed using X-ray Diffraction in order to identify the amorphous and crystalline components present in these foundations. Sample foundations will be analyzed using a Rigaku MiniFlex benchtop diffractometer. The X-ray diffraction pattern obtained from this sample is going to disclose the Rutile (amorphous) and Anatase (crystalline components) present in the foundations (rigaku.com). The crystalline component is identified by determining the intensities and position of diffraction peaks and by comparing it with the known library of crystalline materials.

Theories

There are many concepts and theories used in the X-ray Diffraction technique. One such concept is Bragg’s law, according to which the scattering is concerted at distinct points, and farther from these points, the mutual interference results in no remarkable scattering.

X-ray powder diffraction is a theory established by Debye & Scherrer and is an important technique for the characterization of the phases of materials, evaluation of microstructure, and determination of the molecular structure of materials and their quantitative proportion.

For each crystalline plane, scattering according to the Bragg condition is the base for the conventional theory of X-ray powder diffraction. According to this concept, there are enough crystallites in the right position to make the pattern observed. This made it practical in the beginning, using standard instrumentation, and there was the possibility of millions of illuminated crystallites at any one time. The orientation distribution of crystallite and the geometry of the instrument will give an idea of the intensities for the scattering peaks.

There are many remarkable differences in the estimated intensities when kinematical and dynamical theories are used, depending on the material. The conventional theory generally does not include the effects of refractive index for powders. However, according to the researchers, the dynamical theory includes them naturally (Fewstera).

References

Fewstera, Paul F. “A new theory for X-ray diffraction.” Acta Crystallogr A Found Adv 70 (2014): 257–282. <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4011009/#bb45>.

Hideo, Toraya. “Introduction to X-ray analysis using the diffraction method.” Rigaku Journal 32.2 (2016).

rigaku.com. “Phase identification of common minerals in natural facial cosmetics.” 2018. <https://www.rigaku.com/en/products/xrd/miniflex/app033>.

xrd.co. “http://xrd.co/applications-xrd-cosmetics/.” n.d. Applications of XRD-Cosmetics. <http://xrd.co/applications-xrd-cosmetics/>.