Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Physicists gain new insights into nanosystems with spherical confinement

27.07.2017

Enormous potential for the targeted delivery of pharmaceutical agents and the creation of tailored nanoparticles

Theoretical physicists led by Professor Kurt Binder and Dr. Arash Nikoubashman at Johannes Gutenberg University Mainz (JGU) in Germany have used computer simulations to study the arrangement of stiff polymers in spherical cavities.


Bipolar structure assembled of stiff polymers at low densities.

Credit: Ill./©: Arash Nikoubashman, Mainz University


Quadripolar tennis ball structure of stiff polymers at high densities.

Credit: Ill./©: Arash Nikoubashman, Mainz University

These confined systems play an important role for a wide range of applications, such as the fabrication of nanoparticles for targeted drug delivery and for tailored nanomaterials.

Furthermore, the investigated systems can give crucial insights into the inner workings of biological problems where confinement effects are crucial, such as the packaging of double-stranded DNA in bacteriophage capsids and the self-assembly of actin filaments in cells.

The simulations have demonstrated that fully flexible chains are homogeneously distributed inside the spherical cavity, with an unstructured surface at the confining sphere. However, when the stiffness of the chains was increased, the polymers aligned in a parallel fashion with the chain ends ordered on a common equatorial plane.

At the same time, complex structures emerged on the sphere surface. At low densities and intermediate stiffness, the chains formed bipolar patterns (see Figure 1), as they are known from onions and globes. As the density and stiffness was increased further, the texture changed to a tennis ball-like structure with four distinct poles (see Figure 2).

These highly unusual states originate from the complex interplay between the packing and bending of the individual polymer chains. On the one hand, it is entropically favorable for stiff polymer chains to align parallel to each other. This so-called nematic phase is, for instance, crucial for the functionality of liquid crystal displays.

On the other hand, the spherical confinement impedes such an order throughout the whole system so that the chains close to the sphere surface have to bend, which is energetically unfavorable. The resulting structures are then the compromise out of these constraints.

These simulations provided the first opportunity to observe and study the self-assembly of stiff polymers in spherical cavities. The researchers around Dr. Arash Nikoubashman and Professor Kurt Binder are confident that their work will help to elucidate the behavior of both naturally occurring and synthetic soft systems in confinement.

Media Contact

Dr. Arash Nikoubashman
anikouba@uni-mainz.de
49-613-139-27254

 @uni_mainz_eng

http://www.uni-mainz.de 

Dr. Arash Nikoubashman | EurekAlert!
Further information:
http://www.uni-mainz.de/presse/aktuell/1988_ENG_HTML.php

More articles from Materials Sciences:

nachricht Novel sensors could enable smarter textiles
17.08.2018 | University of Delaware

nachricht Quantum material is promising 'ion conductor' for research, new technologies
17.08.2018 | Purdue University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>