NANOGARD: Smart Self-Cleaning Coating
- UM Research
- 1 day ago
- 5 min read
Introduction
The ubiquity of glass as a staple component in our lives is often regarded as solely a window of protection, a barrier, or even as trivial as kitchenware or decorative. In fact, how frequently do we ponder the elements that constitute a glass material, or why a stubborn stain on your glass panels never disappears despite laborious efforts to remove it?
Within the automobile detailing industry, approximately 30 car detailers reported problems with deep scratch marks and watermarks on customers' windshields due to wiper lining, road debris, and dust. Buffer chemicals used for polishing and grinding are costly and ineffective, as they remove only 50-80% of deep scratch marks, making them an uneconomical choice. Dust and debris accumulation on building glass and photovoltaic (PV) panels ultimately hampers their functionality as it reduces transparency.
With the advancement of technology and the evolution of the nano-coating industry, demand for self-cleaning coatings on glass panels, particularly within the photovoltaic (PV), automotive, and building construction industries, has shown surging interest and growth. Recognising these industrial dilemmas and investment opportunities, the research team led by Dr Amirul Syafiq Abdul Jaafar and his team from UM Power Energy Dedicated Advanced Centre (UMPEDAC), Universiti Malaya, proudly develops NANOGARD Self-Cleaning Coating that has both the invaluable properties of a self-cleaning mechanism and a protective mechanical barrier that prevents damage to glass panels.
Development of NANOGARD
Seamlessly embodying dualistic properties as a protective and self-cleaning barrier, NANOGARD introduces a coating consisting of nano Calcium Carbonate (CaCO3) particles and a water-repelling material - Polydimethylsiloxane (PDMS). The nano-CaCO3 particles create a rough-coated surface, with air pockets between the nanoparticles. The air pockets reduce the contact area between the contaminants and the glass substrate surface (Figure 1), creating an anti-dust surface. Ultimately, the synergistic combination of PDMS and nano-CaCO3 coating enables spherical water droplets to collect and slide dirt particles away from the glass surface, achieving the self-cleaning effect.
To put into perspective, the development of NANOGARD coating is likened to the structure of a lotus leaf (Lotus Effect), comprising nanostructures called papillae (Figure 2). These papillae reduce water adhesion to the lotus surface, thereby increasing the water-repelling surface properties. Hence, they allow the spherical droplets to slide off effortlessly when collecting any debris on their surface.
Status Quo into Current Self-Cleaning Coating Technologies
To understand the research project's key findings, it is essential to examine the current state of nanotechnology in developing self-cleaning products.
One concern in synthesising a tough coating that withstands cumulative damage is that damage to the organic layer of the coating can be attributed to environmental factors, such as exposure to UV light, Oxygen, heat, humidity, and pollutants. Several reports have discussed the impact of rain droplets and wear resistance on the adhesion of the coating. Although the study was conducted indoors, rain droplets were proposed to deliver water hammer pressure, which generates micro-cracks on coated surfaces, thereby hampering their water-repellent properties.
In addition, the limitations of current anti-dust coatings are their durability. The durability of the commercialised anti-dust water-repellent coating is commonly less than 6 months. Reduced durability indicates the coating's inability to maintain its self-cleaning effect in real outdoor environments. Additionally, the self-cleaning coating requires a technical and complex installation process involving a “wiping method”, which involves a long curing time of approximately 12-24 hours at ambient temperatures.
Discoveries & Insights into Field Tests
The NANOGARD self-cleaning test has been conducted in the lab and outdoor environments. SIRIM QAS conducted tests in a lab environment, utilising simulated dust particles (dust spray) within a vacuum chamber. It was reported that the NANOGARD coating achieves a lower dust haze value by 2.6%—3.5% under their standard self-cleaning test, BS EN 1096-5:2016. Due to its hydrophobic properties, the coating exhibits low adhesion to rain droplets, allowing dirt particles to be easily removed by rolling or sliding water droplets.
In terms of PV panel application, the NANOGARD coating can improve the performance of PV panel operation. The indoor and outdoor PV tests have been conducted in the UMPEDAC Solar Garden. After 3 months of outdoor exposure, the coated PV panel maintains its output voltage with a degradation rate of around 2%. Meanwhile, the bare PV panel (non-coated) shows a significant drop in output voltage of 16%. The efficiency of the PV panel showed an improvement, with the coated PV panel recording an efficiency of about 7.61% compared to the non-coated panel (5.89%) under indoor electroluminescence analysis. This indicates that the self-cleaning coating contributes to protective properties against heat accumulation, cracks, and wear on PV solar cells.
Drawing insights from the current self-cleaning coating market, NANOGARD was developed with enhanced features, including a 12-month durability under prolonged outdoor exposure. This property is enhanced using inert PDMS polymer, which strongly resists UV light and organic contamination. The PDMS polymer is comprised of a siloxane backbone that enhances the coating's adhesion to the glass substrate, hence forming a strong scratch-resistant protective barrier that resists loads of up to 5N (non-coated glass fails to resist scratch loads of 2 N).
The NANOGARD self-cleaning coating features a simpler installation process, which involves a straightforward spray method rather than a complex wiping process. After application, the coating is cured at ambient temperature in approximately 10-20 minutes.
In terms of sustainability, NANOGARD is expected to enhance the efficiency of solar panels by improving light absorption and reducing energy loss due to dirt and grime accumulation. This leads to higher energy output from existing solar installations, maximising clean energy generation and reducing reliance on fossil fuels. The clean PV panel can thus operate more efficiently with an extended operational period than non-coated PV panels. This long-lasting PV panel coating can generate continuous electricity with fewer replacements required over time, thereby reducing PV waste and the carbon footprint associated with manufacturing new panels.
Into the Future
Ultimately, NANOGARD has demonstrated significant potential in various applications across fields such as building maintenance, car detailing, and photovoltaic panel segments, with a projected market share of RM2.1 million. Currently, NANOGARD has been sold to car owners experiencing watermarks and dust accumulations on windshields, who have also expressed positive reviews and demand for durable water-repellent products that serve as a self-cleaning and protective mechanical barrier. Additionally, the product has been sold to PV maintenance companies, such as GreenXpert Sdn. Bhd. is responsible for industrial applications on their PV plant.
In the pursuit of NANOGARD, the research team has encountered difficulties in securing funding for the expansion of sales and marketing activities, the development of large-scale prototypes, and the enhancement of research activities in the UMPEDAC lab. Thus, to address the dilemma, the research team is currently establishing collaborations with industry partners to further promotional efforts and conduct research at industrial sites.
Conclusion
Ultimately, the development of NANOGARD presents not only an economic marvel for consumers and industrial users in maintaining glass panels but also serves as a champion of nanotechnology in its contributions towards sustainability and the efficient use of energy resources, as evidenced by the novel discoveries made by the research team led by Dr Amirul. The UM community congratulates the research team on their research pursuits!
Researcher Featured:
Dr Amirul Syafiq Abdul Jaafar
UM Power Energy Dedicated Advanced Centre (UMPEDAC)
For inquiries, please contact:
T: 03-22463413
Author:
Ms Eng Pink Huey
Pink Huey is currently a fourth-year medical student at the Universiti Malaya. Outside clinical wards, her enthusiasm for writing and classical music drives her appreciation for the harmonious union of art and life. For a tinge of adrenaline, she enjoys hiking and chasing sunsets!
Copyedit:
Siti Farhana Bajunid Shakeeb Arsalaan Bajunid, Assistant Registrar, UM
Nurhazrin Zanzabir, Assistant Admionistrative Officer, UM
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