STRONG ANTIBACTERIAL - Hauzer Techno Coating · infections. Coatings with antibacterial effect...
Transcript of STRONG ANTIBACTERIAL - Hauzer Techno Coating · infections. Coatings with antibacterial effect...
Anywhere crowds of people gather, touch-based contamination contributes to the spread of bacterial
infections. Coatings with antibacterial effect could have an important public health benefit: think of door
handles, bathroom taps and other high-touch elements in schools, hospitals, airports and even homes. “The
new test results for Hauzer’s antibacterial coatings are excellent,” says Huub Vercoulen, Deco Sales Manager.
“Some eliminated all applied bacteria even after a single hour. We are now looking for customers
interested in jointly developing an antibacterial coating for their specific application.”
STRONG ANTIBACTERIAL EFFECT IN ENHANCED
COATINGS
Antibacterial in Rose Gold, Nickel and Black
Silver (Ag) and copper (Cu) ions have long been known
to have an antibacterial effect. Hauzer R&D developed a
coating architecture able to release these ions. The first three
enhanced coatings are rose gold, nickel-like and black. These
coatings are deposited either by Hauzer Advanced Controlled
Arc evaporation (ACA) or unbalanced magnetron sputtering
(UBM) and contain Ag or Cu in different concentrations.
Gram+ and Gram- Bacteria
Bacteria can be classified into Gram positive and Gram
negative, based on important differences in their cell walls.
Huub: “We previously tested whether Gram- bacteria
Escherichia coli could survive for 24 hours on enhanced
Hauzer coatings. Now, our testing partners Manchester
Metropolitan University (MMU) assessed the antibacterial
effect after 1, 3, 8 and 24 hours. They also tested
Staphylococcus aureus, which are Gram+ and can exist in
antibiotic-resistant form known as MRSA. Together, these
bacteria are a good model for unwashed hands, since they
live on skin and in faecal matter.”
MARKET DEVELOPMENT
The testing methodology is based on BS ISO 22196:2011 (Measurement
of antibacterial activity on plastics and other non-porous surfaces).
MMU researchers inoculated E. coli or S. aureus bacteria onto the
coating and sandwiched it with a piece of polyethylene to ensure the
cells are evenly spread across the surface. After 0, 1, 3, 8 and 24 hours
of incubation, any E. coli or S. aureus that were still alive were recovered
from the surface and spread onto agar to grow into bacterial colonies,
allowing for the calculation of colony-forming units per ml (CFU/ml).
MMU METHODOLOGY TO TEST ANTIBACTERIAL EFFICACY
cfu
/mL
102
101
104
103
105
107
106
E. coli test results
Black (
UBM) +
Ag
Black (
UBM) +
Cu
Nickel (A
CA) - unm
odified
Nickel (A
CA) + A
g 1Nick
el (ACA) +
Ag 2
Uncoat
ed stain
less st
eel
**** **** ** * *
Rose go
ld (ACA) +
Ag
0 1 3 8 24
Time points (hours)cf
u/m
L
102
101
104
103
105
107
106
S. aureus test results
Black (
UBM) +
Ag
Black (
UBM) +
Cu
Rose go
ld (ACA) +
Ag
Nickel (A
CA) - unm
odified
Nickel (A
CA) + A
g 1Nick
el (ACA) +
Ag 2
Uncoat
ed stain
less st
eel
**** **** *
0 1 3 8 24
*
Time points (hours)
Excellent Antibacterial Properties
Compared to an uncoated stainless-steel sample or an
unmodified nickel coating, all enhanced coatings showed
an antibacterial effect. Ivan Kolev, Hauzer Process Manager:
“Both black coatings were extremely effective: 100% kill rate
in only an hour. The rose gold coating eradicated E. coli within
4 to 8 hours and S. aureus within 9 to 24 hours. The Ni-like
coatings showed least efficacy, although still better than the
uncoated or unmodified samples. Nickel coating 1 achieved
full eradication of both bacteria within 9 to 24 hours, whilst
nickel coating 2 managed to decrease the population of
S. aureus by 3 orders of magnitude after 24 hours.” The
performance difference between the two enhanced nickel
coatings is a result of the different level of doping. This
indicates that there is an optimum dopant level.
Depending on the coating type and dopant added, there
can be a marginal colour shift as measured with the L*a*b
colour scale. This can be compensated by readjusting process
parameters.
Seeking Development Partners
With these excellent test results, it is now time to start developing
applications for these antibacterial coatings. Please contact
Huub Vercoulen ([email protected] or +31 6 462 01 462) to
discuss your specifications. Huub: “Are you interested in offering
an antibacterial effect as a selling point for decorative coatings?
Producing door handles or bathroom fixtures that help control
infection? Or coatings for antibacterial jewellery, keyboards
or other innovative products? This market is only just getting
started.”