The wide array of applications of ceramic nanoparticle processing

This might very well be the age of semiconductors and nanoparticles. Even though we cannot see them with the naked eye, nanoparticles are everywhere. Beyond the nano dust particles floating in the air we breathe, fabricated nanoparticles can be found in sunblock creams, handwashes, solar cells, eyewear glasses, fabrics, paints, coatings, additives, and cosmetics with liposomal or micellar additives. They are also used in bike frames reinforced with carbon nanotubes, improved vehicle chassis stiffness, and semiconductors in electronic devices. Additionally, these nanoparticles play a crucial role in modern medications and drug delivery systems. Among these, ceramic nanoparticles stand out due to their unique ability to enhance properties like strength, thermal conductivity, and durability in various applications.

Nanoparticles can generally be synthesized from any element on the known periodic table. As technology advances towards tighter tolerances to facilitate newer inventions, more efficient manufacturing processes and equipment must be utilized to meet these demands. This progress drives the need to deeply understand particle characteristics and their natural morphologies to design particles with special features that extend beyond their natural limitations.

In this article, we’ll dive deeper into ceramic nanoparticles and their wide-ranging applications.

Additive manufacturing, or 3D printing, uses nanoparticles to layer nano-powdered material. This concept might seem futuristic, but it closely mirrors ideas from movies like Star Trek. The “replicator” in those films isn’t far-fetched; our current 3D printing technology is a basic version of that idea.

Imagine losing your phone and simply printing an exact replica in your living room. The new phone would have the same precise tolerances as the original, which was also 3D printed. This scenario could become a reality as technology advances. Furthermore, scientists are exploring molecular assembly with lasers instead of micro-mirrors and liquid resin.

What seemed like science fiction three decades ago is becoming reality today. So, where could nanoparticles and 3D printing take us in the next thirty years? If fully expanded, 3D printing could transform manufacturing and global economics. It holds the potential to reshape how we produce and consume products.

However, for now, we face challenges with particle characteristics and limitations. These obstacles prevent the full realization of this emerging technology. Yet, advances in nanoparticles continue to become the cornerstone of every major manufacturing industry. As we overcome these challenges, the possibilities for 3D printing will expand even further.

Throughout history, humans have continually sought to develop new materials and miniaturize them. This pursuit allows us to better understand and control their inner workings. Driven by curiosity, we naturally strive to learn how things function. Once we gain this knowledge, we apply it to practical innovations.

In the 1960s, researchers shifted focus from macron-sized particles to micron-sized ones. This change gave scientists and industries more flexibility in exploring particle science. By the 1980s, the invention of the scanning tunneling microscope expanded possibilities even further. This breakthrough unlocked access to an even smaller world of particles, paving the way for advances in nanotechnology.

Today, all materials can be processed to exhibit nanoparticle characteristics, though some are more advantageous than others. Ceramics, derived from the clay mineral kaolin, are particularly versatile. Industries widely use ceramics, either entirely or in part, for various applications. They play essential roles in chemicals, cosmetics, 3D printing, plastics, and pharmaceuticals. Ceramics also serve as additives in paper processing, paints, and tires, where they help reduce wear and extend product life.

Manufacturers typically create ceramics by applying heat to processed clays or powders, forming rigid products. However, when ceramic components are built from nanopowder particles, they open up new manufacturing possibilities. These nanoparticles offer enhanced properties like increased strength, durability, and improved thermal conductivity. Additionally, small ceramic particles are more chemically reactive than their larger counterparts, allowing for greater flexibility in achieving specific characteristics while maintaining the same composition.

The porosity of these nanoparticles also provides a larger surface area, which can be tailored to perform in specialized ways. This advantage proves beneficial in various applications. For instance, in pharmaceuticals, ceramic nanoparticles serve as nanocarriers that can deliver drugs to specific cells. They can even be designed to bind precisely to targeted cell receptors, improving treatment effectiveness and precision.

Powder technology plays a vital role in most industries, especially where precise product specifications require meticulously designed particles. It is a crucial aspect of nano ceramic manufacturing. Ceramic nanoparticles typically consist of metal carbonates, carbides, calcium, titanium, silicon, phosphates, and metal oxides. To isolate these particles, manufacturers must carefully process them.

The process begins with kaolin, a hydrated aluminosilicate clay also known as China clay. Kaolin offers favorable properties, making it ideal for pharmaceutical applications. Its flat particle shape, soft texture, and chemical inertness make it a versatile material for multiple industries, particularly in pharmacology.

Kaolin is abundant and extracted using open-cast surface mining. After extraction, the clay is blended with water or dispersing agents to form a slurry. This slurry then undergoes further processing through wet ball milling or vibratory milling. These methods reduce particle size by physically separating the ceramic minerals from unwanted byproducts, known as gangue material. Gangue material often contains elements like coal, zeolite, and mica, which can be repurposed for other industries. During separation, manufacturers may also use bleaching to enhance the product’s quality.

The next steps involve degritting and fractionating the clay using centrifugal sizers. Afterward, the ceramic powder is dried, and any necessary additives or binding agents are mixed in. These additives improve the powder’s flowability and ease of use during component fabrication. Binding agents, for example, help hold the shaped ceramic powder together after compaction.

The conversion of ceramic nanopowder into the desired shape involves various methods such as casting, injection molding, 3D printing, or die compaction, which often requires a releasing agent. Once shaped, the ceramic is known as a “green ceramic.” To finalize the product, the green ceramic undergoes sintering, which solidifies the shape and creates a fully functional item.

All manufacturing processes face contamination risks, and ceramic powder production is no exception. Ceramic powders are characterized by their size distribution, composition, particle size, morphology, and flowability. Contaminants can enter at various stages, whether during processing, shaping, or handling.

Contaminants can come from different sources. For instance, binder additives and releasing agents in dies may introduce impurities. Dust and foreign particles can also enter during powder processing and shaping. These contaminants significantly impact the final product’s density, consistency, morphology, and overall quality.

Binder additives, in particular, can cause clumping or introduce air bubbles in the finished product. These issues may lead to potential structural weaknesses, compromising the product’s durability and performance.

Unlike formative and subtractive manufacturing methods, 3D printing builds highly complex shapes using engineered data from a designed 3D model. It constructs these shapes layer by layer, adhering to precise design specifications and allowable tolerances. These tolerances are crucial for achieving intricate designs that would be challenging with traditional methods. By allowing for tighter control, 3D printing reduces the risk of product rejection due to inaccuracies.

Currently, there are five primary methods for 3D printing ceramics: extrusion, nanoparticle jetting, binder jetting, photopolymerization, and powder laser sintering. Each method typically involves injecting ceramic powder paste, resin, or liquid suspensions through nozzles to build up layers. These processes often include binding agents, and sometimes, releasing agents. However, regardless of the method, sintering remains essential to solidify the printed ceramic parts.

In the pharmaceutical industry, ceramic parts offer significant advantages over traditional metal components. For instance, replacing metal machine parts with ceramic ones helps equipment withstand high temperatures, pressures, and stresses more effectively. Unlike metal parts, ceramic components last longer and reduce both machine downtime and replacement costs.

Ceramic nanoparticles also play a crucial role in drug delivery. Aluminum oxide and titanium dioxide-based ceramics, for example, serve as carriers or vehicles for targeted drug delivery. These nanoparticles have noninvasive physicochemical properties and adaptive morphologies. As a result, they can be engineered to perform specific tasks, such as targeted cancer therapy or enzyme denaturing, enhancing their effectiveness in various biological functions.

Ceramic nanoparticles find applications across diverse industries, including aviation, aerospace, chemicals, semiconductor manufacturing, mechanical engineering, welding technology, fabrics, oil and gas, foundries, pharmaceuticals, additive manufacturing, battery production, and optical lasers.

Nanotechnology offers a way to improve product utility and enhance sustainability. Specialized ceramic nanoparticles possess several favorable properties, such as high heat resistance and chemical inertness. Their continuous porosity, large adaptable surface area, and superior thermal shock resistance unlock numerous possibilities. These attributes make ceramic nanoparticles versatile for various demanding applications.

Among all these fields, the biomedical sector is at the forefront of ceramic nanoparticle research. In this area, nanoparticles are commonly used as carriers for genes, proteins, and cancer drugs. With continued advancements, the future holds even more possibilities. Imagine a time when every home has a 3D printer capable of printing an entire phone in minutes. Or a doctor might be able to send a custom-made prescription directly to your home 3D printer.

The field of particle sciences promises exciting innovations for future generations. And all of it begins with a single particle.