The Tip of the Iceberg: Nanoclays as a Raw Material

Nanoclays are a fascinating class of materials that have gained significant attention in various industries due to their unique properties and versatile applications. These nanoscale particles, typically composed of layered silicates, exhibit exceptional mechanical strength, thermal stability, and barrier properties.

Qualities of Nanoclays

Nanoclays possess several remarkable characteristics that make them highly sought after in manufacturing industries. One of their key attributes is their large surface area, which allows for enhanced reactivity and adsorption properties. This capability makes them ideal for use as catalysts, adsorbents, and reinforcement agents in composite materials.

Additionally, nanoclays exhibit excellent mechanical properties, such as high tensile strength and stiffness, and can also enhance the structural integrity of materials when incorporated as fillers or reinforcements.

Furthermore, nanoclays are known for their thermal stability, which enables them to withstand extreme temperatures without degradation or loss of their properties. This characteristic makes them valuable in applications that involve exposure to extreme temperatures, such as automotive components and fire-resistant coatings.

Another notable property of nanoclays is their exceptional barrier performance. Due to their layered structure, they can form an impermeable barrier against gases and liquids. This is particularly advantageous in packaging applications where the prevention of moisture, oxygen, and other contaminants is crucial.

Types of Nanoclays

There are several types of nanoclays available, each with its own unique structure and traits. The most commonly used types include:

Montmorillonite.

Due to its excellent adsorption capacity, montmorillonite is widely used in wastewater treatment, drug delivery systems, and soil stabilization.

Kaolinite.

A platy nanoclay that is widely used in the cosmetic industry as it provides an excellent matte finish and oil-absorbing properties, making it a popular ingredient in foundations, powders, and skincare products.

Halloysite.

A tubular nanoclay with a unique hollow structure which allows it to encapsulate and release active ingredients in a controlled manner - ideal for drug delivery systems and self-healing coatings.

Bentonite. Extensively used in the construction industry due to its excellent swelling and absorption properties, which make it effective in soil stabilization, drilling muds, and sealants.

However, beyond these widely known applications for nanoclays in manufacturing, nanotechnology researchers are discovering more and more versatility in this powerful class of nanomaterials.

“Essentially, nanoclays represent chemical building blocks designed with specific functions which are assembled into extremely thin, two-dimensional microscopic sheets — thinner than a strand of human DNA and 100,000 times thinner than a sheet of paper,” explains Baker Gary Baker, an associate professor in the Department of Chemistry at the University of Missouri. “We can customize the function and shape of the chemical components presented at the surface of the nanoclay to make whatever we want to build. We’ve just exposed the tip of the iceberg for what these materials can do.”

For example, each nanoclay can be adapted using various chemical elements, such as mixing and matching different sections. As a result, they can be used to create diagnostic sensors for biological imaging or in the detection of explosives and weapons.

A further, fundamental part of nanoclays’ versatility as a raw material for industry is its electrically charged surface.

“Imagine a koosh ball where the thousands of rubber strands radiating from the ball’s core each with an electrically charged bead on the end,” said Baker. “It’s analogous to a magnet — positively charged things will stick to negatively charged things. For instance, positively charged nanoclays could attract a group of harmful fluorinated chemicals known as PFAS, or ‘forever chemicals’ which are negatively charged. Or, by making the nanoclay negatively charged, it can stick to things such as heavy metal ions like cadmium, which are positively charged, and help remove them from a contaminated body of water.”

Nanoclays are so thin, they are technically thought of as two-dimensional. This puts them in great demand in industry as they can be used to coat the outside of a bulk material, such as a polymer, to introduce completely different surface properties to the object underneath.

Nanomaterials are revolutionizing various industries with their exceptional properties and versatile applications, and as research and development continue to advance in this field, manufacturers can expect to see even more innovative uses and materials leveraging the power of nanoclays.

As Baker notes, “By mixing and matching a few things like different ions or gold nanoparticles, we can quickly design chemistry that’s never existed before, and the more we tailor it, the more it opens a wider range of applications.”

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