Researchers develop process to make cotton both water repellent and UV resistant

Apr 11, 2011 by Bob Yirka report
Image credit: ACS

(PhysOrg.com) -- Researchers at Northeast Normal University in China, have come up with a three-step process that when applied to cotton material results in a fabric that is both waterproof and very highly UV resistant.

In a recent paper published in ACS Applied Materials & Interfaces, Lingling Wang and his associates describe a method of using zinc oxide nanorods and zinc oxide crystallites to create a coating that bonds to cotton fiber resulting in a material that its creators hope will help meet the needs of a world that wants multi-functional clothes; in this case, clothes that are "green" (don't need cleaning) and help protect the wearer’s skin from harmful ultraviolet radiation.

The process, using off the shelf , including the cotton material, was begun by soaking a piece of cotton cloth in ZnO nano-crystals for 12 hours, then putting it in a Teflon autoclave (high pressure steamer) that was saturated in a zinc acetate hydrate solution for 48 hours at 95° C. This first step resulted in the dissolution and then re-crystallization of the ZnO nano-crystals which gave it a ZnO seed layer. Afterwards, the material was allowed to dry for ten minutes.

The next step was to place the seeded back into the autoclave, this time in an aqueous solution of zinc nitrate hydrate and hexamethylenediamine (HMT) for 5 hours at 95° C. This step gives the material its water proofing abilities. Afterwards it’s rinsed and allowed to dry again.

The final step was to dip the material alternately in polyethylenimine (PEI) and silicate solutions creating a PEI/silica layer (shell).

The result is a material that is not only waterproof but is able to block out UV radiation from the sun to such an extent that it would rate a Ultraviolet Protection Factor (UPF) of 101.15 if the chart went that high. The rating is in effect, double the highest possible rating on the normal chart, and considerably higher than consumers are accustomed to seeing on suntan lotion bottles.

Though testing has not been done to see how the new process will hold up under real world conditions, the knowledge gained from the success of this procedure will no doubt advance the science of developing new clothes that will provide far more benefits to us all than simply covering our bodies.

Explore further: Carbon nanoballs can greatly contribute to sustainable energy supply

More information: Lingling Wang et al., Superhydrophobic and Ultraviolet-Blocking Cotton Textiles, ACS Appl. Mater. Interfaces, Article ASAP. DOI: 10.1021/am200083z
via Discovery

Related Stories

Chemists measure copper levels in zinc oxide nanowires

Feb 19, 2008

Chemists at the National Institute of Standards and Technology have been the first to measure significant amounts of copper incorporated into zinc oxide (ZnO) nanowires during fabrication. The issue is important ...

Recommended for you

Researchers use oxides to flip graphene conductivity

Jan 26, 2015

Graphene, a one-atom thick lattice of carbon atoms, is often touted as a revolutionary material that will take the place of silicon at the heart of electronics. The unmatched speed at which it can move electrons, ...

Researchers make magnetic graphene

Jan 26, 2015

Graphene, a one-atom thick sheet of carbon atoms arranged in a hexagonal lattice, has many desirable properties. Magnetism alas is not one of them. Magnetism can be induced in graphene by doping it with magnetic ...

The latest fashion: Graphene edges can be tailor-made

Jan 23, 2015

Theoretical physicists at Rice University are living on the edge as they study the astounding properties of graphene. In a new study, they figure out how researchers can fracture graphene nanoribbons to get ...

Nanotechnology changes behavior of materials

Jan 23, 2015

One of the reasons solar cells are not used more widely is cost—the materials used to make them most efficient are expensive. Engineers are exploring ways to print solar cells from inks, but the devices ...

Gold 'nano-drills'

Jan 22, 2015

Spherical gold particles are able to 'drill' a nano-diameter tunnel in ceramic material when heated. This is an easy and attractive way to equip chips with nanopores for DNA analysis, for example. Nanotechnologists ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.