Where have we taken nanotechnology?

When four nanotechnology enthusiasts founded the NANOPROGRESS cluster in 2010, they could not have foreseen how many important discoveries lay ahead — or how profoundly those discoveries would influence the industrial and healthcare sectors. From the very beginning, attention was focused on polymer materials and their transformation into nanofibers through electrostatic spinning. Soon after the cluster was founded, we managed to construct a device that was able to create nanofibers from a number of polymers using direct current. The key new patented element of this device was the so-called overflow electrode, which enabled the preparation of nanofibers from many synthetic polymers, such as polyamide, polyurethane, or polyvinyl butyral, but also from a number of biocompatible and biodegradable polymers such as polycaprolactone, polyvinyl alcohol, collagen and many others.

A significant innovation was the development of a spinning device for the preparation of coaxial, i.e. hollow nanofibers. These nanofibers can be made from biodegradable polymers and their cavity can be filled with, for example, drugs or other biologically active substances. This began the era of so-called functionalization of nanofibers, which, in addition to the properties given by the spatial structure of the fibers, adds other functional properties that significantly increase the added value of nanofibers. The ability to functionalize nanofibers has become a key research and development element of the NANOPROGRESS cluster, which has distinguished us from the vast majority of our competitors to this day.

As our research activities grew, in 2012 it became necessary to establish a specialized Laboratory of Advanced Nanofiber Structures, which is located in rented premises of the Technical University of Liberec. Thanks to the activities of this laboratory in 2014, two groundbreaking discoveries were made. It turned out that not only direct current (DC) electric current can be used to produce nanofibers, but that the spinning process works even better using alternating current (AC). It was the very limited productivity of DC spinning that severely limited its use for production operations. In contrast, AC spinning stands out with significantly higher productivity, while at the same time allowing to influence a number of process parameters and thus change the properties of the resulting nanofibers according to the target applications. This world-unique AC technology has become another key strategic research and development element of the cluster (patent protected) and the vast majority of our current production of nanomaterials comes from this technology. The second breakthrough discovery was the preparation of linear nanostructures. Until then, all nanomaterials were created in the form of a planar membrane and various densities and basis weights. We managed to come up with a technology where nanofibers are captured on a carrier fiber, thereby creating a nanofiber yarn. We can prepare these yarns from dozens of synthetic or biopolymers in many different diameters and they can be used directly or processed using conventional textile technologies, such as weaving, knitting, and others. This has fundamentally expanded the possibilities of applying nanofibers to other fields. 

We have worked tirelessly on the further development of AC spinning technology for both planar and linear structures, and especially in the possibilities of their advanced functionalization. In 2020, we managed to integrate so-called sputtering into the AC spinning process. Thanks to this innovation, we can incorporate and fix fine powder materials and particles into the interfiber spaces and thus create composite nanofiber structures. For example, activated carbon can be incorporated into a nanofiber filtration membrane, thus providing it with sorption capabilities in addition to the standard mechanical filtration function. The composite membrane prepared in this way is capable of removing an exceptionally wide range of unwanted particles and contaminants from both air and water.  

The driving force behind the research and development carried out within the NANOPROGRESS cluster has always been the synergistic involvement of cluster members in the R&D process at all levels of the value chain, from chemical and polymer synthetic producers, through analytical support, in-house researchers and developers of nanotechnology and spinning equipment, to the applicators of emerging solutions in commercial applications and products. It is thanks to intensive research and the involvement of many cluster members that we have managed to develop a number of unique technological solutions and products, which can be divided into three main groups: 

Biomedicine, healthcare and cosmetics

• Protective equipment - respirators, masks. Thanks to the global Covid pandemic, we have accelerated the development of protective equipment, where the nanofiber membrane ensures extremely high protection against viral and bacterial pathogens, while the functionalization of the fibers with biocidal substances (betadine) further enhances the protective effect and extends the useful life of the mask or respirator.
• Implantable nanofibrous carriers and wound dressings. Nanostructures made of biodegradable polymers functionalized with biologically active substances from stem cells for the treatment of bone, tendon, cartilage defects and skin injuries, where the nanofibers serve as a supporting matrix for cell growth, while also undergoing gradual biodegradation and thus gradually releasing active substances at the site of tissue damage, significantly increasing the regenerative effect.  
• Cosmetic masks based on nanofibers functionalized with active substances, vitamins, where the extremely large active surface of the nanofibers results in highly effective transport of active substances into the skin.

Environmental technology

• Nanofiber filtration membranes for water and air filtration, optionally functionalized by incorporating sorption, antimicrobial or antifouling components. These membranes are capable of very effectively removing both unwanted particles and pathogens, as well as contributing to the capture of a number of contaminants, or preventing the overgrowth of the filtration membrane with biofilm, which reduces filtration capabilities. 
• Nanofibrous carriers of bacterial biomass for water purification. Nanofibrous yarns processed into 3D carriers are an ideal environment for the growth of microorganisms that effectively degrade unwanted contaminants from water, including pesticides, drug and hormone residues, and other micropollutants.

Food and other industries

• Nanofiber filters for filtration of vegetable oils, wine, distillates and other media. Nanofiber-based filters provide high filtration efficiency and, thanks to higher permeability, also reduce energy costs. At the same time, these filters, thanks to the specific properties of nanostructures, also demonstrate quantum sorption effects and can, for example, eliminate unwanted phosphatides, pesticide residues and other substances from vegetable oils or wine, and thus significantly increase the sensory and nutritional quality of filtered foods in one process step.
• Intelligent textiles. Nanofiber textiles with incorporated electrically conductive component for protective clothing for explosive environments. Textiles with powdered activated carbon for protective clothing for environments contaminated with CBRN substances. Textiles with integrated nanofiber biosensors for the detection of specific substances.