SoC Presentation Title 2004

Recycling Plastic Waste into High-Value Added Aerogels for

Novel Applications

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Team members

PIs: A Prof Hai M Duong and Prof Nhan Phan-Thien

Collaborator: Dr. Wendy Xiwen Zhang, SimTech

RE Duyen Khac LeFYP student Ryan Leung Hoe Inn

SoC Presentation Title 2004

OIL SPILL IN CHENNAI

Singapore threw out 815,200 tonnes of plastic waste in 2017

SCENARIO

SoC Presentation Title 2004

OIL SPILL IN CHENNAI

PLASTIC WASTE SOLUTION IN SINGAPORE

“We would like to clarify that NEA do not allow plastic waste to be dumped in Malaysia as NEA regulates and license companies dealing in the collection, transport and processing/treatment of waste.

Of the 815,200 tonnes of plastic waste generated in 2017, only about6% were being recycled. The plastic waste that was not recycled wasincinerated at our waste-to-energy incineration plants. Though someof the sorted plastics are processed locally into resins but most arebaled for export overseas where there are proper facilities to furtherprocess them into raw materials or products.

The import of water from the Johor River Waterworks (Malaysia) is managed by PUB who operate a water treatment there to meet our portable water quality.”

Senior Engineer • Environment Technology Department • National Environment Agency

SoC Presentation Title 2004Making PolyEthylene Terephthalate (PET) Fibers from Plastic Bottle Waste

• This commercial equipment from Germany, costing ~$20K SGD,can produce with some control on the PET fiber morphology

• Recycled PET fibers can be purchased from commercial market

Recycled PET fibers

SoC Presentation Title 2004The World’s First Aerogel Made from Recycled

PET Fibers (from Plastic Waste)

SoC Presentation Title 2004Summary of Recycled PET Aerogel Process

Recycled PET fiber was dipped and swelled in polyvinyl alcohol (PVA) or PVA/glutaraldehyde (GA)/H2O mixture, and then sonicated under 400 W power for 30 minutes

Reaction mixture was cured in over at 80oC for 3 hours at pH~3 (controlled by Hydrochloric acid – HCl)

Gelation done by freezing in refrigerator at -18oC overnight or nitrogen liquid in few minutes

Ice is taken out by freeze drying or ambient drying processes to produce the PET aerogels

(i) One A4-size aerogel sheet (30 × 20 × 1 cm3) can be made

from 1 plastic bottle (13 g); and (ii) 1 ton of fibers can make 80,000

pieces.

SoC Presentation Title 2004Novelty of Recycled PET Aerogel Process

SG Non-Provisional Application No. 10201802587W, PolyethyleneTerephthalate (PET) Aerogels, filed on 29 March 2018“Advanced Recycled Polyethylene Terephthalate Aerogels from Plastic Waste forAcoustic and Thermal Insulation Applications”, GELS, in press (May 2018)

Cheap and abundant recycled PET fibers can be used to produce aerogels for the first time

Dichloromethane (DCM) or methylene chloride can be used to produce finer and softer PET fibers (~cotton fibers) if necessary

New cross-linkers such as tetraethyl orthosilicate (TEOS)/ethanol mixture and PVA/glutaraldehyde (GA)/H2O mixture can be used

New and cost-effective aerogel fabrication technique using ambient pressure drying or freeze drying methods – scaleable

PET Aerogels Coated with Different Chemicals through simple but effective low-heating method for different novel applications

SoC Presentation Title 2004Various Applications of PET Aerogels

Thermal jacket /insulated

garment

Heat and sound insulation

Oil and non-polar liquid absorptionPackaging and others

CO2 Filtering PET Aerogel

SoC Presentation Title 2004Sound Insulation Performance of

PET aerogel (PSA)

Sound absorption coefficient of PET aerogel is better than best commercial basmel, hardwood, corksheet materials

Effects of PET fiber amount Effects of PET aerogel thickness

SoC Presentation Title 2004Fire Retardant Ability of PET Aerogel Coated with

Silica

It can stand up to 620oC

SoC Presentation Title 2004Oil Absorption Performance of

PET Aerogel Coated with Methyl Groups

Fast oil absorption within 1 minute. Oil absorption ability is 70.2 g/g, about 3X better than commercial sorbents.

Super-hydrophobic after coating with TMCS (trimethylchlorosilane) or MTMS (MethylTriMethoxySilane)

30.0

40.0

50.0

60.0

70.0

80.0

90.0

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Oil

ab

sorp

tio

n c

apac

ity/(

g/g

)

PET wt%

Effects of PET fiber amount

SoC Presentation Title 2004CO2 Uptake of PET Aerogel Coated with Amine Groups of

3-aminopropyltrimethoxysilane (APS)

It can absorb 22-66 g CO2 /kg (0.5-1.5 mmol CO2/g) from ambient

SoC Presentation Title 2004

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Potential Markets

• Sorbents market for cleaning oil spills: $143.5 billion dollars

• Heat and sound insulation market: $3.3 billion dollars

[1] http://ecobasalt.com/the-market/; [2] Comparative Energy Evaluation of Plastic Products and Their Alternatives for the Building and Construction Industry Franklin and Associates, 1992; [3] https://www.grandviewresearch.com

Cost comparison for oil & gas, building & construction industries

A 30× 20× 1 cm3 PET

aerogel sheet manufacturing

costs a few dollars

SoC Presentation Title 2004

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ADVANCED PROPERTIES OF PET AEROGELS Ultra lightweight due to their very low density (0.02 g/cm3) Super-hydrophobicity with MTMS coating (149.9o) Very low thermal conductivity like air (0.033 W/m.K) High oil absorption with MTMS coating (49.5 g/g) Very elastic (compressive Young’s modulus = 4.98 kPa) With fire retardant and silica coating, they can stand up 620oC Good sound insulation with absorption coefficient of 0.45.

With coating amine groups at 90oC, they absorb 0.5 -1.5 mmol/g of CO2

Aerogel structure is very stable & self cleaning (super hydrophobic).

With NUS President, Prof. Tan Eng Chye

SoC Presentation Title 2004

THANK YOU