با سلام خدمت کاربران در صورتی که با خطای سیستم پرداخت بانکی مواجه شدید از طریق کارت به کارت (6037997535328901 بانک ملی ناصر خنجری ) مقاله خود را دریافت کنید (تا مشکل رفع گردد).
ردیف | عنوان | نوع |
---|---|---|
1 |
Scaling laws of entangled polysaccharides
مقیاس بندی قوانین پلی ساکاریدهای گرفتار-2020 We study the dilute solution properties and entangled dynamics of hydroxypropyl cellulose (HPC), a semiflexible
polymer, in aqueous solution. Intrinsic viscosity data are consistent with a polymer in θ solvent with a Kuhn
length ≃22 nm. The overlap concentration, estimated as the reciprocal of the intrinsic viscosity scales with the
degree of polymerisation as c* ∝ N−0.9. We evaluate different methods for estimating the entanglement crossover,
following the de Gennes scaling and hydrodynamic scaling models, and show that these lead to similar
results. Above the entanglement concentration, the specific viscosity, longest relaxation time and plateau
modulus scale as ηsp ≃ N3.9c4.2, τ ≃ N3.9c2.4 and GP ≃ N0c1.9. A comparison with other polymers suggests that the
rheological properties displayed by HPC are common to many polysaccharide systems of varying backbone
composition, stiffness and solvent quality, as long as the effect of hyper-entanglements can be neglected. On the
other hand, the observed scaling laws differ appreciably from those of synthetic flexible polymers in good or θ-
solvent. Keywords: Polysaccharide | Cellulose | Viscosity | Rheology | Entanglement | LCST | Hydroxypropyl cellulose | Scaling | Kuhn length | Rouse mode |
مقاله انگلیسی |