world leaders in repellent surfaces - pci mag...pccp 15 581-585 2013 nano lett. 13(4) 1793-1799 2013...

September 12th 2019

Coatings Trends & Technologies

Teluka Galhenage, Chetan Khatri, Alex Vena, Andrew Labak,

Terry Banks, Grant Tremelling, and Philseok Kim

Novel modular additive approach for designing

biocide-free coatings to control biofouling

World Leaders in Repellent Surfaces

© 2019 Adaptive Surface Technologies

‘Sticky Problems’ are Ubiquitous

Sticky

Sticky

Sticky


And Sticky Problems Do Matter!

Efficiency

Safety

Economic

Problems

$10B/yr more

fuels burned

More CO2 emission

3.5% of domestic

energy use goes to

waste water treatment

11% of total energy used

for defrost

Poor quality of foods

Wasted time, labor, cost

for cleaning after each batch

More chemicals, more wastes

~2M/yr HAIs, >$30B/yr

spent in the US

40% of HAI = CAUTI

7-18% of consumer

products turns

into waste


Tree 2(12) 364 – 369 (1987), PNAS 101 14138 – 14143 (2004),

Proc. R. Soc. B (2008), Plant Signaling & Behavior (2009), Prog. Nat. Sci. (2009)

A Clever Way to Deal With Preys ‘Sticking’

Lessons learned from Nature:

• Use Liquid Surface

• Keep the liquid by ‘chemistry’

• Keep the liquid by ‘physics'


We turned the lessons from Nature into a new materials design concept that we call SLIPS!

Slippery Liquid-Infused Porous Surfaces

infuse with

a lubricant

liquid/solid

being repelled

surface functionalization/

conditioningsurface

roughening

100% fully slippery liquid interface

lubricating film in and over a solid surface

• Sub-nanometer smoothness

• Excellent repellency to almost everything

• High pressure/temperature tolerance

• Self-healing characteristics

• Highly customizable system

Nature 477 443-447 2011

ACS Nano 6(8) 6569-6577 2012

PNAS 109(33) 13182-13187 2012

PCCP 15 581-585 2013

Nano Lett. 13(4) 1793-1799 2013

Nature Materials 12 529-534 2013

Appl. Phys. Lett. 102 231603 2013

Nature Commun. 4 2013

Nanotechnology 25 2013

Angew. Chem. Int. Ed. 53 2014

First patent filed on 01/19/2011, issued on 09/01/2015

First public disclosure on 06/15/2011 at TechConnect World (Harvard-MIT Tech Innovation Presentation)

“Robust Slippery Surfaces as Optically Transparent, Oleophobic, and Anti-icing Materials”


Yet Another Approach to Create Slippery Surface

Substrate

Surface Treatments

Surface SLIPS(sSLIPS)

✔SLIPS surfaces feature

an immobilized liquid

lubricant overlayer—

completely smooth and

fully slippery

Solid surfaces

are rough and have

many pinning points

Reservoir SLIPS(rSLIPS)

Paints / Curable Mixtures

Substrate


Commercial Uses For Highly Repellent Surfaces

BIOFOULING-FREE SHIPBIOCIDE-FREE, ECO-FRIENDLY

VISCOUS LIQUID MANFUACTURINGEASY-CLEAN, HIGH-EFFICIENCY

Less Fouling

Less Contamination

Less Cleaning

Less Energy Use

Less Environmental Impact

Less Batch Cross-Contamination

Less Waste

Less Energy & Water use

Less Production Downtime


SUSTAINABLE PACKAGINGEASY-EMPTYING, RECYCLABLE

Less Design Restriction

Less Cleaning

Less Contamination

Less Waste



sSLIPS applied on a SS hopper (diameter = 1’)


Market Segmentation: Biofouling in Marine Environment

~60% of total

marine coating

market

Total annual fuel use: 370 M tonnes ($90B in fuel costs)

Energy use: ~13 Quads (2% of world energy)

CO2 emissions: 1.1 B tonnes

Worldwide Deep sea commercial fleet ~100,000 vessels worldwide

$3.5 Billion

850 Kilo Tons

CAGR – 6.1%

$100M sale of

pleasure craft

underwater coatings

in the US

US Recreational boat marketNo. 1 in pleasure boats ownership in the world

No. 1 in consumption of AF paints

Key suppliers:

Interlux (AkzoNobel)

Pettit Paint (RPM)

Sea Hawk Paints

Private Label paints

No pleasure craft company has been able to create

an effective Biocide Free Foul Release bottom paint

$1.4b aquaculture market in the US

50% direct labor cost for cleaning nets

High demand due to $14b deficit in

seafood annually in the US

15 million aquariums in US

At $10-15 per aquarium

~$200M total market for SLIPS

Niche market

The ultimate solution and “category killer” will be 100% biocide free,

while delivering high anti-fouling performance over long durations


Silicone-based rSLIPS

Substrate

Lubricant Silicone

Controlled

Regeneration

Non-toxic coating chemistry

x

No toxicity

C. reinhardtii (single cell green alga)

‘Baier curve’

J. Mater. Sci: Mater. Med., 18, 1057-1062 (2006)


Silicone-based rSLIPS Shows Some Promise but Not Enough

Long-term Field Performance

2.5 years in Singapore

premium

FR

(pFR)

StaticRegular

Cleaning

(-) Control

(Singapore, July ‘15 – Dec. ‘17)

SLIPS

(Gen. 0)

How can we improve the

performance further?

Gen. 0, 2012-2014Repellency to Soft & Hard Fouling

Releases

soft fouling

Repels

hard fouling

ACS Biomat Sci. Eng.. 1 43-51 2015

Nature Commun. 6 8649 2015

ACS AMI 6 13299-13307 2014

Science 357 668-673 2017


Controlling Biofouling Requires Additional Strategies

Adopted and modified from Frank T Moerman

J. Hygienic Engr. Design, 7, 8-29 (2014)

Physical

Module

Chemical

Module

Amphiphilic chemistry

HLB/solubility

Modular additives

Chemistry of lubricant

Hybrid

Module

Releasing or Bound biocide

Reinforced matrix

Surface texture

Natural antimicrobial compounds

Liquid interface

Slippery surface

Self-lubricating

Self-healing

Surface modulus

AST’s current development focus

Can this be a

non-fouling zone?


Non-Fouling Chemical Moieties

• Natural anti-fouling surfaces generally exhibit both physical and chemical attributes

• Hydrophilic, charge-neutral, hydrogen bonding acceptors are generally known to have very low protein adsorption

• polyethyleneglycol (PEG) – often behaves like hydrogel

• zwitterionic moieties – many of them are found in naturally existing compounds

• water molecules are strongly adhered and form so-called ‘hydration layer’ which requires ‘additional work’ for the fouling organisms to displace in order to attach themselves

• entropic changes associated with conformational changes of these groups with and without water molecules


Physical and Chemical Modules in One System

Additional Layer of Chemical Protection Physical Module + Chemical Module

Lubricant Silicone

Matrix

Bound

Amphiphile

Substrate

Gen. 1 “N1“ (2017)


Laboratory Biological Assay Tests

Navicula incerta

(diatoms)

Ulva linza

(green algae)

Algae

Cellulophaga lytica

Bacteria

Barnacles

Amphibalanus amphitrite

Mussels

Guekensia demissa


Enhanced Non-Fouling Properties Observed From Gen. 1

Month 1 Month 2 Month 3 Month 4 Month 5 Month 6 Month 7

SLIPS

(Gen. 1)

Copper-

SPC

(Navy

standard)

PVC

(control)

Static panels

Pt. Canaveral, FL


2018 Boat Paint Testing with Gen. 1 (aka. ‘N1’)


Amphiphilic Lubricant Further Improves Performance

Excellent Dynamic ReleaseImproved Static Performance

Lead pFR Lead AF

8-9 knots, Norway (Jul. ’18 – Nov.’18)

Singapore (Jul. ’18 – Dec.’18)

Gen. 1+ Lead pFR Lead AFGen. 1

Gen. 1+ (aka. ‘N1x’) (Q4 2017)

Gen. 1+Gen. 1


Design & Synthesis of Active Building Blocks/Formulation

silicone backbone

amphiphilic group

spacer

multi-functional brush-like molecular architecture (SAP)

reactive group ***

a b c d e

• initially homogenized system evolves to a

phase separated, structured system

• solubility-driven structuring

• interfacial energy-driven structuring

• evaporative structuring

• curing continues but the speed depends

on humidity

• dynamic contact angle behavior observed

condensation cure

silicone binder system

pigments

/filler

crosslinker

/catalyst

/solvent

lubricantSAP

Active Performance Ingredient (API)

• highly tunable structures (>50 compound library)

• enables modular approach

• structures confirmed by NMR and FT-IR

• up to 1 kg scale (in-house)

• toll manufacturable chemistry

• patent pending on the compounds, compositions,

and articles

(patent pending)


Surface Structure Upon Curing

5:20

10:60

1:40

10:40

15:40

5:40 5:60

50 µm

Optical microscopy

domain size?

% coverage?

their effect on biofouling?

(% loading):(% PEG in SAP)

% amphiphilic component in SAP

% concentration of SAP in the formulation

% loading of lubricant in the formulation


Discontinuous Phase is Concentrated with Hydrophilic Material

PEG (1470 cm-1)

High at circle

center

PEG (1285 cm-1)

High at circle center

Silicone* (1410 cm-1)

High at circle edges

+

+

+ +In

ten

sity

Line Scan of Circular Feature

~7 µm diameter

Confocal Raman


Domain Size and Surface Coverage are Tunable

*due to heterogeneity of the system, exact values may slightly vary but the data here represents the trends

SAP with 40% PEG with varying % loading10% SAP with varying % PEG


The Coated Surface is Not Flat at Microscale

in Air

in Water

(1 month)

Rq : 75 ± 7 nm 148 ± 9 nm

Binder only

No significant roughness change

10% SAP


0 50 100 150

60

70

80

90

100

110

120

Unmodified silicone

100100

100101

Wa

ter

con

tact

an

gle

(d

eg

rees)

Time(s)

Matrix

5:20

5:40

5:60

Matrix + SAP Matrix + SAP + Lubricant

• Synergistic effect of API package, creates more ‘dynamic’ surface

• Absolute values of WCA change – weak correlation to field performance

• The presence of DCA behavior – strong correlation to field performance


XPS Confirms Stratification

C-C/C-H

C-O

High Resolution C1s Scan Depth Profiling


Formulation Prototype Library

with API

Characterization of Wetting

& Surface Properties

SAP-14 SAP-24

Synthesis

Formulation

Analysis

Biological ScreeningField Screening

SAP-14 SAP-24 (-) Control

Short-Term Field Screening

3 months in Port Canaveral FL

Laboratory Scale Rapid

Screening Studies

SAP-14

SAP-24

Stained bacterial biofilm

on coating surface

AST’s Approach: Rapid Throughput Testing (RTT)

Design & Synthesis of

Modular SAPs

SAP-14

SAP-24

Customized

with unique

groups

IP


Worldwide Field Testing Sites


Field Screening Test (Pt. Canaveral, FL)

“No Harm No Foul” quick screening barge

• Static exposure test

• Can hold up to 450 panels

• High fouling pressure

(best commercial FR fails <3 months)

• Some species show resistance to copper

paints (e.g. Interspeed BRA640)


AST’s Field Screening Study Method


Towards ‘Non-Fouling’ Coating

32 week

static study

Pt. Canaveral

Florida


Going Beyond Marine Paints

SAP

carrier particles SAP-modified particles

architectural coating interior coating medical device coating

lubricant

compounding

base resin


Conclusions & Outlook

• Successfully demonstrated the pathway to reducing marine fouling with a non-toxic,

environmentally-friendly approach combining the smooth and slippery liquid-based surface

(Physical module) and highly branched amphiphilic SAPs (Chemical module).

• Carefully designed and tested APIs can be introduced as additives to existing marine paint

systems or even other coating systems such as architectural paints, interior coatings, food

or medical coatings, etc. to impart anti-fouling properties.

• Such systems can still utilize conventional antimicrobial or antifungal agents as a new

hybrid approach, where as an added benefit, the concentration of active agents may be

reduced when synergistic effect is achieved.


Acknowledgment

DE-AR0000759

Stefan KolleProf. Joanna Aizenberg

Cathy Zhang, Onye Ahanotu,

Jack Alvarenga, James C. Weaver,

Tom Blough

Shane Stafslien

Prof. Dean Webster

Market Entropy

Illara Consulting

Liz Haslbeck

Eric Holms

Kody Liberman

Prof. Ali Miserez

Snehasish Basu

Address any questions to:

[email protected]

world leaders in repellent surfaces - pci mag...pccp 15 581-585 2013 nano lett. 13(4) 1793-1799 2013...

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