Aminated poly(vinylbenzylchloride-co-2,4,5-trichlorophenyl acrylate) microspheres for optical pH sensing

Necati Kaval; William Rudolf Seitz

doi:10.1117/12.372961

9 December 1999 Aminated poly(vinylbenzylchloride-co-2,4,5-trichlorophenyl acrylate) microspheres for optical pH sensing

Necati Kaval, William Rudolf Seitz

Author Affiliations +

Proceedings Volume 3860, Fiber Optic Sensor Technology and Applications; (1999) https://doi.org/10.1117/12.372961
Event: Photonics East '99, 1999, Boston, MA, United States

Abstract

Lightly crosslinked monodisperse poly(vinylbenzylchloride-co- 2,4,5-trichlorophenylacrylate) microspheres were prepared by dispersion polymerization. Then microspheres were derivatized with various secondary amines to convert the vinylbenzylchloride to a pH sensitive amine. These microspheres were embedded in poly(vinylyalcohol) hydrogel to form a membrane. Optical sensitivity of this membrane for pH is based on refractive index changes accompanying swelling and shrinking of the polymer microspheres. The membrane appears turbid (opaque-white) because the refractive index of microspheres is greater than that of the hydrogel. 2,4,5- trichlorophenyl acrylate (TCPA) was added into the polymer formulation in order to introduce porosity and hydrophilicity to the microspheres. In the amination procedure, the large 2,4,5-trichlorophenol group is replaced by the smaller amine forming a more hydrophilic amide. This shortened the response time of the membrane from hours to a few seconds. The membrane is more turbid at short wavelengths. In addition, turbidity of the membrane increases as the pH of solution increases. There is a linear relation between microsphere concentration of the membrane and its turbidity. The range in which the membrane is sensitive to pH is from 6 to 8.5, with an apparent pK_a of 7.5.

Citation Download Citation

Necati Kaval and William Rudolf Seitz "Aminated poly(vinylbenzylchloride-co-2,4,5-trichlorophenyl acrylate) microspheres for optical pH sensing", Proc. SPIE 3860, Fiber Optic Sensor Technology and Applications, (9 December 1999); https://doi.org/10.1117/12.372961

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available