Sustainable Nanotechnology. Группа авторов

economy is facing the most critical problem, which is availability of clean water. Continuous supply of potable water for humans and in food processing, in energy generation, and in many more industries is a major challenge in many parts of the world. The combination between nanotechnology and water science technology revolutionizes the advancement in water treatment, purification, and recycling technologies [47]. Today, the available techniques for water purification are reverse osmosis or vapor compression. The available technologies for treatment of water have many limitations to provide sufficient quality to meet the requirements of humans and the environment. Hence, it is mandatory to reuse water after its exit from industry; also, we can recycle it, and it can be repurposed. Swaminathan et al. have developed nanofluidic systems that consist of membranes containing nanocapillary scale of 1 to 100 nm composed of polycarbonate sheet with measurement of 6–10 μm. The authors emphasized the effect of pore geometry, charge density, and surface charge to regulate the movement of ions or charged particles in nanopores. The authors focused on the addition of nanocapillary membrane into nanofluidic system that can manage the transport of molecules from one chemical environment to another [48]. Park et al. describe nanofibers as membrane for nanofiltration, which are made up of polyvinylidene fluoride (PVDF) and polyethyleneimine (PEI) for fabrication using electrospinning techniques with improved performance of nanofiltration for purification of water [49]. Usually, nanoadsorbents are very effective in eliminating pollutants from wastewater. Ali studied the benefit of using nanoadsorbents for treatment of wastewater due to its special properties such as very small size with larger surface area having lots of active sites for binding, which gives ease of separation [50]. Today, polymeric nanoadsorbents are more promising due to their excellent adsorption capacity and thermal stability in all pH range [51].

      2.3.3 Food Science Technology

      Recent advances in nanotechnology have made diverse applications in food technology possible, which include food safety, food additives, nanodelivery systems, biosecurity, and nanotoxicity. Health benefit and quality of food is a major concern for consumers, without reducing nutrition benefits. Due to the availability of many required elements with less‐toxic effect of NMs, the demand of NMs is continuously growing in food science [52]. In nanoencapsulation of various components such as vitamins, lycopene, and lutein, many naturally occurring colors can be used as a tool for the delivery of various additives. By nanoencapsulation, spoilage and microbial contamination can be prevented in the food product. It also improves shelf life while improving safety of the food product [53]. Bratovčić et al. have emphasized on the improvement of sustainability of agrifood using nanotechnology by controlling microorganisms for decreasing the wastage of food and increasing the safety of food [54].

      Fernandez et al. have worked with carotene protection using nanofibers of zein by encapsulation to increase its stability to oxidation with the help of nontoxic solvents such as dimethyl formamide and chloroform, which makes it sustainable [55]. In nanoencapsulation, there is a direct contact of NMs with food during consumption, e.g. silicon dioxide (SiO₂) is mostly used as a carrier for fragrance of food products [56]. Many lipid‐based formulations that are nanoencapsulated were developed to increase the effectiveness of antioxidants with its bioavailability and solubility [57]. One study showed that nanosized edible coating is a versatile solution for extension of shelf life of food and minimization of spoilage [58].

      2.3.4 Sustainability of Aquaculture

Nanotechnology can revolutionize fisheries and aquaculture industry by rapid detection of disease with enhancement of various drugs absorption capacity of fish. Many approaches focus on the prevention of disease in aquatic species. For instance, the use of oil emulsion in vaccine may reduce side effects to a minimum. There is an availability of many inorganic nanocarriers based on carbon or calcium for fish vaccine. Carbon‐based inorganic materials have good stability but have many limitations. Because of its variable chemical properties, it can be used as a carrier for vaccine delivery [59]. Liu et al. demonstrated the use of nanopolyplexes for DNA vaccine carrier in fish, which is made up of oleoyl‐carboxymethyl‐chitosan in hyaluronic acid for its more physiological stability. NMs used for fish vaccine should be safe because fish are eaten by humans who eventually consume the NMs that remain intact in fish.. Generally, NMs used for vaccine for fish need to be safe for both fish and humans [60].

      2.3.5 As Nanobiopesticide

      Nowadays, there is an increase in environmental hazard due to insecticides, and limitation in the synthesis of novel, safe, and effective molecules has increased the demand of research in this field. Nanosilica with amorphous property can be an effective carrier for better functional pesticide. Insects protect themselves from dehydration using cutical lipids and prevent death of the pest. By the mechanism of physical absorption, the nanosilica absorbed into the cuticular lipid causes killing of insects and pest. As per World Health Organization (WHO), the use of amorphous form of silica is safe for oral consumption for humans [61, 62]. Spinosad is a newly developed environmentally friendly biopesticide with limitation of having short duration of action and less potency in farm. Zhang et al. worked with novel nanospinosad that uses porous NPs for loading of spinosad. This nanospinosad exhibits rough surface texture, which makes it unique for high adhesion behaviors of pest, which also gives high mortality rate of pest with improved photostability in fields [63].

      2.3.6 Conservation of Work of Art

      Nowadays, work of art is mainly made up of organic materials such as acrylic polymer, which are difficult to remove during cleaning. However, this organic polymer needs to be removed from work of art composition. Nanotechnology comes up with versatile solutions that provide unique solutions by decreasing degradation of work of art materials and also can achieve long‐term sustainability of artistic heritage. This approach can be beneficial for unstable materials that are used by modern artist. Some frequently occurring issues in conventional method of reestablishment can be overcome by nanoproducts such as nanofluids that consist of microemulsions [64]. Kolman et al. emphasize on an approach that combines two materials for canvas preparation such as silica NPs treated with polyelectrolyte and nanofibrils made up of cellulose. It was seen that using this combination had strengthening effect for fibrous material such as paper and also improvement in stiffness compared to individual components [65].

      2.3.7 Plant Protection Using Nanofibers

      Pheromones are a chemical substance generally released by female insects in the environment to attract male insects. Now, these pheromones are used in farm to protect crops from insects and as an alternative to chemical hazards of insecticide to soil. Generally, these pheromones are spread in the farm to prevent mating of insects, thus ultimately reducing their population by confusing male insects [66]. Hellmann et al. have studied the use of nanofibers as carriers using polyamides and cellulose acetate for pheromones. The ideal requirement of nanofibers for this purpose is high porosity and large surface. It was observed that solubility of pheromones is higher in cellulose acetate and gives more loading compared to polyamide nanofibers. The release of pheromones can be observed up to 30–50 days, depending on the material used, which minimizes washout due to rain with long‐lasting effect [67]. Ponmurugan et al. had carried out a study of red root rot disease on tea plant. They compared nano‐CuO with bulked CuO for antifungal effect on tea plant, which is a disease caused by Poria hypolateritia fungus. They found that nano‐CuO gives more reduction in fungal growth with high yield in terms of leaves [68].

      2.3.8 Management of Greenhouse Effect

      Since past 10 years, increase in pollution from vehicles and industries has increased emission of greenhouse gases such as CO₂, which leads to global warming. Although many alternative sources are being developed that are non‐CO₂ emitting, the world will continue to use substantial amounts of fossil fuels in the future. The upcoming alternative for excess CO₂ released in the atmosphere is the use of carbon capture and storage using nanotechnology, which gives efficient and cost‐effective separation of CO₂ [69]. Initially, conventional membranes with polymeric structures were used for separation of CO₂ due to its low