Home / Knowledge / News / Textiles / Thin films of silk produce & combine with metallic particles
Thin films of silk produce & combine with metallic particles
25
Aug '09
Using thin films of silk as templates, researchers have incorporated inorganic nanoparticles that join with the silk to form strong and flexible composite structures that have unusual optical and mechanical properties. This bio-enabled, surface-mediated approach mimics the growth and assembly processes of natural materials, taking advantage of the ability of biomolecules to chemically reduce metal ions to produce nanoparticles—without harsh processing conditions.

Less than 100 nanometers thick, silk-silver nanoparticle composite films formed in this process can be used as flexible mirrors. The technique could also be used to create films that reflect light in specific wavelengths, anti-microbial coatings, thin film sensors, self-cleaning coatings, catalytic materials and potentially even flexible photovoltaic cells.

“We are taking advantage of biological molecules that have the ability to bind metallic ions of silver or gold from solution,” said Vladimir Tsukruk, a professor in the Georgia Tech School of Materials Science and Engineering. “These molecules can create mono-dispersed metallic nanoparticles of consistent sizes under ambient conditions—at room temperature and in a water-based environment without high vacuum or high temperatures.”

Sponsored by the Air Force Office of Scientific Research and the Air Force Research Laboratory, the research was described August 19 at the Fall 2009 National Meeting of the American Chemical Society.

The nanoparticles produced range in size from four to six nanometers in diameter, surrounded by a biological shell of between one and two nanometers. The silk template permits good control of the nanoparticle placement, creating a composite with equally dispersed particles that remain separate. The optical properties of the resulting film depend on the nanoparticle material and size.

“This system provides very precise control over nanoparticle sizes,” said Eugenia Kharlampieva, a postdoctoral researcher in Tsukruk's laboratory. “We produce well-defined materials without the problem of precipitation, aggregation or formation of large crystals. Since the silk fibroin is mono-dispersed, we can create uniform domains within the template.”

Atomic force microscope image shows a silk film on which gold nanoparticles were grown.

Fabrication of the nanocomposites begins by dissolving silk cocoons and making the resulting fibroin water soluble. The silk is then placed onto a silicon substrate using a spin-coating technique that produces multiple layers of thin film that is then patterned into a template using a nanolithography technique.

“Because silk is a protein, we can control the properties of the surface and design different kinds of surfaces,” explained Kharlampieva. “This surface-mediated approach is flexible at producing different shapes. We can apply the method to coat any surface we want, including objects of complex shapes.”

Next, the silk template is placed in a solution containing ions of gold, silver, or other metal. Over a period of time ranging from hours to days, nanoparticles form within the template. The relatively long growth process, which operates at room temperature and neutral pH in a water-based environment, allows precise control of the particle size and spacing, Tsukruk notes.


Must ReadView All

Courtesy: Asmara Group

Apparel/Garments | On 20th Sep 2018

Fragmented nature of Indian apparel sector major challenge

A major challenge for the Indian apparel sector is its fragmented...

Courtesy: Aditya Birla Retail

Apparel/Garments | On 20th Sep 2018

Indian Aditya Birla Retail to be acquired by Samara-Amazon

India’s Aditya Birla Group has signed a deal to sell Aditya Birla...

India's 2018-19 forward cotton export contract up by 100%

Textiles | On 20th Sep 2018

India's 2018-19 forward cotton export contract up by 100%

Rise in demand from China, lower domestic prices and depreciation of...

Interviews View All

Milind Khandwe, Hindoostan Innovation Centre

Milind Khandwe
Hindoostan Innovation Centre

‘Modern technical textile is an indispensable tool for science and...

Sunil Kumar Sharma, Loknayak JPNSSSG Ltd

Sunil Kumar Sharma
Loknayak JPNSSSG Ltd

'The blend of cotton–linen yarn has high demand in the domestic and...

Top executives, Textile industry

Top executives
Textile industry

Defining MSMEs on the basis of turnover makes it simpler to do business

Liz Manning,

Liz Manning

<div><b>Liz Manning</b>, Business Development Manager at Catexel, has...

Harsh Shah,

Harsh Shah

Fynd is the central online shopping destination for fashion, offering...

Mark Tokuhara,

Mark Tokuhara

Japan-based FitJoy, a shoe brand for women, has been in the footwear...

Robin Grankvist, OrganoClick AB

Robin Grankvist
OrganoClick AB

Robin Grankvist talks about PFCs, additives and various chemicals used in...

Urs Stalder, Sanitized AG

Urs Stalder
Sanitized AG

Urs Stalder, CEO, Sanitized AG, talks about the increasing use of hygiene...

Razvan Popescu, Directa Plus SpA

Razvan Popescu
Directa Plus SpA

Directa Plus is one of the largest producers and suppliers worldwide of...

Robert Brunner, Devereux

Robert Brunner
Devereux

Golfwear and menswear brand Devereux is set for greener pastures. Robert...

Tony Ward, Tony Ward

Tony Ward
Tony Ward

"You have to truly understand what your client wants, know her needs, what ...

Judy Frater, Somaiya Kala Vidya

Judy Frater
Somaiya Kala Vidya

Among the many honours showered on Frater, including Fulbright and Ford...

Press Release

Press Release

Letter to Editor

Letter to Editor

RSS Feed

RSS Feed

Submit your press release on


editorial@fibre2fashion.com

Letter To Editor






(Max. 8000 char.)

Search Companies





SEARCH

Leave your Comments


September 2018

Subscribe today and get the latest update on Textiles, Fashion, Apparel and so on.

news category


Related Categories:

Advanced Search