Scientists from the Innovation in Materials and Molecular Engineering-Biomaterials for Regenerative Therapies (IMEM-BRT) research group at the Polytechnic University of Catalonia (UPC) are working on the development of a thermosensitive hydrogel material that would have desalination among its most notable applications. of seawater with solar radiation and the creation of new biomedical stickers for semi-invasive therapies and for medical diagnosis.
The pilot tests carried out so far, within the framework of the TherGel project, show that the system that incorporates the new hydrogel "has obtained an evaporation rate of around 3.5-4.5 kg/square meter per hour, which would represent about 80 -100 kg/square meter of clean water generated in 24 hours", highlights the UPC. Preliminary results have recently been published in the scientific journal Advanced Functional Materials.
The UPC highlights the importance of the application of the new hydrogel in the field of desalination, recalling that "according to UN estimates, three out of every four people in the world will be affected by drought in 2050, a problem that currently affects around 55 million people directly each year". This situation will worsen in the coming decades due to the lack of rain and the effects of climate change, with serious damage in the environmental, economic and social spheres, indicates the university in a note disclosing the preliminary results of its researchers.
The development of low-cost technologies for the purification and desalination of seawater, with 100% organic materials and taking advantage of a natural resource such as solar radiation, is one of the key strategies to satisfy the current and future needs for water suitable for domestic consumption, those responsible for the investigation highlight.
To solve this challenge, the TherGel project is developed, led by Elaine Armelin and Joan Torras, researchers from the Innovation in Materials and Molecular Engineering - Biomaterials for Regenerative Therapies (IMEM-BRT) research group and professors from the School of Engineering of Barcelona East (EEBE) of the Polytechnic University of Catalonia - BarcelonaTech (UPC).
The project focuses on developing a conductive thermosensitive hydrogel, called solar absorbing hydrogel (SAH). Thermosensitive hydrogels are polymeric materials capable of absorbing a large amount of water, depending on the temperature to which they are exposed, and expelling it free of salts and contaminants, when heated above 32ºC. A conductive polymer is added to this material that acts as a photothermal absorber and enhances the water expulsion capacity, that is, the generation of drinking water.
According to researcher Elaine Armelin, “the result is a material that can be used in water filtration systems such as filtration membranes and capacitive deionization systems for salt water. The objective is to develop a prototype of self-purification of water for its application directly in homes, without the need for electrical sources or pressure equipment, since it would only use solar energy for the regeneration of saline water and the production of drinking water.
Researcher Joan Torras explains how this technology works: “As the hydrogel absorbs water, this water rises to the surface and evaporates due to the action of sunlight. To this material we add nanoparticles of a conductive polymer, which gives the material a more intense black color, so that it absorbs more solar radiation and at the same time favors the evaporation of water internally. “It is a small desalination plant to produce drinking water at home.”
So far, the system has obtained an evaporation rate of around 3.5-4.5 kg/square meter per hour, which would represent about 80 -100 kg/square meter of clean water generated in 24 hours. Preliminary results have recently been published in the scientific journal Advanced Functional Materials.
We could make the hydrogel at home, with a kit to prepare it, since it does not require any industrial equipment, and we could also reuse or recycle it at home. Furthermore, the good electrical properties of the new conductive hydrogel make it potentially attractive in capacitive deionization (CDI) cells, such as porous electrodes, to increase the generation flow rate of purified water. In this case, as an alternative material to those usually used in industrial desalination equipment, which are high cost and very difficult to recycle.
The property of thermosensitive hydrogels to retain liquids and respond to changes in temperature makes them ideal for application in medical implants, such as surgical meshes for the repair of abdominal hernias, sponges for the drainage of fistulas, after surgical procedures and bandages. for wounds, among others. This is the second challenge of the TherGel project.
The presence of hydrogel in surgical meshes, for example, facilitates their adaptation to the tissues due to the adhesion capacity of the material and the possibility of detecting the implant using surface enhanced Raman spectroscopy (SERS, Surface Enhanced Raman Spectroscopy). acronym in English). As the researcher from the IMEM-BRT research group Sonia Lanzalaco explains, “during the implantation phase, the hydrogel is capable of self-opening to adapt to the temperature of the human body, and, once implanted, it can provide information about the changes temperature caused by a possible localized infection. Thanks to this hydrogel, the mesh could adapt better to the organs, both in flexibility and biocompatibility.”
The researchers have applied biocompatible nanoparticles to the surgical mesh that have a therasnostic function, that is, both therapeutic and diagnostic: on the one hand, they act as bactericides and, on the other, they allow the detection of the implant with spectroscopy tools that are less invasive for cells. , enabling more personalized therapies to the needs of each patient. Furthermore, as it is a self-adhesive mesh, the need to use staples, plugs or sutures for fixation is avoided, reducing inflammatory risks.
The TherGel technological innovation project is financed by the State Research Agency (AEI) with a budget of 138,545 euros and has a duration of three years.
