Category Archives: Materials

Coloured Contact Lenses: Do They Bring More Harm than Good?

Are you thinking about wearing coloured contact lenses to change the colour of your eyes? While it may appear to be a simple and risk-free way to enhance your natural eye colour or make a fashion statement, it is critical to consider the chemical composition as well as the potential risks associated with these lenses. Let’s look at the chemistry of coloured contact lenses and weigh the upsides and downsides.

Better Vision different colour contact lenses. Source.

Reasons Against Coloured Contact Lenses:

They Increase the Risk of Eye Infections: Contact lenses are made of hydrophilic polymers, which attract and retain water. This makes them an ideal surface for microorganisms to grow on, increasing the risk of eye infections. If you do not clean and disinfect your coloured contact lenses properly, you may increase your risk.
Common monomers and polymers used in contact lens production. PMMA—poly methyl methacrylate, PVA—poly vinyl alcohol, PEG—poly ethylene glycol, DMA—dimethyl methacrylate, HEMA—hydroxy ethyl methacrylate, NVP—N-vinyl pyrrolidone, EGDMA—ethylene glycol dimethacrylate, PDMS—poly dimethyl siloxane, TRIS—3-[tris(trimethylsiloxy)silyl]propyl methacrylate. Source
Manufacturers Might Not Follow Strict Safety Standards: Coloured contact lenses are frequently regarded as cosmetic devices and are therefore not subject to the same regulations as medical devices. Some manufacturers may fail to adhere to strict safety standards, resulting in poorly made lenses that harm your eyes. It is critical to select a reputable brand and avoid purchasing lenses from untrustworthy sources.
Sharing Coloured Contact Lenses is a Big No-No: Sharing coloured contact lenses or wearing them for an extended period of time can increase the risk of eye infection. This is because the lenses can harbour bacteria, which can cause long-term damage to your eyes. It is critical to carefully follow the instructions and avoid sharing your lenses with anyone.

Reasons in Favour of Coloured Contact Lenses:

Different coloured contact lenses in the same individual. Source.

They Allow Personal Expression: Coloured contact lenses are a fun and versatile way to express yourself and your sense of style. You can switch up your look as often as you like because there are so many different colours and designs to choose from. This is especially appealing to those who do not want to commit to long-term solutions such as cosmetic surgery or tattoos.
They Are Made of Safe Materials: Coloured contact lenses are made of eye-safe materials such as silicone hydrogels or methacrylate-based polymers. These materials are designed to be biocompatible, which means they will not harm or irritate your eyes.
They Can Be Customized to Your Needs: Coloured contact lenses are available in prescription and non-prescription forms, allowing you to tailor them to your specific requirements. This is especially beneficial for people who need vision correction but want to experiment with different eye colours.

Finally, while coloured contact lenses can be a fun and exciting way to experiment with your personal style, it is critical to prioritize your eye health and safety. You can reduce your risk of eye infections and enjoy the benefits of coloured contacts by selecting a reputable brand, following proper cleaning procedures, and avoiding sharing your lenses. Whether you’re looking to enhance your natural eye colour or completely change your look, remember to prioritize your eye health and enjoy your new look with confidence!

~ Vivian Hou

Acrylic Nails: Are They Worth the Damage?

Among young adult and teen women, acrylic nails have become a popular trend. Despite the range of nail designs possible through acrylic nails, this beauty routine is hotly debated due to exposure to toxic chemicals.

What are acrylic nails?

Long and Complex nail designs can be achieved using acrylic nails (credit: Bvasilev1, Wikipedia Commons)

Acrylic nails are a form of nail extensions that use a liquid and powder formula to create a sturdy fake nail. The powder contains poly(methyl methacrylate), also known as acrylic glass. Acrylic glass is a type of synthetic plastic polymer. This polymer gets activated when in contact with the liquid monomer used in acrylic nail formation. This liquid contains ethyl methacrylate (EMA) and an inhibitor. The inhibitor prevents immediate polymerization between the liquid and powder. The polymer powder is dipped into the monomer to create a malleable bead that is shaped to fit the client’s nail. Within minutes of application, the mixture cures, forming a solid layer.

The debate against acrylic nails

Many health experts argue against the use of acrylic nails due to the harsh chemicals used in their creation. EMA is particularly concerning. Particles of this highly reactive monomer are likely to remain unpolymerized after the nail has cured. This can cause redness, swelling, and pain in the customer’s nail bed. The reactivity and negative effects of monomers have been discussed at length. Prior to EMA, methyl methacrylate (MMA) liquid monomers were used. MMA has since been banned by the Food and Drug Administration due to severe damage to nails and allergic reactions.

Acrylic nails often use chemicals such as toluene, phthalates, methacrylic acid, and formaldehyde. These chemicals have been proven to cause asthma, allergic reactions, short-term memory loss, and irritate eyes, throat, and lungs.

The effects of these chemicals on clients’ nails and overall health have made acrylic nails a debated service. This argument also extends to nail technicians who are surrounded by these chemicals every day.

Acrylic nails can cause damage to the natural nail when not applied or removed by a professional (credit: Pickpik)

The pros of acrylic nails

Despite some backlash regarding the chemicals used in acrylic nails, many people continue to advocate for this practice due to its strength, cost, and appearance.

The hard layer formed by the polymer and monomer serves as protective over the nails. When applied by professionals, acrylic nails can be used to protect natural nails. This is especially helpful for customers with brittle or weak nails.

Acrylic nails also last for up to 21 days, decreasing the number of times customers must return to the nail salon. In the long run, acrylic nails can be a cost-effective way for customers to continue looking their best.

Lastly, acrylic nails provide unmatched customizations for their clients. Customers can choose from a range of lengths, shapes, colours, and designs.

As showcasing creativity via nail designs becomes more popular, customers stay aware of the potential health concerns that surround their beauty regimen.

-Carissa Chua

Environmental Hazard to Reusable Material: Converting Plastics and CO2 into Fuel

Plastic waste management has become a serious issue over the last few decades. In 2019, the total amount of plastic produced since 1950 totaled just over 9.5 billion tons, and plastic production hasn’t slowed down, as 400 million tons were added to that in 2020.

The chemical bonds that make up plastics are hard to break and do not degrade in the environment quickly. This makes plastic waste challenging to deal with, leading to a large amount of plastic being discarded or incinerated.

While people have been recycling since the late 1980s, only about 6% of annual waste is recycled, and only a further 20% of that stays recycled. Current recycling methods consist of mechanical recycling, a process by which the plastic is ground or melted down into a new product, or chemical recycling, a process by which chemical additives break down the plastic into more manageable pieces to be used as raw material. However, both methods are not environmentally friendly or cheap, leading to a high volume of plastics that are not recycled (see below).

The final fate of plastics over 65 years. only 1.72% of plastics remain recycled.

Finding new ways to deal with plastic waste is a heavy focus for environmental scientists, leading to catalysis, electrochemistry, and photochemistry developments. One such method, developed by Dr. Resier and his team at the University of Cambridge, has found a way to deal with this waste in an environmentally clean way. Using a perovskite (PVK) based photocathode and a copper-palladium alloy anode in combination with a CO2 reduction catalyst, they transformed PET plastics and CO2 into a variety of useable fuels and by-products, such as carbon monoxide, hydrogen gas, and glycolic acid.

Electrochemical pathway of CO2 reduction into CO and byproducts.

The photoelectrochemical system works upon sunlight exposure under zero applied voltage and generates products 10-100 times faster than other catalytic methods. Further, the catalyst system is not sensitive to the introduction of bio-organic molecules; in fact, the presence of small amounts of food products could increase the activity of the system.

However, this process is anything but cheap. The copper-palladium alloy anode is not cheap to fabricate, and the materials required are rare, palladium being over 15 times rarer than platinum. This increases startup costs, which is not favorable to most companies who could instead dump the waste.

While advancements in this technology are still needed, there is a positive outlook for the future of plastics and environmental contaminants. We may yet be able to save our fragile, yet vital planet from our own advancement.

Tristan Ruigrok

Nanocrystals: The Science Behind Creamy Plant-Based Ice Cream

Ice cream lovers, get ready to indulge in a whole new level of creamy goodness! The secret ingredient? Nanocrystals.

These tiny particles, smaller than the width of a human hair, have the potential to revolutionize the world of vegan ice cream. Typically less than 100 nanometers in size, they can be made from a variety of materials, including cellulose, starch, and lipids. And here’s the exciting part: they can make vegan ice cream creamier than ever before!

Figure 1. Vegan vanilla ice cream. Source.

Traditionally, guar gum and locust bean gum (LBG) are the most commonly used stabilizers in ice creams. Recent research, however, suggests that cellulose nanocrystals (CNCs) may provide a more effective alternative. CNCs play an important role in improving the texture of plant-based ice cream by preventing ice crystal formation. This is due to nanocrystals’ unique properties which prevent them from growing larger. This results in a smooth and creamy texture comparable to traditional ice cream that consumers with dietary restrictions can enjoy.

But how do nanocrystals work their magic? The answer lies in the physics of freezing. When the water molecules in ice cream freeze, they can form large ice crystals. These large crystals, with diameters larger than 50 μm, impart a grainy texture to ice cream and can make it less creamy. Nanocrystals, on the other hand, can prevent this by enclosing the ice crystals in a protective shell, slowing their growth and keeping them small.

Figure 2. Ice growth kinetics of 0.5% CNCs, guar gum, and LBG in 25% sucrose solutions. Adapted from source.

Figure 2 shows that CNCs at 0.5% concentration can completely stop ice crystal growth after 72 hours. This is a significant finding because the same concentrations of guar gum and LBG had different effects. In the presence of CNCs, the final ice crystal size was approximately 37 μm, which was smaller than the final crystal size in the presence of guar gum and LBG. These findings show that CNCs can be a more effective stabilizer than traditional ones, as they can prevent ice crystal growth and result in smaller ice crystal sizes.

Smaller ice crystals can improve the creaminess, smoothness, and mouthfeel of ice cream.

It’s amazing how such small particles can have such a big impact on the quality of plant-based ice cream. Take a moment to appreciate the incredible chemistry happening in your bowl the next time you enjoy a scoop of your favourite non-dairy treat.

~ Vivian Hou

Are Your Non-Stick Pans Casing Celiac Disease?

Recent discoveries suggest persistent organic pollutants (POPs) may increase the likelihood of celiac disease, especially in females.

What is celiac disease?

Celiac disease is an autoimmune disorder where the small intestine reacts negatively to the wheat protein (gluten) in foods containing white, rye, and barley. The current solution for celiac disease is to follow a gluten-free diet. Celiac disease is believed to be genetic, however, some research suggests a possible environmental connection.

Research from the New York University School of Medicine found that high levels of Persistent organic pollutants (POPs) in blood samples correlate to an increased likelihood of a celiac disease diagnosis.

POPs are toxic chemicals generated by human activity. Examples of POPs include polybrominated diphenyl ether (PBDEs), perfluoroalkyl substances (PFASs), and p,p’-dichlorodiphenyldichloroethylene (DDE). These pollutants are found in all aspects of daily human life and serve many purposes, as shown in Table 1.

Table 1: Common POPs’ Location and Function

Spraying pesticides on bananas in the 1980s | Location: Big … | Flickr

Pesticides used in fruit farming occasionally contain DDE (Credit: Scot Nelson, Flickr)

In a study of 88 patients from NYU Langone’s Hassenfeld Children’s Hospital outpatient clinic, blood samples were measured for the aforementioned POPs. Subsequent testing for celiac disease was also performed and resulted in 30 patients receiving positive results.

As seen in figure 1, the concentration of POPs in patients with celiac disease is slightly higher than in “healthy” patients. When age, BMI, sex, and genetic predisposition are accounted for, DDE was correlated with a two-fold increase in celiac disease diagnosis.

Figure 1: PBDE, PFAS, and DDE Median Concentrations in Celiacs vs. Non-Celiacs. These bar graphs compare the median blood concentrations of various POPs in patients diagnosed with celiac disorder and non-celiacs. Notably, this figure does not account for age, sex, genetic predisposition, and BMI. (Credit: Carissa Chua, Modified from Gaylord, et. al.)

When separated by sex, PFAS pollutant concentration was found in higher concentrations in females with celiac disorder. Similarly, men with celiac disorder displayed higher levels of PBDEs. While this discovery is interesting, a more thorough, sexually stratified study should be performed using a greater sample size.

Gluten free bread | ????????Professional Photographer ????Twitch C… | Flickr

Attempting to avoid these pollutants may complement a gluten-free diet (Credit: Marco Verch, Flickr)

Continued exploration into the interaction between POPs and celiac disease should be performed to definitively prove any relationship. However, attempting to cautiously avoid toxic pollutants as mentioned above may be a helpful addition to a gluten-free diet.

-Carissa Chua

Breaking Down Plastic, One Worm at a Time

A 2022 study by Sanluis-Verdes et al. has found that wax worm saliva is able to break down plastic in just a few hours.

The researchers collected saliva from Galleria mellonella worms and applied it to polyethylene (PE) films. After a few hours, the films had visibly deteriorated and analysis of the films determined that the plastic had oxidized and released additives, evidence that it had degraded.

Credit: Catherine Sheila

Generally, plastics require decades or even centuries to completely degrade through natural exposure to the environment. Because of humanity’s high consumption of plastic, simply dumping them in landfills or waterways only leads to an accumulation that smothers habitats and leaks toxic substances into the soil and water.

This makes finding a safe and quick way of breaking down plastic crucial for sustainable waste management.

Scientists in recent years have been particularly interested in biodegradation, in which naturally-produced enzymes from bacteria, fungi, or animals are used to decompose plastic.

However, scientists have only identified a handful of enzymes that are capable of this, and these enzymes still require years to degrade plastic. They are unable to accomplish the first step of degradation – oxidizing the polymer – and still rely on exposure to UV light and other environmental factors to do it, which usually takes years.

Currently known process of plastic degradation. Credit: Rebecca Yang

Sanluis-Verdes et al.’s experiment demonstrated that the enzymes in wax worm saliva are in fact able to accomplish this crucial step under normal physiological conditions – room temperature, neutral pH, typical background levels of UV – in just a few hours rather than years. The researchers identified an increased presence of ketones in the PE after only applying the saliva a few times, proof that it had been oxidized by the enzymes alone.

The researchers also tried to identify the enzymes responsible. They were able to pick out two enzymes in the saliva that had a significant effect on PE degradation. Until now, it was believed that bacteria in the gut of wax worms were primarily responsible for plastic degradation, but this discovery indicated that it was the wax worms themselves that oxidized and broke down PE enough for it to then be completely decomposed by bacteria. The researchers also noted that the two enzymes were functionally different from known bacterial enzymes. This suggests that there may be other methods of biodegradation than what is currently known for bacteria.

The exact mechanism will require further studies to determine. If this can be identified and if the enzymes involved can be easily extracted or mass produced, using the enzymes found in wax worms may become a feasible way to naturally and quickly manage plastic waste.

The Gore-Tex Enigma

Gore-Tex is a highly versatile material that has garnered a lot of publicity in recent years.

Gore-Tex Logo

It is a magical material in many respects. Water simply glides off it, leaving it bone dry. Being also very breathable and light, it is no surprise that it is the ideal material for water resistant clothing.

First invented in 1968 by Wilbert and Robert Gore, it is made of polytetrafluoroethylene, more commonly known as Teflon. Not the hard stuff though. It’s basically Teflon that has been stretched… a lot.

With the likes of Adidas and Nike incorporating it into their outdoor wear products, its worldwide use and popularity has called into question the manufacturing process and its environmental impacts.

Teflon is a very durable material that does not degrade easy and lasts for a long, long time. This is a good thing right? Well, yes… But what happens when that fifteen year old jacket you own is discarded or lost, and finds itself buried in the dirt outside an abandoned parking lot?

It persists. And doesn’t degrade. For centuries.

PFC’s or perfluorinated compounds are those that contain only carbon and fluorine atoms. Teflon is made from these compounds.

Chemical structure of Teflon: repeating units of carbon and fluorine atoms

The problem with PFC’s is that they tend to accumulate within our bodies and the environment. They are difficult to break down as they are quite unreactive.

A class action lawsuit at a DuPont Teflon plant found a very strong association between working with PFC’s and two types of cancer. Since then, many other studies have found a correlation between exposure to certain PFC’s and negative health outcomes.

To be clear, it isn’t the wearing of Gore-Tex products that is concerning. Also, not all PFC’s are harmful. However, the manufacturing process dispels many harmful PFC’s into the environment.

Gore-Tex jackets are also near impossible to recycle. They are made in complex ways, and the design process involves multiple layers, glues, and components.

Gore-Tex must not be completely written off though. Gore and company have assured investors and the public that they are stopping the use of many harmful PFC’s in their manufacturing process. However, the effects of this are yet to be seen.

There are also other, more intriguing applications of this remarkable material.

What is not talked about nearly enough is the role of Gore-Tex in medicine. It has shown to be ideal for use inside our bodies.

Being so unreactive, it allows the body’s cells and tissues to grow through it without any side effects. This makes it a viable material for many medical applications.

Like most technologies, Gore-Tex is complicated in many ways. Its strengths in one regard prove to be its downfall in another. It seems the jury is still out on this one

– Salik Rushdy

Enzymes – A Solution in the War Against Plastics

It should not be a surprise to people that it can take over 500 years for UV radiation – light from the sun to break down a piece of plastic. But what if there is a faster way to break down single-use plastics?

Researchers at the University of California, Berkeley invented a new way to decompose consumer plastics in a short amount of time, simply with heat, water, and nano-dispersed enzymes.

Plastic waste covering the shoreline. Source

UC Berkeley professor Dr. Ting Xu and her research group developed a nanoscale enzyme that can eat away at the polymers in plastics. These nanoscale polymer-eating enzymes can be embedded into plastics during manufacturing. The enzymes were wrapped around plastic resin beads. These beads are melted and can be manufactured into single use consumer plastics. To prevent the enzymes from activating when not required, a random heteropolymer (RHP) coating is applied to hold enzymes without restricting the flexibility of tensicity of the plastics.

Xu likened this process to organic composting. By adding water and heat, the RHP polymers is removed and starts eating away the polymers into smaller subunits.

The research conducted by Xu and her group found that the enzymes took about a week to degrade most of the plastics. Polylactic acid (PLA) and polycaprolactone (PCL) based plastics embedded with nanoscale polymer eating enzymes are able to break down the polymer chains into smaller molecules, such as lactic acid.

Plastic cups made from biodegradable plastics. Source

It is clear there is still more research needed in this field. Currently, Xu is developing other modified RHP-wrapped enzymes that can stop the degradation process at specific points in it’s degradation so that the polymers can be recycled into new plastics.

“[Humans] are taking things from the Earth at a faster rate than we return them,” said Xu. “Don’t go back to Earth to mine for these materials, but mine whatever you have, and then convert it to something else.”

As consumers, we can play an important role reducing our consumption on single use plastics and create a more sustainable environment for ourselves and future generations.

Raymond Tang

A Breakthrough in Nuclear Fusion

On December 5th 2022, scientists at the Lawrence Livermore National Laboratory (LLNL) in the United States successfully created the reaction that powers the sun – nuclear fusion ignition – for the first time in human history.

The announcement was made by the US Department of Energy on December 13th. Described as a “historic, first-of-its-kind” achievement, the event has excited the scientific community because of its potential as a clean energy source.

Inside the LLNL’s National Ignition Facility, where the experiment took place. Credit: LLNL

To achieve ignition, the scientists had constructed “the world’s most energetic laser”, consisting of 192 powerful laser beams. This laser was used on a small canister containing the compounds deuterium and tritium, causing the compounds to fuse together. The reaction generated 3.15 megajoules of energy from an input of 2.05 megajoules, a markup of 54%.

After over 60 years since researchers first began to study nuclear fusion, this result finally proved that controlled fusion that produces more energy than it consumes is possible.

Depiction of fusion: deuterium(D) and tritium(T) fuse to form the larger Helium(He) and release energy. Credit: US Department of Energy

Nuclear fusion is the process that allows the Sun to emit vast amounts of energy in the form of light and heat. It involves the joining of two atoms of a lighter element to form a heavier one, releasing energy in the process.

Compared to nuclear fission, which is how nuclear power plants generate energy, fusion is much more powerful. It is also much cleaner as it does not produce radioactive materials as a byproduct.

Because of this, many believe that nuclear fusion is a promising avenue for sustainable and eco-friendly energy in the future. However, there is still a long way to go until fusion can be viable for commercial use.

When asked to comment on the time needed, Kim Budil, the director of the LLNL, stated that “It’s probably two or three decades. Scaling from where we are today to what you would require for a power-generating plant is a pretty significant challenge.”

Director Kim Budil at the announcement of the achievement of ignition on December 13th, 2022. Credit: Mary Calvert/REUTERS

For the 8000 engineers, physicists, and chemists at the LLNL, this event is just the first step. Researchers will have to find ways to conduct nuclear fusion that are faster and cheaper, while also generating much more power. According to Budil, “What we need now is a scientific and investment strategy that allows us to make progress on all of these fronts simultaneously… [because] we need gain of a few hundred [megajoules] to make an energy system.”

Despite the many challenges ahead, Tim Luce, one of the leaders of the international fusion research project ITER, remains hopeful. “A result like this will bring increased interest in the progress of all types of fusion, so it should have a positive impact on fusion research in general,” he states.

The Gore-Tex enigma

Gore-Tex is a highly versatile material that has garnered a lot of publicity in recent years.

Gore-Tex Logo. Credit: https://commons.wikimedia.org/w/index.php?title=User:GoreTex&action=edit&redlink=1

With the likes of Adidas and Nike incorporating it into their outdoor wear products, its widespread use and popularity has called into question the manufacturing process and its environmental impacts.

Teflon is a very durable material that does not degrade and lasts for a long, long time. This is a good thing right? Well, yes… But what happens when that fifteen year old jacket you own is discarded or lost, and finds itself buried in the dirt outside an abandoned parking lot?

It persists. And doesn’t degrade. For centuries.

PFC’s or perfluorinated compounds are those that contain only carbon and fluorine atoms. Teflon is derived primarily from such compounds.

Chemical structure of Teflon: repeating units of carbon and fluorine atoms. Credit: https://commons.wikimedia.org/wiki/User:Alhadis

The problem with PFC’s is that they tend to accumulate within our bodies and the environment. They are difficult to break down as they are quite unreactive.

A class action lawsuit at a DuPont Teflon plant found a very strong association between working with PFC’s and two types of cancer. Since then, numerous other studies have found a strong correlation between exposure to certain PFC’s and negative health outcomes.

To be clear, it isn’t the wearing of Gore-Tex products that is concerning. Also, not all PFC’s are harmful. However, the manufacturing process dispels many harmful PFC’s into the environment.

Gore-Tex jackets are also near impossible to recycle. They are made in complex ways, and the design process involves multiple layers, glues, and components.

Gore-Tex must not be completely written off though. Gore and company have assured investors and the public that they are phasing out the use of many harmful PFC’s in their manufacturing process. However, the effects of this are yet to be seen.

There are also other, more intriguing applications of this remarkable material.

What is not talked about nearly enough is the role of Gore-Tex in medicine. It has shown to be ideal for usage within our bodies.

Being both porous and unreactive, it enables the body’s cells and tissues to grow through it without any side effects. This makes it a viable material to be used in sutures, grafts and other applications.

Like most technologies, Gore-Tex is exceedingly complicated in many ways. Its strengths in one regard, prove to be its downfall in another. It seems the jury is still out on this one

– Salik Rushdy