表面活性剂对麦草同步糖化发酵转化乙醇的影响

研究了5种非离子型表面活性剂(BSA, Tween-20, Tween-80, PEG-4000, PEG-6000)促进麦草同步糖化发酵的效果. 结果表明,5种表面活性剂均能促进麦草同步糖化发酵,以Tween-20效果最为显著. 反应体系中添加Tween-20可降低酶用量而保持乙醇浓度基本相同. 在pH 5.0、温度37℃、底物浓度50 g/L及Celluclast 1.5 l用量25 FPU/g、Novozym 188用量15 IU/g的反应体系中,添加0.03 g/g Tween-20,反应72 h,乙醇浓度达到18.7 g/L,比未添加表面活性剂的体系提高了14.0%,反应时间缩短了12 h.     

苦楝素乳油配方的研究

采用HLB值法制备苦楝素乳油,确定苦楝素乙酸乙酯溶液的RHLB值为16.4;优化SDS,Tween-20和Span-60复配表面活性剂,优化表面活性剂的浓度为0.1 g/mL。所制备乳油具有良好的制剂外观、乳化性能优良、稳定性和分散性好。     

聚乙烯用高性能水基喷码油墨的研制

将马来酸酐接枝改性的氯化聚丙烯树脂(CPP-g-MAH)溶于乙酸丁酯中,再加入由Tween-20和Span-80组成的复合乳化剂进行乳化,获得了稳定的CPP-g-MAH乳液。研究了CPP-g-MAH乳液、丙烯酸复配树脂RX、乙二醇以及表面活性剂Surfynol465的用量对喷码油墨体系稳定性和墨层在聚乙烯(PE)表面附着力的影响,确定了较佳的乳化条件为:Tween-20与Span-80质量比3:2,Tween-20与Span-80的总质量为CPP-g-MAH质量的12%。较佳的水基喷码油墨配方(以质量分数表示)为:CPP-g-MAH乳液30%,水溶性丙烯酸树脂RX2%,乙二醇15%,Surfynol4651.5%。在此条件下制取的水基喷码油墨在PE表面的附着力达1.04N/mm2,非常适合于PE制品表面的喷码打印。     

复配表面活性剂水溶液吸收法处理乙酸丁酯废气

以非离子型表面活性剂为吸收剂吸收乙酸丁酯废气,研究了不同类型的Tween表面活性剂和Span-80对乙酸丁酯废气的吸收效果,并以复配表面活性剂为吸收剂分析了吸收剂温度、液气比、进塔浓度对乙酸丁酯废气吸收率的影响。结果表明,Tween-80水溶液对乙酸丁酯吸收率最高,加入Span-80后不但能够消除起泡现象还能提高乙酸丁酯吸收率,其加入量越大吸收率越大。以体积浓度3.0%的Tween-80与3.0%的Span-80复配水溶液吸收乙酸丁酯废气,在吸收剂温度为10℃,进塔废气流量为1.0 m³/h,液气比为15 L/m3/h,液气比为15 L/m³时,乙酸丁酯吸收率可达90.65%。吸收剂在解吸后循环使用,其吸收率为81.21%,且随着解吸次数的增加吸收率略有降低。     

表面活性剂对HMX基PBX性能的影响

采用溶液-水悬浮法,以F2602为黏结剂,Span-80、Tween-80、PVA、糊精为表面活性剂,制备了HMX基PBX;采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、差式扫描量热仪(DSC)对其进行了表征和热分析,并测试了其撞击感度。结果表明,加入表面活性剂包覆后未改变HMX的晶体结构;以Span-80为表面活性剂时包覆得到的HMX基PBX表面最光滑,包覆密实且无明显外漏现象;加入表面活性剂Span-80、Tween-80、PVA、糊精后得到的HMX基PBX的表观活化能分别为438.05、217.74、406.64、356.14kJ/mol,与未加表面活性剂的样品相比降低了35.52、255.83、66.93、117.43kJ/mol;加入Span-80的HMX基PBX热爆炸临界温度约上升1℃,表明对PBX的安定性无明显影响,撞击感度特性落高(H50)由44.9cm增加到63.2cm,提高了40.76%。     

复配表面活性剂水溶液吸收法处理乙酸丁酯废气

以非离子型表面活性剂为吸收剂吸收乙酸丁酯废气,研究了不同类型的Tween表面活性剂和Span-80对乙酸丁酯废气的吸收效果,并以复配表面活性剂为吸收剂分析了吸收剂温度、液气比、进塔浓度对乙酸丁酯废气吸收率的影响。结果表明,Tween-80水溶液对乙酸丁酯吸收率最高,加入Span-80后不但能够消除起泡现象还能提高乙酸丁酯吸收率,其加入量越大吸收率越大。以体积浓度3.0%的Tween-80与3.0%的Span-80复配水溶液吸收乙酸丁酯废气,在吸收剂温度为10℃,进塔废气流量为1.0 m~3/h,液气比为15 L/m~3时,乙酸丁酯吸收率可达90.65%。吸收剂在解吸后循环使用,其吸收率为81.21%,且随着解吸次数的增加吸收率略有降低。     

含铜和含锌稀溶液的吸附泡沫分离技术的研究

运用自制的泡沫分离塔,以十二烷基硫酸钠为表面活性剂对泡沫吸附分离含铜及含锌溶液的操作参数进行了研究。考察了料液浓度、pH值、气体流量、表面活性剂浓度等因素对含铜和含锌溶液泡沫分离效果的影响。结果表明：最佳操作参数为pH值5．0,料液浓度0．125mmol／L,进料流速50mL/min,气体流量100mL/min,表面活性剂浓度0．25mmol／L。同时从理论上推算出泡沫吸附分离铜离子的最佳pH值范围为5．0左右。实验还通过改变孔板的孔径大小以改变气泡的尺寸,特别研究了泡沫尺寸对泡沫吸附分离的影响。     

消泡剂共存体系中泡沫分离蛋白质

在以牛血清白蛋白(BSA)为目标蛋白、聚环氧丙烷环氧乙烷甘油醚(PGE)为消泡剂的模拟体系中,考察了表面活性剂种类(非离子型Tween-20和离子型SDBS)、浓度、溶液pH及操作参数(气体流量、初始液池高度)对BSA分离效率的影响. 结果表明,2种活性剂均能改善模拟体系的泡沫性能,使泡沫分离. 后者作用更强并能促进BSA的吸附,因DBS-通过静电作用与带相反电荷的BSA结合形成疏水性更强的BSA-DBS复合物. pH通过影响BSA的电荷分布而影响其与SDBS的结合,进而影响对BSA的吸附,初始BSA浓度0.1 g/L, PGE 4 mg/L, SDBS 50 mg/L, pH为3.4时,约66%蛋白质浓缩在泡沫液中,富集比为5.34. 增加气速或初始液池高度可得到较高收率,但富集比减小.     

表面活性剂对去血渍复合酶中蛋白酶活性的影响

研究了3种类型8种常用表面活性剂LAS,K12,AES,AOS,TX-10,6501,CAB以及AEO9对去血渍复合酶中蛋白酶活性的影响,表面活性剂浓度设定为0.2~0.8 g/L。结果表明:阴离子表面活性剂LAS,K12,AES和AOS在一般洗涤浓度0.2~0.5 g/L下对蛋白酶活性无明显影响,但在0.8 g/L的高浓度时表现出一定的抑制作用,其中LAS的抑制作用最大;非离子表面活性剂TX-10,6501和AEO9以及两性离子表面活性剂CAB在0.2~0.5 g/L浓度下的激活作用比较明显,这种激活作用随着浓度的继续增大至0.8 g/L而逐渐减弱。总体来说,阴离子表面活性剂在0.2~0.5 g/L浓度下能与去血渍复合酶中蛋白酶良好配伍,而非离子表面活性剂和两性离子表面活性剂在整个实验浓度下都能与去血渍复合酶中蛋白酶良好配伍。     

泡沫分离法提取乙醇水体系中甲基橙

采用泡沫分离法对含甲基橙的乙醇水溶液进行了提取研究. 考察了乙醇体积分数、气体流量、pH、甲基橙浓度和表面活性剂浓度对提取效果的影响,并对泡沫分离乙醇-水体系中提取中药有效成分的可行性进行了探讨. 结果表明,以十六烷基三甲基溴化铵(CTAB)为表面活性剂,在乙醇体积分数25%的乙醇-水体系中,在pH 6.0、气速80 mL/min、甲基橙浓度35 mg/L及CTAB浓度80 mg/L的操作条件下,甲基橙的富集比为14.38,回收率在98.5%以上. 在一定范围内提高表面活性剂浓度或加入稳泡剂以削弱乙醇的消泡作用,从而将泡沫分离技术应用于乙醇-水体系中中药有效成分的提取是可能的.     

复合表面活性剂微乳液法制备纳米TiO_2

以钛酸正丁酯（TNB）为原料,在较优配比5.0 g Tween-80,1.7 g司班-20,40.0 mL环己烷,8.0 mL正丁醇和2.5 mL的水的微乳体系中制备了粒径小、分散均匀的纳米TiO2微粒,用SEM、XRD对产物进行结构表征。实验结果表明：焙烧温度达到500℃时,二氧化钛出现锐钛矿晶型;随着焙烧温度的升高,晶型向金红石型转变,平均晶粒度（A101）增大,从500℃的8.86 nm增大到700℃的28.35 nm。     

Mechanism Study on the Severe Foaming of Rhamnolipid in Fermentation

Although the biosurfactant rhamnolipid has been previously characterized as having low foam ability, its fermentation is largely impeded by severe foaming. Hence, the investigation of this paradox is critically important for improving the mass production of rhamnolipid. Unexpectedly, the hydrophobic cell, instead of rhamnolipid, has been claimed to explain such severe foaming in rhamnolipid fermentation. This study tried to systematically investigate the severe foaming in fermentation, aiming to propose an effective strategy for foam control. The overflowing foam sustained a super high stability in terms of half‐time for over 30 min. The major product of rhamnolipid largely contributed to the severe foaming in the fermentation process whereas other products like cells elicited much more limited effects. Furthermore, the foam stability of the fermentation broth increased with rhamnolipid concentration and noticeably increased with agitation speed. In the classic Bikerman foam test system without stirring, rhamnolipid showed foam stability as low as Tween 20 which is well known for its poor foam stability. However, in a stirring Bikerman system, rhamnolipid exhibited a foam stability almost as high as sodium dodecyl sulfate (SDS) at 10 g/L and even surpassed SDS at a higher concentration of 20 g/L. Hence, the extraordinarily increased foam stability of rhamnolipid with both agitation and concentration could explain the severe foaming at its late‐stage fermentation when rhamnolipid‐rich solution is mechanically agitated.     

甘草美白润肤乳制备工艺的研究

用0.2 mol/L的NaOH水溶液于80℃提取甘草的有效成分,对甘草美白润肤乳生产工艺中的不同乳化时间、乳化温度以及搅拌速度等条件进行优化,用正交实验优化单硬脂酸甘油酯、Span-80和Tween-80三种乳化剂的最优配比。结果表明,甘草美白润肤乳的最佳生产工艺条件为:乳化时间50 min,乳化温度85℃和搅拌速度300 r/min;3种乳化剂配比单硬脂酸甘油酯∶Span-80∶Tween-80的摩尔比为1∶1∶1.7。本研究配制的甘草美白乳的理化指标、感官指标、卫生指标中细菌总数等均符合国家标准。     

赖氨酸脱羧酶发酵工艺及酶学性质

考察了蜂房哈夫尼菌(H.alveiAS1.1009)的L-赖氨酸脱羧酶对L-赖氨酸的脱羧作用,分析了培养基、温度、pH、激活剂等因素对酶活力的影响。实验结果表明,最适培养基成分为:ρ(蔗糖)=20 g/L、ρ(玉米浆)=20g/L、ρ(酵母膏)=5 g/L、ρ(牛肉膏)=3 g/L、ρ(蛋白胨)=10 g/L、ρ(氯化钠)=5 g/L、ρ(硫酸铵)=2 g/L、ρ(维生素B6)=5 g/L和ρ(L-赖氨酸)=5 g/L,100 mL发酵液中接种量为5 mL液体菌种。最佳转化工艺条件为:转化体系温度35℃、pH=5.0,ρ(菌体)=10 g/L,ρ(吐温-80)=0.15 g/L。L-赖氨酸脱羧酶在最适发酵和转化条件下比酶活可达7 984.43 U,底物转化率可达70%。     

Foam Fractionation of Protein with the Presence of Antifoam Agent

Foam fractionation is a promising technology for protein concentration or purification. However, the presence of an antifoam agent in fermentation broth restricted direct application of the technology. A preliminary approach of the surfactant-assisted foam process was conducted with a simulated system consisting of targeted protein bovine serum albumin (BSA), and a mixed antifoam agent (AF520, silicon oil/PGE mixture). The effects of all three classes of surfactants (anionic SDBS, cationic CTAB, and non-ionic Tween-20) on BSA foam fractionation were examined respectively. Also, the influences of solution pH, PGE, BSA, and NaCl were taken into account. The results revealed that all three classes of surfactants could stabilize foam film, so that the foam process could be operated, while the ionic surfactant exhibited excellent performance on condition that it was allowed to firmly interact with BSA to form a more hydrophobic complex, especially for cationic CTAB. When solution pH was adjusted to 7.5 and CTAB was 20 mg · mL^?1, 90% of BSA could be extracted from a previous non-foaming system containing 100 mg · mL^?1 BSA and 4 mg · mL^?1 AFA, and the enrichment reached 7.42. A higher enrichment of BSA could be obtained with increasing addition of AFA but at the expense of the recovery. On the contrary, increasing BSA concentration gave rise to an opposite performance. The experiments also showed that the foam stability of the system was substantially enhanced by NaCl, significantly lowering the enrichment.     

黄孢原毛平革菌产乙二醛氧化酶发酵条件的优化

对限氮培养基在氧环境下培养黄孢原毛平革菌(Phanerochaete chrysosporium)合成乙二醛氧化酶的条件进行了研究。结果表明:葡萄糖和酒石酸铵的组合为最佳碳、氮源组合;最佳碳源浓度为15 g/L;最佳氮源浓度为0.2 g/L;最佳接种量为3×107/50 mL;最佳通氧频率为1次/天;最佳温度为37℃。通过正交试验,确定3 mg/L维生素B1、0.05%Tween-80和5.0 mmol/L苯甲醇为最佳组合。