【作者】 李存玉；

【导师】 彭国平；

【作者基本信息】 南京中医药大学 ， 中药化学与分析， 2013， 博士

【摘要】 超微孔过滤根据孔径的大小可以分为超滤、纳滤、反渗透,由于孔径大小的差别,超微孔技术在应用时存在多样的分离指导理论,但是均有一定的应用局限性。同一材质、孔径的滤膜,中药成分的透过率常常与现有的分离原理相违背,为了明确超微孔过滤的真实分离过程,本论文展开了超微孔过滤原理的综述和实验研究。在过滤时,溶液与滤膜接触后会出现一层非均匀分布的液-固界面层,界面层在超微孔内占据一定的膜孔体积,使得膜孔内溶液过滤的流径相对狭窄,因而提出界面层狭孔过滤的概念。根据界面狭孔效应的强弱,可以将超微孔过滤模式分为,①一级过滤模型(大孔径膜超滤)：分子筛过滤,分子大小筛分；②二级过滤模型(反渗透及小孔径纳滤)：在分子筛过滤基础上,加上界面渗透模型；③三级过滤模型(小孔径超滤或大孔径纳滤)：分子筛原理、界面狭孔、渗透与溶液混合滤过。选择三七总皂苷中分子量相似,同为三萜皂苷类成分的三七皂苷R1、人参皂苷Rgl、人参皂苷Rb1、人参皂苷Rd为实验对象,进行界面狭孔效应研究。在规范了超滤操作方法的前提下,分析在1KDa～100KDa系列孔径超滤膜中的透过规律,三七总皂苷中四种主要成分超滤透过率差异明显,三七皂苷R1和人参皂苷Rg1高于人参皂苷Rb1、人参皂苷Rd,在膜孔径达到100KDa时差异消失,这种差异并不完全是膜孔筛分引起的,主要是因为成分之间的界面效应不同,导致四种成分在界面层中的比例明显不同,从而出现差异性的透过结果。进而对三七总皂苷溶液与滤膜之间的界面层物理参数进行理论推导和计算机模拟,根据三七总皂苷在系列膜孔径中的透过率,以膜孔内过滤时溶液和界面过滤的浓度和速度方程,推导溶质过滤理论方程。以Maple16非线性拟合计算三七总皂苷的界面参数,以四种成分之间的界面层厚度差异(1.8nnm)为评价指标,并以相关系数r为指标通过Matlab R2011b验证。当流速方程中的幂值N=6时,三七皂苷R1、人参皂苷Rg1、人参皂苷Rb1、人参皂苷Rd的界面厚度(Ds)分别为2.06nm、1.96nm、3.90nm、3.87nm,趋向性常数(b)分别为1.63、1.95、0.71、0.88,在明确液-固界面参数的前提下,完善界面层浓度和流速方程,从而建立了分析溶质界面参数的界面狭孔效应计算模型。在此基础上,通过改变溶液性质,在三七总皂苷水溶液中加入有机溶剂、表面活性剂、无机盐、温度、pH值,均对溶液的表面张力、成分透过率、界面组成有影响,基本趋势为降低溶液表面张力时,成分透过率上升,且界面层中人参皂苷Rb1、人参皂苷Rd比例升高。总结相关影响因素、表面张力、成分透过行的相关性,在界面狭孔效应理论的指导下,可以通过改变液-固两相的性质,达到目的性的成分透过或截留行为。在界面狭孔效应理论的实际应用中,对中药注射剂中的超滤技术应用进行指导。冰七注射液中采用1,2-丙二醇助溶冰片降低冰片与膜之间的界面效应,提高成分透过率；通络清脑注射用粉针中改变溶液pH值,增加黄芩苷的溶解度,降低界面狭孔效应,改善成分的透过行为,同时还对膜材质的研制进行探讨,有效的提升超微孔过滤技术在中药产业中的应用。此外,不同成分在相同的液-固体系中的界面厚度和成分组成也有所差别,通过界面狭孔效应模型,完成液-固界面的组成分析。在明确成分界面狭孔效应的前提下,分析超滤时溶液实际过滤孔径R_狭,通过数学运算,当成分的透过率为60%时,供成分透过的实际膜孔半径接近0m,因此以溶质透过60%时的膜孔半径近似等于溶质的界面层厚度,即R60%≈Ds,可以根据此式,近似推算成分的界面特征参数。界面狭孔效应过滤理论的提出,并没有颠覆原有膜孔筛分的分离理论,而是对孔径筛分原理进行修正。为全面认识超微孔过滤原理及成分透过规律提供理论基础,对成分过滤反常现象进行合理化解释,并进一步指导膜分离应用的膜选择,包括选择适宜的孔径和膜材质,为膜材质研究如材质的修饰、新型膜材质的研制提供理论依据,可设计特定材质膜实现预期过滤效果,推广膜分离的应用领域,推动膜产业发展。更多还原

【Abstract】 According to membrane pore size or molecular weight cut-off (MWCO), ultramicro-porous filtration can be divided to ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO). In recent years, membrane separation processes have found wide applications in industry and research laboratories, the development of quantitative predictive models are importance for the successful application of membrane filtration. The primary difference of UF, NF and RO is membrane pore size, and the common defects of the existing models are that they do not consider the change of "meaningful membrane pore size" and therefore, cannot be compatible with each other, in part because of neglecting the interface between solution and membrane. To clarify the real filtrate progress in ultramicro-porous, this study carried out research on reviews and experiments of ultramicro-porous filtration theory.In the filtrate progress, the interface between phases is generated as two phases intersect each other, in which the molecules of two phases are permeating mutually and form a non-uniform layer the existance of interface layer caused actual membrane pores are "samller" and narrowed the solution flow path within pores. Based on the interfacial narrowed pores effect, the ultramicro-porous filtration can be divided into three filtrating model,①primary filtrated model: molecular sieving for big pore UF,②secondary filtrated model:molecular sieving and interface peanetrate for RO and small pore NF, and③) tertiary filtrated model:molecular sieving, interfacial narrowed-pores filtrate and interface peanetrate for small pores UF and big pores NF.Panax notoginseng saponins (PNS) was selected as experimental subject. Notoginsenoside Rl(Rl), Ginsenoside Rgl (Rgl), Ginsenoside Rbl (Rbl) and Ginsenoside Rd (Rd), four main components of PNS, have similar structure and molecular size, but different surface activities. Using series of membranes with different pore sizes, the transmittances of main components of PNS water solution were detected. Using the interfacial thickness difference of the four solute (1.8nm) as evaluation indexes, the values of tendency constan (b), interfacial thickness(Ds) and velocity eqution index (N) of Rl, Rgl, Rbl and Rd were calculated the by using Maple software with data of membrane radius and transmittances and were verified by Matlab R2011b which evaluated by correlation coefficients (r). Results show that Ds of main components of PNS were varied from1.96nm to3.90nm, b varied from0.71to1.95, and N was6. According to the whole method mentioned above, the fitting model of interfacial narrowed pores effect was established to analyze the interfacial characteristics for solutes.With the solution properties affected by organic solvents, surfactants, inorganic salt, tempreture and pH, the solution surface tension, solute transmittance and interfacial composition were changed correspondingly. As the surface tension decreasing, conversely the solutes tranmittance and the proportion of Rbl and Rd were increased. Therefore, under the guidance of interfacial narrowed pores effect, analyzing the relevance among of influened factors, surface tension and tranmittance to get the purposefully retain or reject results by changing the liquid-solid interfacial properties.in the practical application,1,2-propylene glycol was chosen as cosolvent to reduce the interfacial effect and improve borneol solubility and tranmittance of Bingqi injection. Moreover, the solubility and transmittance of baicalin were increased by adjusting pH to7.5, and the10KDa membrane was suitable for Tongluoqingnao powder injection with little loss of baicalin and high rejection of endotoxin.The interfacial composition and thickness of various solutes are different in the same liquid-solid system, and the start inspiring results achieved by ultramicropore will be helpful in revealing the essence of interface effect in nature.Meanwhile, the filtration theory of interface-effect did not challenge the molecular sieving theory, but instead attempt to modify it. The interfacial narrowed-pore effect may exert profound influence on the development of the whole membrane technology and provides a guideline for the application of membrane separation including selecting proper membrane pore size and material, membrane modification, designing specific membrane material and extending the fields of membrane application etc. In addition, the results develop here would be of great value to the future studies on interface by ultramicro-pore method.更多还原