Polyvinylpyrrolidone (PVP), a Molecular Weight Determination with the BI-MwAGydF4y2Ba
PolyvinylpyrrolidoneGydF4y2Ba(PVP) is a polar molecule and is employed in a broad range of applications. For instance, as it easily passes through humans, it is used as a binding agent in pharmaceutical tablets. As PVP binds to polar molecules reasonably well, it is additionally employed as a paper coating. PVP is also present in toothpaste, paint shampoo and adhesives.GydF4y2Ba
快速，可靠的特征对于更好地理解制造执行，处理和结构 - 托管关系至关重要。With the appropriate selection of instruments, the determination of molecular weight of PVP is simple.GydF4y2Ba
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在水中，在Aldrich中发现的PVP溶解了I，并收集了数据GydF4y2BaBI-MwAGydF4y2Ba在批处理模式下。光散射中的一个实质性问题是灰尘，BI-MWA设计通过密封流系统和自动粉尘消除算法为答案提供了答案。这些元素消除了灰尘的有害影响。GydF4y2Ba
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Employing the BI-MwA software, values for Kc/∆R were automatically calculated. Here, K is the Debye constant and it is proportional to the square of the refractive index increment, dn/dc. A value of 0.174 mL/g is employed for dn/dc. c is polymer concentration and ∆R is relative to the surplus scattered strength.GydF4y2Ba
为了建立分子量，该软件随后产生Zimm，Berry或Debye图和分子量的值，回旋半径（除Debye图中除外）和第二个病毒系数。推断到零角度和零浓度后，量KC/∆R与重量平均分子量的倒数相同（MGydF4y2BawGydF4y2Ba）。他们GydF4y2BawGydF4y2Baestablished by fitting is (5.490 +/- 0.030) x 10GydF4y2Ba4GydF4y2Bag/mol.GydF4y2Ba
18.1 nm是回旋的半径（rGydF4y2BaGGydF4y2Ba) determined by fitting. This radius of gyration is notably bigger than is usually expected from such a small molecular weight polymer. Usually, random coil polymers with a molecular weight under 75,000 g/mol are Rayleigh scatterers as their RGydF4y2BaGGydF4y2Bais lower than 12 nm. The value of RGydF4y2BaGGydF4y2Baestablished by light scattering is known as the average, an average weighted by the square of molecular weight. The high value of RGydF4y2BaGGydF4y2Bacan be explained by the fact that the PVP sample is polydisperse.GydF4y2Ba
The next virial coefficient (AGydF4y2Ba2GydF4y2Ba）通过配件获得的是4.33 x 10GydF4y2Ba-4GydF4y2Ba厘米GydF4y2Ba3GydF4y2Bamol/gGydF4y2Ba2GydF4y2Ba。As this value is positive, it suggests that water is a good thermodynamical solvent for PVP.For contrast, the second virial coefficient of molecular weight 55,000 g/mol PS in THF is 7 x 10 -4cmGydF4y2Ba3GydF4y2Bamol/gGydF4y2Ba2GydF4y2Ba。GydF4y2Ba
This data displays that theGydF4y2BaBI-MwAGydF4y2Bacan be employed to establish the molecular weight of PVP.GydF4y2Ba
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This information has been sourced, reviewed and adapted from 欧洲杯足球竞彩materials provided by Brookhaven Instrument Corporation.GydF4y2Ba
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