La plata, muy usada para acuñar moneda, es bien conocida a lo largo de la historia por sus propiedades desinfectantes e silver, widely used to coin currency, is also well known throughout history for its disinfectant properties ble sweating can cause significant discomfor t, both the physi- cal and emotional. The problem of size was overcome with the arrival and deve- lopment of nanotechnology (science of the small).The “nano” is a dimension: 10 to -9.That is, 1 nm = 0.000000001 meters. A nanometer is a billionth of a meter, or one millionth of a mi- llimeter.Thus, in a millimeter would fit, placed on line, an ‘army’ of one million nanometers. It is the greatness of the tiny. Al- though we should not get carried away by the ardor of nano- science which, near its beginning, is still a beautiful rose full of thorns. Odor, a consequence of sweat Nano-particles of silver: nano-weaving has begun Skin bacteria thrive in the warm, moist environment of our clothes led by sweat.When the bacteria reproduce they rele- ase gases that are responsible for the perspiration odors. By treating the fabric with antimicrobial we prevent the bacteria that are transferred from the skin or the environment to re- produce on the clothes (bacterial growth is neutralized). Ob- viously, the reduction of bacteria means a diminution in the gas volume given off, reducing the associated odor. Some clothing, such as socks and underwear, has been treated with antibacte- rial for many years. Textile technology is already able to incorporate nano-silver particles to polypropylene to develop antimicrobial material capable of use in everything from carpets to napkins, clothing or surgical masks. The control of bacteria, fungi and mites can be achieved using textile finishing techniques, an added value with a strong de- mand by the consumer. Antimicrobial products can control odors, discoloration, staining and degradation, which are the result of microbial attack on textiles. The polypropylene fiber is one of the most widely used synthetic fibers in the textile industry because it is cheaper and stronger than other synthetic fibers. Researchers have shown, as published in the July issue of Polymer International, that they can produce two types of fibers with nano-silver particles dis- tributed uniformly in the fiber. Scientists at Hanyang University in Seoul (Korea) have used the nano-silver particles to maximize surface area and thus in- crease the antibacterial effect.They were also able to confirm the finding that the fibers containing silver in their core had no antimicrobial activity. However, those containing silver in its outer part showed an excellent antimicrobial effect.This cha- racteristic is maintained even if the fibers have a low content of silver particles, without affecting also the physical properties of the fiber, which does not limit its field of application. Anticipating the future, we can state that the debate of the de- cade will be the effectiveness (in terms of durability) of the fa- bric supplemented with nano-silver particles. In other words, how long will the particles remain intertwined with the fabric? Do nano-particles detached from the fabrics have any adverse Regardless if the fiber is natural or artificial, the industry em- ploys several methods: incorporation of antibacterial and anti- fungal substances in the spinning process, application and fitting of antibacterial and antifungal substances on the surface of the fiber by a specific treatment, which usually follows the spinning process; or modification of the polymer itself and application of bio-active substances. The addition of antimicrobial agents in polymers is a common practice.They are added to protect them from degradation by microbes or to provide antibacterial properties to the outer surface of textiles. Antimicrobial additives based on silver (me- tallic or ionic state) are gaining prominence over the rest due to its bactericidal efficacy against a broad range of organisms. Alternative biocide agents such as copper are also used. 69 Enlightened the problem (sweating) and, before we get into possible solutions, we will clarify that there are two possible approaches to the problem: using biocides against the sweats’ products, or acting in an early stage of managing (limiting the quantity and facilitating their rapid evacuation or exchange with the atmosphere). Reports and Surveys Silver, the most antique of disinfectants The ability of silver to keep food and drinks fresh and pure has been recognized since the early years of civilization, long be- fore the existence of bacteria was known. A century ago, with a greater understanding of the role of bacteria in our environ- ment, experiments were initiated to improve medical treat- ment with the antibacterial power of silver. However, the price of the metal and the technical difficulties to reduce it to the size of microscopic particles limited its application. Silver has proven medically its lethal effectiveness against 650 disease-causing organisms, besides being very safe. Combining silver and polypropylene to create an organic-inorganic fiber, researchers have developed an antimicrobial fiber with a wide field of use. JOBWEAR 61 2o TRIMESTRE 2012