• study of nanoscale structures in hydrated biomaterials using small-angle neutron scattering

    جزئیات بیشتر مقاله
    • تاریخ ارائه: 1392/01/01
    • تاریخ انتشار در تی پی بین: 1392/01/01
    • تعداد بازدید: 606
    • تعداد پرسش و پاسخ ها: 0
    • شماره تماس دبیرخانه رویداد: -
     distribution of water in three classes of biomedically relevant and degradable polymers was investigated using small-angle neutron scattering. in semicrystalline polymers, such as poly(lactic acid) and poly(glycolic acid), water was found to diffuse preferentially into the non-crystalline regions. in amorphous polymers, such as poly(d,l-lactic acid) and poly(lactic-co-glycolic acid), the scattering after 7 days of incubation was attributed to water in microvoids that form following the hydrolytic degradation of the polymer. in amorphous copolymers containing hydrophobic segments (desaminotyrosyl-tyrosine ethyl ester) and hydrophilic blocks (poly(ethylene glycol) (peg)), a sequence of distinct regimes of hydration were observed: homogeneous distribution (∼10 å length scales) at <13 wt.% peg (∼1 water per eg), clusters of hydrated domains (∼50 å radius) separated at 24 wt.% peg (1–2 water per eg), uniformly distributed hydrated domains at 41 wt.% peg (∼4 water per eg) and phase inversion at >50 wt.% peg (>6 water per eg). increasing the peg content increased the number of these domains with only a small decrease in distance between the domains. these discrete domains appeared to coalesce to form submicron droplets at ∼60 °c, above the melting temperature of crystalline peg. the significance of such observations on the evolution of micrometer-size channels that form during hydrolytic erosion is discussed.

سوال خود را در مورد این مقاله مطرح نمایید :

با انتخاب دکمه ثبت پرسش، موافقت خود را با قوانین انتشار محتوا در وبسایت تی پی بین اعلام می کنم
مقالات جدیدترین رویدادها
مقالات جدیدترین ژورنال ها