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[求助]
静态光散射
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| 静态光散射中的dn/dc,怎样测啊，是用阿贝折光仪测定吗 |
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【答案】应助回帖
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感谢参与，应助指数 +1
jiwei221428: 金币+1 2013-07-16 10:07:57
感谢参与，应助指数 +1
jiwei221428: 金币+1 2013-07-16 10:07:57
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建议你看此贴http://muchong.com/html/201211/5144858.html (dn/dc)可以在polymer handbook上查到（对于常见高分子，如果只要实验中估算，水溶液可以用0.15，THF溶液可以用0.12），或用SLS配套的折射率计测量 |
2楼2013-07-15 21:11:33
【答案】应助回帖
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感谢参与，应助指数 +1
jiwei221428: 金币+1 2013-07-16 10:08:02
感谢参与，应助指数 +1
jiwei221428: 金币+1 2013-07-16 10:08:02
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折光指数增量dn/dc不仅和溶剂有关还与具体的聚合物有关，同时还与聚合物的分子量以及测量条件如温度等等有关，有条件的情况下，建议还是自己测一下。有专门的dn/dc测量仪，其实就是一个示差检测器，所以用GPC上的示差检测器也可以测量dn/dc的值。 dn/dc实际上是表征聚合物在溶液中的衬度的，原则上用阿贝折光仪是可以测量的，通过阿贝折光仪测出不同浓度的折光指数然后plot就得到了dn/dc，当然那只是原则上，实际上没有可操作性，因为聚合物在溶液中的折光指数增量实在太小了，阿贝折光仪虽然能够显示到小数点后第三位（第四位估读），但仍然达不到精度要求，所以用阿贝折光仪是测量不出dn/dc数值的。 |
3楼2013-07-15 21:53:29
【答案】应助回帖
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jiwei221428: 金币+3 2013-07-16 10:07:40
jiwei221428: 金币+3 2013-07-16 10:07:40
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本来想上传一些常见的给你参考的，貌似变态的论坛回复不能通过普通方式上传文件了，烦，粘帖给你吧。 SPECIFIC REFRACTIVE INDEX INCREMENTS Values taken from LDC Milton Roy Technical Note All measurements performed at 23°C unless otherwise specified. Wavelength=633nm SAMPLE dn/dc (ml/gm) Cellulose tricarbanilate Tetrahydrofuran, W = 1.39x106 0.163 -Chymotrypsinogen Aq. 0.15M NaCl, 0.1M phosphate buffer, pH 7.2 W = 2.59x104 0.1708 Deoxyribonucleic acid (calf thymus) Aq. 0.1M tris buffer, pH 8.4, W = 26.4x106 0.166 Dextran Water, W = 6.82x104 0.147 Dodecylammonium chloride Aq. 1N NaCl 0.127 Gelatin Aq. 0.1N NaCl, W = 1.98x105 0.163 Heparin Aq. 0.3N NaCl 0.1290 Hydroxyethyl starch Aq. 0.05N NaCl, W = 5.6x104 - 5.6x105 0.1354 Mucopolysaccharides Aq. 0.1% NaCl, W = 7.2x103 - 3.2x104 0.1100 Polyacrylamide Water, W = 5.5x106 0.142 Poly (acrylamide/sodium acrylate) (70/30 mole) Aq. 1N NaNO3, W ~ 106 0.165 Polyacrylate, sodium salt Aq. 0.1N NaCl, W = 6.12x106 - 9.29x106 0.175 Polyacrylic acid Tetrahydrofuran, W = 5.57x103 0.0738 Tetrahydrofuran, W = 7.2x103 0.0994 Poly (acrylonitrile/styrene) (28.5/71.5 wt) Tetrahydrofuran, W = 3.83x104 0.1546 Polyamides: Unspecified composition, tetrahydrofuran W = 2.49x103 - 6.76x105 0.106 Unspecified composition, N, N'- dimethylformamide W = 52.8x103 - 59.4x103 0.1747 Unspecified composition, formic acid W = 2x104 - 1x105 0.1350 “Nylon”, hexafluoroisopropanol W = 2300 - 1800 0.253 Polyamines (quarternary ammonium salt) Aq. 0.4N NaCl 0.149 Aq. 1N NaCl 0.133 Aq. 2N NaCl 0.080 Polycarbonates: Unspecified composition, methylene chloride W = 3.0x104 0.1582 Unspecified composition, tetrahydrofuran W = 3.38x104 0.177 Polyesters: Unspecified composition, chloroform, W = 1.72x104 0.1133 Unspecified composition, chloroform, W = 4.4x103 0.1250 Phthalic acid/propylene oxide/maleic acid (1/2/1 mole), Tetrahydrofuran, W = 104 0.117 Polyethylene Trichlorobenzene, W = 5.46x104 - 2.21x105, 135°C -0.097 o-dichlorobenzene, W = 5.46x104, 135°C -0.056 -chloronapthalene, 145°C -0.177 Polyglycol, unspecified composition Tetrahydrofuran, W = 500 - 3x103 0.055 Polysobutylene Tetrahydrofuran, W = 3300 0.0974 Tetrahydrofuran, W = 6100 0.1026 Polymethyl methacrylate Tetrahydrofuran, W = 6.06x104 0.083 Poly(methyl methacrylate/butyl methacrylate) (60/40 mole), tetrahydrofuran, W = 6.29x104 0.082 Polyolefin sulfones: Unspecified composition, tetrahydrofuran, W = 9.18x105 0.1132 Unspecified composition, chloroform, W = 1.95x105 0.101 Unspecified composition, chloroform, W = 5.64x105 0.082 Poly(phenol/formaldehyde), unspecified composition Tetrahydrofuran , W = 4.3x104 0.1211 Polyphenolic acid, unspecified composition Aq. base, W = 4.2x106 0.0854 Polypropylene 1,2,4 trichlorobenzene, W = 3.66x105, 145°C -0.091 Polystyrene N,N' - dimethylformamide, W = 1.76x105 0.159 Tetrahydrofuran, W = 960 0.1680 Tetrahydrofuran, W = 2.4x103 0.1768 Tetrahydrofuran, W = 4.3x103 0.1828 Tetrahydrofuran, W = 2.59x105 0.1845 Toluene, W = 1.78x105 - 2.59x105 0.110 Poly(styrene/allyl alcohol) (50/50 mole) Tetrahydrofuran, W = 4.2x103 0.172 Poly(styrene/maleic acid), unspecified composition Aq. 0.1N NaCl 0.170 Polyvinyl acetate Ethyl acetate, W = 3.73x105 0.077 Poly(vinyl acetate/ethylene) (85/15 mole or wt., uncertain) Ethyl acetate 0.087 Polyvinyl chloride Tetrahydrofuran, W = 8.35x104 - 1x105 0.101 Polyvinyl chloride Cyclohexanone, W = 1.73x105 - 2.21x105 0.0650 Polyvinylpyrrolidone, unspecified composition N, N' - dimethylformamide 0.095 All measurements performed at 26°C unless otherwise specified. Dextran Aq. 0.05M KH2PO4, pH 7.0 W = 62,500, 23°C 0.1368 Epoxy Resin Unspecified composition, tetrahydrofuran W = 12,600 0.1871 Unspecified composition, tetrahydrofuran W = 42,700 0.1869 Unspecified composition, tetrahydrofuran W = 51,700 0.1884 Unspecified composition, tetrahydrofuran W = 63,600 0.1851 Ethylene oxide/Lignite (25/1 mole) Water, W = 1.49x106, 25°C 0.1360 Lignin sulfonate, sodium salt Aq. 0.1M NaNO3, pH 6.6 W = 49,600 0.1875 Aq. 0.5M NaNO3, pH ~ 5.5 W = 44,400 0.1839 Phenoxy Resin Unspecified composition, tetrahydrofuran W = 51,700, 23°C 0.1773 Polyacrylamide Water, W = 3.69x106, 25°C 0.1829 Aq. 1M NaCl, W = 7.72x106, 25°C 0.1587 Aq. 1M NaCl, W = 8.00x106, 25°C 0.1556 Polyacrylate, cationic salt Unspecified composition, water W = 28,200, 25°C 0.1463 Polyacrylic acid Aq. 0.05M sodium acetate, pH 7.0 W = 9430 0.1501 Polyamide Unspecified composition, dimethyl sulfoxide W ~ 30,000, 23°C 0.1054 Unspecified composition, dimethyl sulfoxide W ~ 160,000, 23°C 0.0822 Polybutadiene Tetrahydrofuran, W = 6160 0.1295 Polycarbonate Unspecified composition, chloroform, 23°C 0.1445 Unspecified composition, tetrahydrofuran W = 22,400, 23°C 0.1855 Polychloroprene Tetrahydrofuran, W = 378,000, 23°C 0.1274 Polydimethylsiloxane Toluene, W = 19,000 -0.0913 Toluene, W = 571,000 -0.0948 Poly ethylene/Propylene oxide Unspecified composition, methanol W = 4000, 23°C 0.1341 Unspecified composition, methanol W = 4500, 23°C 0.1290 Unspecified composition, methanol W = 4540, 23°C 0.1346 Poly (methyl methacrylate) Tetrahydrofuran, W ~ 100,000, 23°C Sample A 0.0800 Sample B 0.0816 Sample C 0.0909 Polypropylene oxide Chloroform, 23°C 0.1545 Polystyrene Methyl ethyl ketone, W = 3900, 23°C 0.2067 Methyl ethyl ketone, W = 259,000, 23°C 0.2120 Polyurethane Unspecified composition, tetrahydrofuran W = 35,500, 23°C 0.1417 Unspecified composition, tetrahydrofuran W = 46,200, 23°C 0.1523 Unspecified composition, tetrahydrofuran W = 63,100, 23°C 0.1477 Unspecified composition, tetrahydrofuran W = 72,400, 23°C 0.1469 Polyvinylacetate Tetrahydrofuran, W = 4.66x106 0.0471 Tetrahydrofuran, W = 107,000 0.0502 Polyvinyl alcohol Aq. 0.1M KH2PO4, pH 7.0 W = 29,600 0.1534 Aq. 0.2M NaNO3 0.5% Carbowax (PEG 1500), W = 104,000 0.1645 Vinyl benzyl chloride/Dichlorobutadiene (97/3 wt) o-xylene, W = 2.17x107, 35°C 0.0416 Vinyl chloride/Vinylidene chloride Unspecified composition, tetrahydrofuran W ~ 100,000 0.1187 |
4楼2013-07-15 21:55:56