Life cycle assessments (LCA) of an early research state reaction process only have laboratory experiments data available. While this is helpful in understanding the laboratory process from an ...environmental perspective, it gives only limited indication on the possible environmental impact of that same material or process at industrial production. Therefore, a comparative LCA study with materials that are already produced at industrial scales is not very meaningful. The scale-up of chemical processes is not such a trivial process and requires a certain understanding of the involved steps. In this paper, we elaborated a framework that helps to scale up chemical production processes for LCA studies when only data from laboratory experiments are available. Focusing on heated liquid phase batch reactions, we identified and simplified the most important calculations for the reaction step's energy use as well as for certain purification and isolation steps. For other LCA in- and output values, we provide estimations and important qualitative considerations to be able to perform such a scale-up study. Being an engineering-based approach mainly, it does not include systematically collected empirical data which would give a better picture about the uncertainty. However, it is a first approach to predict the environmental impact for certain chemical processes at an industrial production already during early laboratory research stage. It is designed to be used by LCA practitioners with limited knowledge in the field of chemistry or chemical engineering and help to perform such a scale-up based on a logical and systematic procedure.
•We developed a framework to scale up chemical processes from laboratory data for LCA studies.•Relevant and simplified calculations, estimates and considerations for heated liquid batch reactions are presented.•The framework is designed for LCA practitioners without an advanced knowledge of chemistry or chemical engineering.•The results allow a prediction of the possible environmental impact at a commercial scale for comparative LCA studies.•The results are helpful to improve the production process at an early development stage.
Not much is known so far about the amounts of engineered nanomaterials (ENM) that are produced but this information is crucial for environmental exposure assessment. This paper provides worldwide and ...Europe-wide estimates for the production and use of ten different ENM (TiO
2
, ZnO, FeO
x
, AlO
x
, SiO
2
, CeO
2
, Ag, quantum dots, CNT, and fullerenes) based on a survey sent to companies producing and using ENM. The companies were asked about their estimate of the worldwide or regional market and not about their company-specific production, information that they would be less likely to communicate. The study focused on the actual production quantities and not the production capacities. The survey also addressed information on distribution of the produced ENM to different product categories. The results reveal that some ENM are produced in Europe in small amounts (less than 10 t/year for Ag, QDs and fullerenes). The most produced ENM is TiO
2
with up to 10,000 t of worldwide production. CeO
2
, FeO
x
, AlO
x
, ZnO, and CNT are produced between 100 and 1000 t/year. The data for SiO
2
cover the whole range from less than 10 to more than 10,000 t/year, which is indicative of problems related to the definition of this material (is pyrogenic silica considered an ENM or not?). For seven ENM we have obtained the first estimates for their distribution to different product categories, information that also forms the base for life-cycle based exposure analysis.
Nepenthes pitcher inspired anti‐wetting coatings, fluoro‐SNs/Krytox, are successfully fabricated by the combination of fluoro‐silicone nanofilaments (fluoro‐SNs) and Krytox liquids, ...perfluoropolyethers. Fluoro‐SNs with different microstructure are grown onto glass slides using trichloromethylsilane by simply repeating the coating step, and then modified with 1H,1H,2H,2H‐perfluorodecyltrichlorosilane. Subsequently, the Krytox liquid is spread on the fluoro‐SNs coatings via capillary effect. The fluoro‐SNs/Krytox coatings feature ultra‐low sliding angle for various liquids, excellent stability, and transparency. The sliding speed of liquid drops on the fluoro‐SNs/Krytox coating is obviously slower than on the lotus inspired superhydrophobic and superoleophobic coatings, and is controlled by composition of the coating (e.g., morphology of the fluoro‐SNs, type of Krytox and its thickness) and properties of the liquid drops (e.g., density and surface tension). In addition, the self‐cleaning property of the fluoro‐SNs/Krytox coating is closely related to properties of liquid drops and dirt.
Nepenthes pitcher inspired anti‐wetting coatings are fabricated by the combination of fluoro‐silicone nanofilaments and a perfluoropolyether liquid. The sliding speed of liquid drop and the self‐cleaning property can be controlled by composition of the coating, properties of liquid drop, and dirt.
We assessed how the seasonal variability of precipitation δ2H and δ18O is propagated into soil and xylem waters of temperate trees, applied a hydrological model to estimate the residence time ...distribution of precipitation in the soil, and identified the temporal origin of water taken up by Picea abies and Fagus sylvatica over 4 yr.
Residence times of precipitation in the soil varied between a few days and several months and increased with soil depth. On average, 50% of water consumed by trees throughout a year had precipitated during the growing season, while 40% had precipitated in the preceding winter or even earlier. Importantly, we detected subtle differences with respect to the temporal origin of water used by the two species.
We conclude that both current precipitation and winter precipitation are important for the water supply of temperate trees and that winter precipitation could buffer negative impacts of spring or summer droughts.
Our study additionally provides the means to obtain realistic estimates of source water δ2H and δ18O values for trees from precipitation isotope data, which is essential for improving model-based interpretations of δ18O and δ2H values in plants.
A superhydrophobic and photocatalytic composite fiber material is developed using polystyrene polydimethylsiloxane and graphitic nitride and then thoroughly characterized. SEM is used to determine ...the nanostructure of the fiber material, and the contact and sliding angles are measured to test the obtained fibers for their hydrophobicity. The degradation of methylene blue is used to monitor the photocatalytic activity of the created materials. This serves to create a self‐cleaning surface where hydrophilic pollutants are repelled from the surface due to the low sliding angle; the lower‐surface‐tension pollutants resist wetting the surface and can be thoroughly washed off; and photocatalytical oxidation can degrade pollutants that fully wet the fabric, allowing the surface to recover.
An electrospun composite material consisting of polydimethylsiloxane, polystyrene, and graphitic nitride is developed and optimized for hydrophobic properties (contact and sliding angle) and photocatalytic activity (degradation of Methylene Blue). This is then tested for its combined ability to repel hydrophilic nonwetting pollutants, retain partially wetting pollutants until they are washed off and recover the clean surface after being fully wetted.
Superhydrophobic textile fabrics are prepared by a simple, one‐step gas phase coating procedure by which a layer of polymethylsilsesquioxane nanofilaments is grown onto the individual textile fibers. ...A total of 11 textile fabrics made from natural and man made fibers are successfully coated and their superhydrophobic properties evaluated by the water shedding angle technique. A thorough investigation of the commercially relevant poly(ethylene terephthalate) fabric reveals an unparalleled long‐term water resistance and stability of the superhydrophobic effect. Because of the special surface geometry generated by the nanoscopic, fibrous coating on the microscopic, fibrous textiles, the coated fabric remains completely dry even after two months of full immersion in water and stays superhydrophobic even after continuous rubbing with a skin simulating friction partner under significant load. Furthermore, important textile parameters such as tensile strength, color, and haptics are unaffected by the silicone nanofilament coating. For the first time, an in‐depth characterization of the wetting properties, beyond simple contact angle measurements, as well as a thorough evaluation of the most important textile parameters is performed on a superhydrophobic fabric, which reveals a true potential for application.
In a simple, one step procedure a large variety of textile materials can be coated with silicone nanofilaments. The resulting surface geometry that consists of micro‐ and nano‐fibrous structures generates superhydrophobic properties with an extraordinary robustness towards long‐term water exposure and abrasion. An in‐depth characterization of a coated poly(ethylene terephthalate) fabric reveals no significant influence of the coating on important textile related properties such as color, tensile strength, or haptics.
Superhydrophobic and superoleophilic polyester materials are successfully prepared by one‐step growth of silicone nanofilaments onto the textile via chemical vapor deposition of ...trichloromethylsilane. The successful growth of silicone nanofilaments is confirmed with scanning electron microscopy, energy‐dispersive X‐ray analysis, and investigation of the wetting behavior of water on the textile. Even microfibers deeply imbedded inside a woven material could be coated very well with the nanofilaments. The coated textile is water repellant and could only be wetted by liquids of low surface tension. The applications of the coated textile as a membrane for oil/water separation and as a bag for selective oil absorption from water are studied in detail. Owing to the superwetting properties and flexibility of the coated textile, excellent reusability, oil/water separation efficiency, and selective oil absorption capacity are observed, which make it very promising material, e.g., for practical oil absorption.
Superhydrophobic and superoleophilic polyester materials are prepared by one‐step growth of silicone nanofilaments onto the textile via chemical vapor deposition of trichloromethylsilane. Owing to the superwetting properties and flexibility of the coated textile, excellent reusability, oil/water separation efficiency and selective oil absorption capacity are observed, which make it a very promising material, e.g., for practical oil absorption.
Niobium-doped TiO2 films as highly transparent conducting oxides for electrical contacts were investigated. As-deposited films were amorphous and exhibited high resistivities ranging from 10 to ...105Ωcm. A slight oxygen deficiency in as-deposited films was essential to gain low resistivities (10−3Ωcm) and low optical absorption coefficients (α550nm<2×103cm−1) in the annealed films. Therefore, we controlled the oxygen stoichiometry during the film deposition by adjusting the magnetron discharge voltage, while the oxygen gas flow was kept constant. The Hall mobility of degenerately doped films (electron concentration>1020cm−3) increased with decreasing substrate temperature owing to metal-like phonon scattering in these samples.
•Slight oxygen deficient as-deposited films were highly conductive after annealing.•Control of oxygen stoichiometry by adjusting the discharge voltage during deposition•Electron mobility at room temperature is limited due to scattering at phonons.•Films exhibited large average crystallite sizes with planar structural defects.
A new technique is introduced to evaluate the wetting properties of superhydrophobic textiles which are not accessible by classical contact angle measurement techniques. The principle behind the new ...water shedding angle technique is the ability of a superhydrophobic surface to repel drops of water upon impact. In this sense it shows a strong reference to application and its results are easily understood in terms of water protection. The procedure is simple and straightforward and the experimental setup can be easily built or adapted to most available contact angle measurement systems. In view of the significant potential of superhydrophobic coatings for textile applications, the water shedding angle provides a reliable and comparable measure to judge the quality of a superhydrophobic textile in terms of water repellency. It constitutes a useful addition to existing techniques and has proven to be better suited to evaluate the wetting properties of superhydrophobic textiles than the contemporary methods presently in use.
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