Praktikum Farmasi Fisik: Percobaan Mikromeritik - dibuat sebelum pandemi Covid-19

Summary

This video discusses various methods for determining particle size, distribution, and properties of powders. It covers techniques like using a microscope for measuring particle diameter, sieving for size distribution, and evaluating density through true, granule, and bulk densities. Additionally, it highlights the importance of measuring compressibility using tapped and bulk densities, and determining flow rate and angle of repose to understand powder behavior. These methods are crucial for accurately characterizing powders in industries like pharmaceuticals and materials science.

Takeaways

• 😀 The determination of particle size can be done using a microscope, sieving, or density methods.
• 😀 The three categories of particle sizes are fine particles, fine powder, and coarse powder.
• 😀 Optical microscopes are typically used for measuring particles between 0.2 micrometers and 100 micrometers.
• 😀 Calibrating the microscope involves aligning the ocular and objective scales before measuring particle diameter.
• 😀 A sample of zinc oxide is spread on a glass slide and measured under a microscope to determine its particle size.
• 😀 Sieving is a mechanical method where powders pass through a series of sieves with known hole sizes.
• 😀 The degree of fineness of a powder is indicated by a sieve number system, such as 22/60, which defines particle distribution.
• 😀 The sieving process involves using a mechanical vibrator to shake the sieves and separate particles based on size.
• 😀 Bulk density, tapped density, and true density are methods used to determine the density of powders, with each type considering different volumes and particle structures.
• 😀 Compressibility of powders is assessed by comparing the book density to the tapped density using a formula.
• 😀 Flow rate and angle of repose of granules or powders can be measured to assess their flowability in a powder tester.

Q & A

What are the different particle sizes mentioned in the script?

The particle sizes are divided into three categories: very small (fine), fine powder, and coarse powder.

What is the typical size range of particles measured using an optical microscope?

An optical microscope is typically used to measure particle sizes ranging from 0.2 micrometers to 100 micrometers.

What is the first step in measuring particle size using a microscope?

The first step is to calibrate the microscope by placing a micrometer under it, aligning the initial scale of the ocular scale with the initial scale of the objective scale.

How is a sample of zinc oxide prepared for particle size measurement?

A small sample of zinc oxide is placed on a glass slide and gently spread out using a spatula before measuring the particle diameter under the microscope.

What is the method used for particle size distribution determination in the script?

The script mentions the sieving method, where powder undergoes mechanical shaking to pass through a series of sieves with known hole diameters, from the largest to the smallest.

What does the term '22/60' mean in the sieving process?

'22/60' refers to the powder passing through sieve number 22 completely, with no more than 40% passing through sieve number 60.

What are the steps involved in determining particle size distribution using sieves?

The steps include cleaning the sieves, arranging them from largest to smallest mesh, adding 50 grams of granules to the top sieve, running the vibrator for 10 minutes, and weighing the granules collected in each sieve.

What are the three types of densities discussed in the script?

The three types of densities are True Density, Granular Density, and Bulk Density.

How is compressibility determined in the script?

Compressibility is determined by measuring the difference between Bulk Density (VB) and Tap Density (VT), using the formula: Compressibility (%) = [(VT - VB) / VT] * 100.

How is the flow rate and angle of repose determined in the script?

The flow rate is determined by timing how long it takes for 10 grams of powder to flow through a funnel. The angle of repose is calculated by measuring the height and diameter of the powder pile formed after the flow.