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Decamethylcyclopentasiloxane
Decamethylcyclopentasiloxane, also known as D5 and D5, is an organosilicon compound with the formula . It is a colorless and odorless liquid that is slightly volatile. It is used in various cosmetic products. It also is used as a dry cleaning solvent and has been marketed as an "eco-friendly" and "green" alternative to perchloroethylene in the 2000s, under the tradename GreenEarth. Decamethylcyclopentasiloxane is persistent in nature and possibly bioaccumulative. Decamethylcyclopentasiloxane is considered non-toxic but its long-term health effects are unknown. Use The compound is classified as a cyclomethicone. Such fluids are commonly used in cosmetics, such as deodorants, sunblocks, hair sprays and skin care products. It is becoming more common in hair conditioners, as it makes the hair easier to brush without breakage. It is also used as part of silicone-based personal lubricants. D5 is considered an emollient. In Canada, among the volume used in consumer products approxim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclomethicone
In organosilicon chemistry, a siloxane is an organic compound containing a functional group of two silicon atoms bound to an oxygen atom: . The parent siloxanes include the oligomeric and polymeric hydrides with the formulae and . Siloxanes also include branched compounds, the defining feature of which is that each pair of silicon centres is separated by one oxygen atom. The siloxane functional group forms the backbone of silicones , the premier example of which is polydimethylsiloxane (PDMS). The functional group (where the three Rs may be different) is called siloxy. Siloxanes are manmade and have many commercial and industrial applications because of the compounds’ hydrophobicity, low thermal conductivity, and high flexibility. Structure Siloxanes generally adopt structures expected for linked tetrahedral ("''sp''3-like") centers. The Si−O bond length is 1.64 Å (vs Si–C distance of 1.92 Å) and the Si-O-Si angle is rather open at 142.5°. By con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octamethylcyclotetrasiloxane
Octamethylcyclotetrasiloxane, also called D4, is an organosilicon compound and one of a number of cyclic siloxanes (cyclomethicones). It is a colorless viscous liquid with a high boiling point. It has historically been used on a large scale in personal care products including cosmetics, hair conditioners and emollients (moisturising creams), Global production in 1993 was 136,000 tons, however it is now facing significant pressure from regulators. It is a substance of very high concern In the EU, where it was classified as a PBT and effectively banned in personal care products in 2018. The US EPA began reevaluating its risks in 2020. Replacements include branched-chain alkanes (isoparaffins). Production and polymerization Commercially D4 is produced from dimethyldichlorosilane. Hydrolysis of the dichloride produces a mixture of cyclic dimethylsiloxanes and polydimethylsiloxane. From this mixture, the cyclic siloxanes including D4 can be removed by distillation. In the presence of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dry-cleaning
Dry cleaning is any cleaning process for clothing and textiles using a solvent other than water. Clothes are instead soaked in a water-free liquid solvent (usually non-polar, as opposed to water which is a polar solvent). Perchloroethylene (known in the industry as "perc") is the most commonly used solvent, although alternative solvents such as hydrocarbons, and decamethylcyclopentasiloxane are also used. Most natural fibers can be washed in water but some synthetics (e.g., viscose) react poorly with water and should be dry cleaned if possible. If not, this could result in changes in texture, strength, and shape. Additionally, certain specialty fabrics, including silk and rayon, may also benefit from dry cleaning to prevent damage. History The ancient Greeks and Romans had some waterless methods to clean textiles, involving the use of powdered chemicals and absorbent clay ( fuller's earth). By the 1700s, the French were using turpentine-based solvents for specialized clea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicone
In Organosilicon chemistry, organosilicon and polymer chemistry, a silicone or polysiloxane is a polymer composed of repeating units of siloxane (, where R = Organyl group, organic group). They are typically colorless oils or elastomer, rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking utensils, thermal insulation, and electrical insulation. Some common forms include silicone oil, silicone grease, grease, silicone rubber, rubber, silicone resin, resin, and Caulking, caulk. Silicone is often confused with one of its constituent elements, silicon, but they are distinct substances. Silicon is a chemical element, a hard dark-grey semiconductor, semiconducting metalloid, which in its crystalline form is used to make integrated circuits ("electronic chips") and solar cells. Silicones are compounds that contain silicon, carbon, hydrogen, oxygen, and perhaps other kinds of atoms as well, and have many very different physical and chemical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dry Cleaning
Dry cleaning is any cleaning process for clothing and textiles using a solvent other than water. Clothes are instead soaked in a water-free liquid solvent (usually non-polar, as opposed to water which is a Solvent#Solvent classifications, polar solvent). Perchloroethylene (known in the industry as "perc") is the most commonly used solvent, although alternative solvents such as hydrocarbons, and decamethylcyclopentasiloxane are also used. Most natural fibers can be washed in water but some synthetics (e.g., viscose) react poorly with water and should be dry cleaned if possible. If not, this could result in changes in texture, strength, and shape. Additionally, certain specialty fabrics, including silk and rayon, may also benefit from dry cleaning to prevent damage. History The ancient Greeks and Romans had some waterless methods to clean textiles, involving the use of powdered chemicals and absorbent clay (fuller's earth). By the 1700s, the French were using turpentine-based s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunblock
Sunscreen, also known as sunblock, sun lotion or sun cream, is a photoprotective topical product for the skin that helps protect against sunburn and prevent skin cancer. Sunscreens come as lotions, sprays, gels, foams (such as an expanded foam lotion or whipped lotion), sticks, powders and other topical products. Sunscreens are common supplements to clothing, particularly sunglasses, sunhats and special sun protective clothing, and other forms of photoprotection (such as umbrellas). Sunscreens may be classified according to the type of active ingredient(s) present in the formulation (inorganic compounds or organic molecules) as: * Mineral sunscreens (also referred to as physical), which use only inorganic compounds (zinc oxide and/or titanium dioxide) as active ingredients. These ingredients primarily work by absorbing UV rays but also through reflection and refraction. * Chemical sunscreens, which use organic molecules as active ingredients. These products are sometimes re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Environmental Science & Technology
''Environmental Science & Technology'' is a biweekly peer-reviewed scientific journal published since 1967 by the American Chemical Society. It covers research in environmental science and environmental technology, including environmental policy. ''Environmental Science & Technology'' has a sister journal, '' Environmental Science & Technology Letters'', which publishes short communications. The editor-in-chief of ''Environmental Science & Technology'' is Prof. Julie Zimmerman (Yale University). Previous editors have been: David Sedlak (University of California, Berkeley, 2014 - 2020), James J. Morgan (California Institute of Technology; founding editor, 1967–1975), Russell F. Christman (University of North Carolina, 1975–1987), William H. Glaze (University of North Carolina, 1987–2003) and Jerald L. Schnoor (University of Iowa, 2002–2014). Abstracting and indexing According to the ''Journal Citation Reports'', the journal has a 2022 impact factor of 11.4. The journal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar System as Earth's North Pole. Due to Earth's axial tilt of 23.439281°, there is a seasonal variation in the lengths of the day and night. There is also a seasonal variation in temperatures, which lags the variation in day and night. Conventionally, winter in the Northern Hemisphere is taken as the period from the December solstice (typically December 21 UTC) to the March equinox (typically March 20 UTC), while summer is taken as the period from the June solstice through to the September equinox (typically on 23 September UTC). The dates vary each year due to the difference between the calendar year and the Year#Astronomical years, astronomical year. Within the Northern Hemisphere, oceanic currents can change the weather patterns that aff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ECHA
The European Chemicals Agency (ECHA; ) is an agency of the European Union working for the safe use of chemicals. It manages the technical and administrative aspects of the implementation of the European Union regulation called Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH). ECHA is the driving force among regulatory authorities in implementing the EU's chemicals legislation. ECHA has to ascertain that companies comply with the legislation, advances the safe use of chemicals, provides information on chemicals and addresses chemicals of concern. It is located in Helsinki, Finland and is operational since 2007. ECHA is an independent and mature regulatory agency established by REACH. It is not a subsidiary entity of the European Commission. The agency is headed by Executive Director Sharon McGuinness. Establishment The ECHA was created by European Union regulation dating from 18 December 2006 to manage the then-new legislation to regulate the man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Economic Area
The European Economic Area (EEA) was established via the ''Agreement on the European Economic Area'', an international agreement which enables the extension of the European Union's single market to member states of the European Free Trade Association (EFTA). The EEA links the EU member states and three of the four EFTA states (Iceland, Liechtenstein, and Norway) into an internal market governed by the same EU laws. These rules aim to enable free movement of persons, goods, services, and capital within the European single market, including the freedom to choose residence in any country within this area. The EEA was established on 1 January 1994 upon entry into force of the EEA Agreement. The contracting parties are the EU, its member states, and Iceland, Liechtenstein, and Norway. New members of EFTA would not automatically become party to the EEA Agreement, as each EFTA State decides on its own whether it applies to be party to the EEA Agreement or not. According to Article 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Donald Mackay (scientist)
Donald Mackay (30 October 1936 – 20 October 2023) was a Scottish-born Canadian scientist and engineer specializing in environmental chemistry. Life and career Donald Mackay was born on 30 October 1936. He was a member of the faculty of Chemical Engineering and Applied Chemistry at the University of Toronto and the founding director of the Canadian Environmental Modelling Centre at Trent University. He has developed several multimedia fugacity models. He has stressed that principles of good practice also need to be adopted for chemical assessments, especially in a regulatory context. In 2004, Mackay was invested as an Officer of the Order of Canada for having "greatly contributed to the quality and our stewardship of the global environment". In 2004, he was also invested into the Order of Ontario The Order of Ontario is a civilian honour for merit in the Canadian province of Ontario. Instituted in 1986 by Lieutenant Governor of Ontario, Lieutenant Governor Lincoln Alexa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiperspirant
A deodorant is a substance applied to the body to prevent or mask body odor caused by bacterial breakdown of perspiration, for example in the armpits, groin, or feet. A subclass of deodorants, called antiperspirants, prevents sweating itself, typically by blocking sweat glands. Antiperspirants are used on a wider range of body parts, at any place where sweat would be inconvenient or unsafe, since unwanted sweating can interfere with comfort, vision, and grip (due to slipping). Other types of deodorant allow sweating but prevent bacterial action on sweat, since human sweat only has a noticeable smell when it is decomposed by bacteria. The first commercial deodorant, Mum, was introduced and patented in the late nineteenth century by an inventor in Philadelphia, Pennsylvania, Edna Murphey. The product was briefly withdrawn from the market in the US. The modern formulation of the antiperspirant was patented by Jules Montenier on January 28, 1941. This formulation was first found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
