左建国,李维仲,翁林岽.冷冻干燥中升华界面的临界温度实验[J].农业机械学报,2010,41(10):126-128.
.of Sublimation Interface in Freeze-drying[J].Transactions of the Chinese Society for Agricultural Machinery,2010,41(10):126-128.
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冷冻干燥中升华界面的临界温度实验   [下载全文]
of Sublimation Interface in Freeze-drying   [Download Pdf][in English]
  
DOI:10.3969/j.issn.1000-1298.[year].[issue].[sequence]
中文关键词:  冷冻干燥  塌陷温度  冻干显微镜  差示扫描量热法  玻璃化转变
基金项目:
左建国  李维仲  翁林岽
大连理工大学
中文摘要:利用冻干显微镜(FDM)研究了二元水溶液冷冻干燥过程中升华界面的临界温度,采用差示扫描量热法(DSC)测量了溶液的共晶熔融温度和最大冻结浓缩溶液的玻璃化转变温度。实验结果表明,对于降温时发生共晶的溶液,临界温度为共晶熔融温度,否则将发生融化;对于降温时发生玻璃化转变的溶液,临界温度为塌陷温度,否则将发生塌陷。对于质量分数为5%蔗糖、10%葡萄糖、10%麦芽糖、10%聚乙烯吡咯烷酮(PVP)二元水溶液,微塌陷温度与塌陷温度的差值在2℃以内,微塌陷温度比玻璃化转变温度高
Key Words:
Abstract:1~3℃。Freeze-drying microscopy (FDM) was used to investigate the critical temperature (Tcr) of sublimation interface during freeze-drying of binary aqueous solutions, and differential scanning calorimetry (DSC) was used to investigate the eutectic melting temperature (Tem) and the glass transition temperature of the maximally freeze concentrated solution (T′g). The experimental results showed that if a solute crystallized from solution during freezing step, the critical temperature was the eutectic melting temperature, or else a meltback would occur. If the solute remained amorphous during the freezing process, the critical temperature was the collapse temperature, or else the amorphous phase would undergo viscous flow. For 5% Sucrose, 10% glucose, 10% maltose, 10% PVP binary aqueous solutions, the microcollapse temperature (Tmc) and the collapse temperature (Tc) differed by less than 2℃, and Tmc was 1~3℃ above T′g.

Transactions of the Chinese Society for Agriculture Machinery (CSAM), in charged of China Association for Science and Technology (CAST), sponsored by CSAM and Chinese Academy of Agricultural Mechanization Science(CAAMS), started publication in 1957. It is the earliest interdisciplinary journal in Chinese which combines agricultural and engineering. It always closely grasps the development direction of agriculture engineering disciplines and the published papers represent the highest academic level of agriculture engineering in China. Currently, nearly 8,000 papers have been already published. There are around 3,000 papers contributed to the journal each year, but only around 600 of them will be accepted. Transactions of CSAM focuses on a wide range of agricultural machinery, irrigation, electronics, robotics, agro-products engineering, biological energy, agricultural structures and environment and more. Subjects in Transactions of the CSAM have been embodied by many internationally well-known index systems, such as: EI Compendex, CA, CSA, etc.

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