What is swelling ratio?

The swelling ratio is defined as the fractional increase in the weight of the hydrogel due to water absorption. The sol fraction represents the fraction of the polymer following a crosslinking reaction that is not part of a crosslinked network.

Does PDMS swell in water?

PDMS does not swell in contact with water. The cost of fabrication in PDMS is low compared to that for many materials (e.g., glass or silicon) commonly used in microdevices and MEMs.

How do you find the ratio of swelling?

The swelling ratio (g/g) was measured by dividing the weight of the swollen gel by the weight of the initial dried sample.

How do you test for swelling?

Connect the system to a water reservoir with the level of water in the reservoir being at about the same level as the soil specimen and allow water to flow in the sample. Then allow the soil to swell. Record the free swell readings shown by the dial gauge under the seating load at different time intervals.

What can dissolve PDMS?

Try using n heptane. Based on my experience I have found n heptane to be one of the solvents that can dissolve pdms. You can use benzene, chloroform, toluene, and xylene.

Does PDMS absorb water?

In a PDMS-salt compound surrounded by water, the water which has entered the rubber is absorbed by the salt particles, creating an osmotic pressure in the rubber. The absorption and rupture phenomena were derived, measured, and quantitatively analysed.

What is swelling index?

Free swelling index is a measurement of increase in volume when coal is heated under specified conditions. A standard method (ASTM D720-91 (2010)) can be used to measure this characteristic.

How do you find the index of swelling?

The swelling index is defined as the volume in ml taken up by the swelling of 1 g of herbal material under specified conditions. Its determination is based on the addition of water or a swelling agent as specified in the test procedure for each individual herbal material (either whole, cut or pulverized).

What is the degree of swelling?

The degree of swelling can either be used directly as a relative measure of the average degree of crosslinking or as basis for calculating the average degree of polymerization of the molecule chains between two crosslink sites according to the theory of Flory and Rehner.

How do you swell PDMS?

Diisopropylamine swells PDMS to the greatest extent; solvents such as chloroform, ether, and THF swell the material to a large extent. Solvents such as acetone, 1-propanol, and pyridine swell the material to a small extent.

Does silicone absorb moisture?

Theoretical analysis and experimental studies have shown that moisture absorption characteristics of silicone rubber material are in good agreement with Fick’s law, and at a constant ambient humidity the diffusion coefficient and maximum moisture content of new silicone rubber are less than that of the operated.

How to measure the swelling of a PDMS?

To measure the extent of PDMS swelling, the volume swelling ratio (QV), defined as the ratio of the volume of swollen PDMS to its dry volume was calculated along with the weight swelling ratio (QW), defined as the ratio of the weight of swollen PDMS to its dry weight.

What is the weight of a PDMS sylgardr 184?

PDMS SylgardR 184 (Dow Corning Corporation) is a heat curable PDMS supplied as a two-part kit consist- ing of pre-polymer (base) and cross-linker (curing agent) components. The manufacturer recommends that the pre- polymer and cross-linker be mixed at a 10:1 weight ra- tio, respectively .

How are PDMS networks swollen by organic vapours?

In particular we will demonstrate that the swelling of PDMS by an organic vapour can be utilised as the actuating component in a wireless sensor. Passive radio frequency identification (RFID) sensors are highly desirable as they are low cost, energy-efficient, wireless and lightweight.

How does a child score on the pdms-2?

The child is asked to walk on a line, four inches wide and 8 feet long. If the child is able to walk on the line for six feet, a score of 2 is allocated. Scoring of the PDMS-2 is documented on the scoring profile or summary form. This is done after the administration of the test.