《大学化学》课程PPT教学课件（英文版讲稿）Chapter 18 Chemistry and Materials Diamond

Chapter 18 Chemistry and Materials Diamond Paper, plastic, metals, glass, ceramics

Chapter 18 Chemistry and Materials Diamond Paper, plastic, metals, glass, ceramics

18.1 Paper is made of cellulose fibers Paper was first made HARDWOOD FIBE in China as early as AD 100, of mulberry bark. and then introduced to Western SOFTWOOD FIBERS world by Arabs in eighth century. The first paper mills were built in Spain in 11th century

18.1 Paper is made of cellulose fibers • Paper was first made in China as early as AD 100, of mulberry bark, and then introduced to Western world by Arabs in eighth century. The first paper mills were built in Spain in 11th century

The use of wood to produce paper was started in USA Additives such as rosin(松香) and alum(明矾)Were added to strengthen paper and make it accept ink well Chlorine as used to bleaching paper and titanium dioxide (钛白粉) was used to make the paper white Acidic paper, acid-free paper and alkaline paper Plants alternative to trees: willow(fi), kenaf(FF). They usually have high fiber content and grow fast 70 million tons of paper are used in USA: one person 230 kilograms or six trees

• The use of wood to produce paper was started in USA. • Additives such as rosin (松香) and alum (明矾) were added to strengthen paper and make it accept ink well. Chlorine as used to bleaching paper and titanium dioxide （钛白粉）was used to make the paper white. • Acidic paper, acid-free paper and alkaline paper • Plants alternative to trees: willow (柳), kenaf (麻). They usually have high fiber content and grow fast. • 70 million tons of paper are used in USA: one person 230 kilograms or six trees

18.2 The development of plastics involved experimentation and discovery The search for Isoprene a lightweight, nonbreakable polymerization moldable polyisoprene material began With the Fig 18.5 isoprene molecules invention of react with one another to vulcanized form polyisoprene the fundamental chemical unit rubber(硫化橡 of natural rubber, which 胶) comes from rubber trees

18.2 The development of plastics involved experimentation and discovery • The search for a lightweight, nonbreakable, moldable material began with the invention of vulcanized rubber (硫化橡 胶). + + isoprene polyisoprene polymerization Fig18.5 isoprene molecules react with one another to form polyisoprene, the fundamental chemical unit of natural rubber, which comes from rubber trees

Charles goodyear discovered the rubber vulcanization in 1837 Polymer strands Fig 18.(a)when stretched the individual poly- isoprene strands in natural rubberlip past Original for Stretched with little tendency to snap back to original form one another and the rubberstays stretched. Polymerstrands (when vulcanized rubber is stretched, the Polymer strands sulfur cross-links hold the strands together, allowing the rubber to return to its original shape (b)Original form with disulfide Stretched with great tendency to cross-links snap back because of cross-links

Charles Goodyear discovered the rubber vulcanization in 1837. (a) Original form Stretched with little tendency to snap back to original form Stretched with great tendency to snap back because of cross-links (b) Original form with disulfide cross-links Fig18.6 (a) when stretched, the individual poly-isoprene strands in natural rubber slip past one another and the rubber stays stretched. (b) when vulcanized rubber is stretched, the sulfur cross-links hold the strands together, allowing the rubber to return to its original shape Polymer strands Polymer strands

Nitrocellulose and celluloid te group Fig 18.7 O一NO2 nitrocellulose also O一NO known as cellulose 人O O nitrate, is highly O combustible because NO of its many nitrate O,N NO groups, which facilitate oxidation ON Nitrocellulose(cellulose nitrate)

Nitrocellulose and celluloid Fig 18.7 nitrocellulose, also known as cellulose nitrate, is highly combustible because of its many nitrate groups, which facilitate oxidation Nitrate group Nitrocellulose (cellulose nitrate)

Bakelite and phenolic resin(酚醛树脂) OH H Formaldehyde OH CH2 OH polymerization CHA ig 18.9 the molecular network of bakelite pl shown in two dimensions Phenol-formaldehyde The actual structure resin(Bakelite) projects in all three dimensions. The first Polymers win in World War ll handset telephones were made of bakelite Synthetic rubber, radar, tank and tent Polymer and environment

Bakelite and phenolic resin (酚醛树脂) Polymers win in World War II Synthetic rubber, radar, tank and tent Polymer and environment Fig 18.9 the molecular network of bakelite shown in two dimensions. The actual structure projects in all three dimensions. The first handset telephones were made of bakelite OH CH2 CH2 CH2 OH OH CH2 CH2 OH OH CH2 CH2 OH CH2 OH CH2 OH OH C H H O OH Formaldehyde phenol polymerization Phenol-formaldehyde resin (Bakelite)

18.3 Metals come from the earth's limited supply of ores Metallic bond is responsible for the high conductivity and high gross Fig18 14 metal ions are held together by freely flowing electrons These loose electrons form a kind of electronic fluid that flows through the lattice of positively charged ions

18.3 Metals come from the Earth’s limited supply of ores Metallic bond is responsible for the high conductivity and high gross. Fig18.14 metal ions are held together by freely flowing electrons. These loose electrons form a kind of “electronic fluid” that flows through the lattice of positively charged ions

The form in which a metal is most likely to be found in nature is a function of its position in periodic table Sulfides Uncombined Chlorides Other compot 17 see caption A 5A Oxides Mg 3 6 91011 Ca Sc Ti v Cr Mn Fe Co Ni Cu Zn Ga CdIn Hf Ta Fig 18 19 which compound of a metal is most prevalent in nature is related to the metals position in the periodic table

The form in which a metal is most likely to be found in nature is a function of its position in periodic table. Fig 18.19 which compound of a metal is most prevalent in nature is related to the metals position in the periodic table

Metal-containing compounds can be converted to metals Cathode M Transforming the metal containing compound to a metal is less energy Sheets of Anode sludg Sheets of intensive Imp Solution oure Transforming the metal- copper containing CUSO4 copper containing compound to a metal is more energy Fig 18.21 high-purity copper is recovered by intensive electrolysis. Pure copper metal deposits on the negative electrode as copper ions in solution gain electrons. The source of these copper ions is a positively charged electrode made of Impure copper

Metal-containing compounds can be converted to metals Sheets of impure copper Sheets of pure copper Solution containing CuSO4 Transforming the metal￾containing compound to a metal is less energy intensive Transforming the metal￾containing compound to a metal is more energy intensive Fig 18.21 high-purity copper is recovered by electrolysis. Pure copper metal deposits on the negative electrode as copper ions in solution gain electrons. The source of these copper ions is a positively charged electrode made of impure copper