Depletion-enhanced optical trapping in nanoparticle suspensions

Joseph Junio; H. Daniel Ou-Yang

doi:10.1117/12.826386

20 August 2009 Depletion-enhanced optical trapping in nanoparticle suspensions

Joseph Junio, H. Daniel Ou-Yang

Proceedings Volume 7400, Optical Trapping and Optical Micromanipulation VI; 74001C (2009) https://doi.org/10.1117/12.826386
Event: SPIE NanoScience + Engineering, 2009, San Diego, California, United States

Abstract

With the right proportions, a binary suspension of different sized particles may be subject to entropic effects that can generate a depletion-induced attraction between large particles. A manifestation of the induced attraction is the enhanced osmotic compressibility of the larger species in the presence of the smaller species. We conducted an experimental study on how such an enhancement is affected for 190 nm polystyrene spheres in the presence of polyethelyne-oxide in aqueous solutions. Using the gradient force from a tightly focused laser, we can locally concentrate the polystyrene nanoparticles in suspension, and from the changes of local particle density under the known gradient force, we deduce a quantitative measure of the isothermal compressibility of the particles. We report the analysis of these compressibilities and their enhancement by the added polymers for a broad range of particle and polymer concentrations.

Citation Download Citation

Joseph Junio and H. Daniel Ou-Yang "Depletion-enhanced optical trapping in nanoparticle suspensions", Proc. SPIE 7400, Optical Trapping and Optical Micromanipulation VI, 74001C (20 August 2009); https://doi.org/10.1117/12.826386

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