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Microencapsulation Study from DSX1000

Fragrances or essence play an important in rejuvenating the mind and the body. Usage of fragrance has been there for many years but retaining of fragrance was a challenge and due to microencapsulation, it is now possible.

The Microencapsulation, also known as micro-shell, is a complex technique that involves the creation of polymeric shells, whether natural or synthetic, in which particles of active ingredients and scents are stored inside and thus remain and kept protected from the environment

How does it work?

Active core which is enclosed in the capsule releases instantly on the fabric or textile material, when a mechanical movement such as abrasion, deformation, and friction occurs, and ultimately the active agents are released on the skin

Techniques to Manufacture Microcapsules 

·        Pan coating

·        Centrifugal extrusion

·        Inotropic gelation

·        Coacervation-phase separation

·        In situ polymerization

·        Emulsion cross-linking

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Olympus DSX1000 microscope a Contact angle goniometer.

Olympus DSX1000 Microscope a Contact Angle Goniometer.

The contact angle is the angle, conventionally measured through the liquid, where a liquid–vapor interface meets a solid surface. A given system of solid, liquid, and vapor at a given temperature and pressure has a unique equilibrium contact angle. The equilibrium contact angle reflects the relative strength of the liquid, solid, and vapour molecular interaction.

Industries that benefit from contact angle measurement

Nanotechnology

Semiconductors

Textile & Fiber

Polymers and Plastics

Insecticides

Oil and Petroleum

Hard Disk Drives

Polymers and Plastics

Young’s equation is used to describe the interplay of the forces of cohesion and adhesion and to calculate surface energy.

A drop with a contact angle greater than 90 degrees is hydrophobic. This situation is characterised by poor wetting, weak adhesiveness, and a low solid surface free energy. A hydrophilic drop has a modest contact angle. This state indicates improved wetting, adhesiveness, and surface energy.

Types of Contact Angle Measurements

Static Contact Angle

This is perhaps the most popular measurement method. A single reading on a static sessile drop soon after it was created. When the three phases of solid, liquid, and gas establish thermodynamic equilibrium, a static contact angle is captured.

The static contact angle gives useful information about the surface’s qualities. The static contact angle can be measured using any ramé-hart equipment.

Contact angle is frequently used to assess cleanliness. Organic pollutants inhibit wetting and increase contact angles on hydrophilic surfaces. Contact angle normally decreases as wetting improves and surface energy increases as a surface is cleansed and treated to eliminate impurities.

Contact angle is frequently used to assess cleanliness. Organic pollutants inhibit wetting and increase contact angles on hydrophilic surfaces. Contact angle normally decreases as wetting improves and surface energy increases as a surface is cleansed and treated to eliminate impurities.

The static contact angle can also be affected by surface roughness. See our September 2010 Newsletter for further information about roughness.

A dynamic contact angle measurement is any contact angle measured on a moving drop. This includes, but is not limited to, tilting plate contact angle measurements, volume addition and subtraction, and time-dependent research.

Time-dependant Dynamic Studies

Researchers frequently monitor the contact angle over time to investigate the effects of absorption, evaporation, and more unusual phenomena such as the Cassie to Wenzel transitional states. Other time-dependent research examine how contact angle changes over time as environmental conditions (such as temperature and humidity) change. In some circumstances, the drop is altered by the addition of a chemical that increases or decreases surface tension.

Many scholars have been studying the Cassie and Wenzel states in recent years in order to better comprehend superhydrophobicity. In a Cassie state, a drop lies on top of asperities, with air gaps beneath it, as depicted in the image below.

Tilting Plate Method

The tilting plate method captures the contact angles measurements on both the left and right sides of a sessile drop while the solid surface is being inclined typically from 0° to 90°. As the surface is inclined, gravity causes the contact angle on the downhill side to increase.

OLYMPUS DSX1000 DIGITAL MICROSCOPE EXPLORES CONTACT ANGLE

Investigate the contact angle of a wooden surface with coatings.

The contact angle of water on various coatings was measured using an Olympus DSX1000 microscope tilt frame with a 3x objective.

DSx1000 powerful software allow easy measurement of contact angle and surface roughness. Here we are focusing on contact angle.

Measurement of contact as follows.

We can deduce from the above results that the contact angle values change depending on the coating, which reflects the relative strength of the liquid, solid, and vapour molecular interactions.

 

We also investigated the contact angle on raw mango wood and the contact angle after coating.

Surface Roughness

Olympus DsX1000 microscope is also capable of measuring surface roughness of wood before and after coating.

Ra and Sa parameters are evaluate from 3d image captured by the microscope.

Please feel free to connect with us to know more and  share us your samples

We would extend our thanks to “Mr. Saurabh Kothari” from “Sansui Paints” for his contribution.

Author- Gyanesh Singh Application Specialist at IR Technology Services Pvt. Ltd Passionate about Microscopy for Micro and Nanostructures. Gyanesh has over 10 years of experience in demonstration and serving application of various techniques to potential clients and enjoys learning new sophisticated scientific technology for Material Science and Life Science.

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Multidimensional gas chromatography (MDGC)

Multidimensional gas chromatography (MDGC) is now an established technique for the analysis of complex samples in application areas such as petrochemistry, metabolomics, environmental, and flavor and fragrance science.

The technique uses GC columns connected in series to achieve a complete separation of complex samples using orthogonal column chemistries. These separations are either impossible or very time consuming using a one-dimensional (1D) technique (that is, using only one GC column).

In a situation where the first dimension has a peak capacity of 1000 and the second dimension has 30, the 2D GC×GC system would offer a peak capacity of 1000 × 30 = 30,000. To achieve such peak capacity with a 1D separation, a 2-km GC column would be required (analysis time on the order of 1.5 years)!

Second-dimension columns must achieve separation much faster than their first-dimension counterparts to optimize the “sampling rate” from the first dimension and, therefore, they tend to be short. The length of the first column might typically be 20–30 m, the inner diameter 0.25 mm, and the film thickness 0.25 μm. The second column is typically shorter (1–2 m), the inner diameter is narrower (0.1 mm), and the stationary phase is thinner (0.1 μm), to allow for faster separations. The reduction in internal diameter is used to counterbalance the decreases in efficiency (plate numbers) obtained from shorter columns. It is common to select a nonpolar column for the first-dimension separation and use a more highly polar phase in the second dimension.

The major instrument challenge in multidimensional GC is to achieve efficient “injection” of the effluent of the first dimension into the second. Columns joined in series are the simplest embodiments of multidimensional chromatography; however, the separations produced are limited by carrier-gas velocities because all the solutes transit both columns in a single continuous stream. When working with complex samples, peaks that are well separated by elution from the first column can come back together or might interfere with other peaks as they pass through the second column. Therefore, we need to “trap” or “bunch” discrete fractions from the first column before introduction into the second dimension. This is typically achieved using a “modulator” that is used to transfer effluent from the first-dimension column to the head of the second-dimension column in short repetitive pulses. Modern instruments use two types of modulators: thermal (cryogenic or heated) and valve (time or pressure) modulators. Regardless of the design or principle, the rapid and efficient transfer of discrete fractions from one, many, or all peaks in the first dimension is absolutely critical to maintain the separation quality. There are as many subtle variations in the design and implementation of modulator devices as there are instrument manufacturers; however, there is no doubt that the modulator is the heart of the GC×GC system.

In “heart-cutting” systems, one or several discrete portions of a separation are directed from the first column to the second. Because only a few selected peaks enter the second column at a time, interference from other nearby peaks that precede or follow the heart cut is eliminated, and the second column’s separation becomes largely independent from the first one.

In the much more complex technique of comprehensive multidimensional GC, all of the effluent from the first dimension column is sampled into the second. Correct sample modulation is essential in the comprehensive technique to successfully maintain resolution of all components in both the first and second dimensions. This technique generates huge amounts of data, and complex software is required to reduce the data to a usable form, typically represented via a 2D or 3D plot of the type shown in Figure 1. This 2D contour plot of a separation of light cycle oil uses colors to represent the signal intensity; the x-axis plots the separation in the first dimension (in minutes), and the second-dimension separation is plotted on the y-axis (in seconds).

Multidimensional GC data are primarily used for qualitative analysis. However, quantitative multidimensional analysis is possible.

While multidimensional GC brings many separation benefits, achieving efficient analyte transfer between columns and the complexity of data analysis are potential barriers to more wholesale adoption as a routine analytical technique.

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