Page 64 - May-June-2020

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PolyU, Electrostatically

charged PVDF

Nanofilters with multiple

separator layer

Nanofibers (100nm) possess extraordinary properties due to their high surface area and energy, have been
used in filtration media. The nanoaerosol (1 to 100 nm or below) includes airborne contaminants and viruses
that should not be inhaled because, air pollutant has adverse effect on health and environment.

Researchers under the supervision of Ir. Professor Wallace Leung Woon-Fong, Chairperson of Innovative
Products and Technologies, from Mechanical Engineering Dpt. at Polytechnic University Hong Kong, have
fabricated nanofiber filters with multiple separator layers. Nanoaerosol can be easily trapped by Polyvinylidine
fluoride (PVDF) nanofilters (PolyU) that are electrostatically charged by Corona discharge, an advanced
modification technique. PolyU nanofilters are more effective with 54% efficiency in grabbing the nanoaerosol
due to induced electrical interaction, compared to other charged microfiber or uncharged filters with efficiency
of about 17%. Similarly, efficiency of filter with multiple electrostatic separator layers is 39% -45% more than
filters without these layers.

“Maximum efficiency is attained when microbes are grabbed due to electrostatic force of attraction between
negatively charged virus or bacteria and positively charged PVDF nanofilters. Therefore, based on this
innovation the face mask would provide ideal protection” said by Professor Leung. The functionality of PolyU
nanfilters is due to induced charge that lasts for 3 months while in already existing microfilters the charge
dissipates within a day, making them potential candidate for industrial as well as personal use.

The ZDHC- Gateway of Hohenstein, providing waste water testing

In recent years, the concerns about ecological impact international accredited Hohenstein laboratories and
of wastewater, sustainability, and health and safety the program of ZDHC is supported to drive the
issues has become the main concerns of society industries on the path of least emission of harmful
leading the researchers to work intensively for the safer compounds.
environment. Various conventional and advanced
techniques have been adopted for the concept of As a member of ZDHC, Hohenstein laboratories are
“Zero Discharge of Hazardous Chemicals (ZDHC)”. working since December 2018, now, it has been
Hohenstein an internationally recognized research and internationally renowned waste water analyzing lab,
service center was developed in 1946 at Bönnigheim providing the services for testing the chemicals to be
(Germany). This institute is one of the originator of conformed for ZDHC Manufactured Restricted
OEKO-TEX® international association with foremost Substances List (ZDHC MRSL) by using an
concern of testing and textiles certification. independent testing certification system “ECO
PASSPORT” by OEKO-TEX®. Customers would also
Being a partner of textile industry Hohenstein research be provided with security and safety of
institute is ecstatic with main objective to reduce or ZDHC-compliant manufacturing, as result they would
even ban the hazardous chemicals that have been take the advantage to use non-hazardous chemicals
used for textile and leather products development. The during product development to escalate the
effluent of these industries have been inspected by conformance in resource functioning manner.

May/June 2020