The Reversed-Phase HPLC of Dispersing Agent NNO And Determination of Molecular Weight Distributions

The dispersing agent NNO(condensates of β - naphthalenesulphonic acid and formaldehyde) were analyzed by reversed-phase HPLC. The analytical conditions were: column ODS, 2 × 250mm; flow rate, 5ml/ min; sample size, 2μl(20% NNO aqueous solution); UV detector, λ = 254nm; column temperature 293k

It is shown that the new method is very efficient, the analysis time being only 11 minutes. We found eight component compound peaks of the condensates. The peaks of the highly condensed compounds could also be separated and identified by IR spectrum. The weight distribution curve of seven samples are given.     

MINOR SURFACE-ACTIVE LIPIDS OF OLIVE OIL AND VISCOELASTICITY OF PROTEIN FILMS AT THE OLIVE OIL-WATER INTERFACE

The influence of the minor surface-active lipids of olive oil on the viscoelastic parameters of bovine serum albumin, sodium caseinate and egg yolk films, formed following adsorption at the olive oil-protein solution interface, was studied. All the parameters substantialy decreased in the case of bovine serum albumin when surface-active lipids were removed from the olive oil while the absence of these components resulted in purely viscous films in the cases of sodium caseinate and egg yolk. Protein film viscoelasticity is probably influenced by olive oil surface-active lipids as a result of their interactions with adsorbed and unfolded protein molecules at the oil-protein solution interface.     

聚丙烯酸钠在Al2O3/水界面吸附行为的ESR研究

采用电子自旋共振技术结合自旋标记方法研究了聚丙烯酸钠在Al2O3／水界面吸附的分子构型和运动行为。结果表明，哌啶氮氧自由基在聚丙烯酸钠分子上是链间标记，它的运动受到聚合物长链的束缚；聚丙烯酸钠在Al2O3上的吸附等温线呈Langmuir型，随表面吸附量的增加，吸附在Al2O3上的聚丙烯酸钠分子的固着链节分数减小，从平衡浓度0.25mg/ml时的0．90变化到饱和吸附时的0．65。聚丙烯酸负离子通过静电引力多点吸附在Al2O3表面，分子中的大部分链节平躺在Al2O3表面，少部分链节伸向溶液。