Navigation Links
Nanoparticles assemble by millions to encase oil drops
Date:5/29/2008

HOUSTON -- May 29, 2008 -- In a development that could lead to new technologies for cleaning up oil spills and polluted groundwater, scientists at Rice University have shown how tiny, stick-shaped particles of metal and carbon can trap oil droplets in water by spontaneously assembling into bag-like sacs.

The tiny particles were found to assemble spontaneously by the tens of millions into spherical sacs as large as BB pellets around droplets of oil in water. In addition, the scientists found that ultraviolet light and magnetic fields could be used to flip the nanoparticles, causing the bags to instantly turn inside out and release their cargo -- a feature that could ultimately be handy for delivering drugs.

"The core of the nanotechnology revolution lies in designing inorganic nanoparticles that can self-assemble into larger structures like a 'smart dust' that performs different functions in the world for example, cleaning up pollution," said lead research Pulickel Ajayan, Rice's Benjamin M. and Mary Greenwood Anderson Professor in Mechanical Engineering and Materials Science. "Our approach brings the concept of self-assembling, functional nanomaterials one step closer to reality."

The research was published online today by the American Chemical Society's journal Nano Letters.

The multisegmented nanowires, akin to "nanoscale batons," were made by connecting two nanomaterials with different properties, much like an eraser is attached to the end of a wooden pencil. In the study, the researchers started with carbon nanotubes -- hollow tubes of pure carbon. Atop the nanotubes, they added short segments of gold. Ajayan said that by adding various other segments -- like sections of nickel or other materials -- the researchers can create truly multifunctional nanostructures.

The tendency of these nanobatons to assemble in water-oil mixtures derives from basic chemistry. The gold end of the wire is water-loving, or hydrophilic, while the carbon end is water-averse, or hydrophobic. The thin, water-tight sacs that surround all living cells are formed by interlocking arrangements of hydrophilic and hydrophobic chemicals, and the sac-like structures created in the study are very similar.

Ajayan, graduate student Fung Suong Ou and postdoctoral researcher Shaijumon Manikoth demonstrated that oil droplets suspended in water became encapsulated because of the structures' tendency to align their carbon ends facing the oil. By reversing the conditions -- suspending water droplets in oil the team was able to coax the gold ends to face inward and encase the water.

"For oil droplets suspended in water, the spheres give off a light yellow color because of the exposed gold ends," Ou said. "With water droplets, we observe a dark sphere due to the protruding black nanotubes."

The team is next preparing to test whether chemical modifications to the "nanobatons" could result in spheres that can both capture and break down oily chemicals. For example, they hope to attach catalysts to the water-hating ends of the nanowires that will cause compounds like trichloroethene, or TCE, to break into nontoxic constituents. Another option would be to attach drugs whose release can be controlled with an external stimulus.

"The idea is to go beyond just capturing the compound and initiate a process that will make it less toxic," Ajayan said. "We want to build upon the method of self assembly and start adding functionality so these particles can carry out tasks in the real world."

The research was supported by Rice University, Applied Materials Inc. and the New York State Foundation for Science, Technology and Innovation.


'/>"/>

Contact: Jade Boyd
jadeboyd@rice.edu
713-348-6778
Rice University
Source:Eurekalert

Related biology news :

1. Environmental fate of nanoparticles depends on properties of water carrying them
2. Researchers mimic bacteria to produce magnetic nanoparticles
3. MIT: Remote-control nanoparticles deliver drugs directly into tumors
4. Novel 3-D cell culture model shows selective tumor uptake of nanoparticles
5. Analysis of millions of US births shows association between birth defects and preterm birth
6. New Swedish research hope for millions of sufferers
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/11/2017)... Research and Markets has announced the addition of the ... ... grow at a CAGR of 30.37% during the period 2017-2021. ... prepared based on an in-depth market analysis with inputs from industry ... over the coming years. The report also includes a discussion of ...
(Date:4/11/2017)... NXT-ID, Inc. (NASDAQ:   NXTD ) ... appointment of independent Directors Mr. Robin D. Richards ... Directors, furthering the company,s corporate governance and expertise. ... Gino Pereira , Chief Executive ... their guidance and benefiting from their considerable expertise as we ...
(Date:4/5/2017)...  The Allen Institute for Cell Science today announces ... portal and dynamic digital window into the human cell. ... application of deep learning to create predictive models of ... a growing suite of powerful tools. The Allen Cell ... publicly available resources created and shared by the Allen ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... AMRI, a global contract ... to improve patient outcomes and quality of life, will now be offering its ... attributed to new regulatory requirements for all new drug products, including the finalization ...
(Date:10/11/2017)... , ... October 11, 2017 , ... ComplianceOnline’s Medical Device ... on 7th and 8th June 2018 in San Francisco, CA. The Summit brings together ... as several distinguished CEOs, board directors and government officials from around the world to ...
(Date:10/11/2017)... , ... October 11, 2017 , ... ... the implantation and pregnancy rates in frozen and fresh in vitro fertilization ... progesterone and maternal age to IVF success. , After comparing the results from ...
(Date:10/10/2017)... ... October 10, 2017 , ... Dr. Bob Harman, founder ... local San Diego Rotary Club. The event entitled “Stem Cells and ... had 300+ attendees. Dr. Harman, DVM, MPVM was joined by two human doctors: ...
Breaking Biology Technology: