双重Pickering乳液法制备聚丙烯酰胺多孔微球及应用

采用亲水性气相二氧化硅N20和疏水性气相二氧化硅H30复配表面活性剂制备O/W/O型双重乳液,以此为模板,聚合中间相,挥发内相制备聚丙烯酰胺（PAM）多孔微球,并用于染料分子亚甲基蓝的吸附。结果表明：乳液显微镜照片显示水油比对双重乳液的形成有很大的影响,当水油比(O₁/W)/O₂为(1/2)/2时,可得到稳定的双重乳液;扫描电镜（SEM）照片显示PAM多孔微球基本呈球形,但粒径不均匀,球体表面粗糙,内部为空心结构;激光粒度仪（DLS）结果表明PAM微球平均粒径为356nm,多分散系数（PDI）为0.718,比表面积为230m²/g,粒径分布宽;在吸附温度35℃、吸附时间5min时对亚甲基蓝的吸附率为98.89%,最大吸附率超过99%,在吸附速率和吸附率上均优于传统PAM吸附剂,本研究为染料废水的处理提供了新方法。     

O/W型微乳液的制备及稳定性的研究

以Span80和Tween20作为复合表面活性剂,环己烷作为油相,采用滴加法在高速剪切作用下制备了性能稳定的O/W型微乳液。分别研究了Span80/Tween20质量比、Span80/Tween20用量、水滴加量、环己烷用量、乳化温度等因素对微乳液平均粒径的影响。当Span80/Tween20质量比为1∶1,Span80/Tween20用量16g,水滴加量30g,乳化温度30℃,环己烷用量5g时,制备的微乳液平均粒径最小(为50.15nm),且分布均匀。其稳定性研究结果表明:微乳液经过10000r/min高速离心能保持很好的稳定性,放置60d后,10000r/min高速离心依然稳定存在。     

纳米聚合物微球的制备及其应用性能评价

本文以丙烯酰胺(AM)单体水溶液为分散相,Span80/Tween80为乳化剂,白油为分散介质,配制了稳定的丙烯酰胺微乳液。依据HLB值和最大增溶水相量原则,配制了油相质量分数为45.0%、Span80/Tween80(质量比3∶1)复合乳化剂质量分数为19.5%、水相质量分数为35.5%的W/O微乳液(以体系总质量计),40℃下利用反相微乳液聚合法反应2h,制备了纳米交联聚丙烯酰胺微球。结合转化率的计算,探讨了聚合反应温度、反应时间、引发剂用量及交联剂用量等合成条件对交联PAM微球转化率的影响,确定了具有较高转化率的交联PAM微球的优化合成条件:交联剂(N,N-亚甲基双丙烯酰胺)MBA用量为0.10%、引发剂(APS/SHS)用量为0.50%(以单体质量计)。采用扫描电子显微镜(SEM)和偏光显微镜对PAM微球的形貌进行了表征。SEM和偏光显微镜结果显示,微球具有较规则的球型,粒径分布较为均一,约为50～100 nm。对微球的应用性能进行了评价,结果显示,PAM微球具有较高的固形物含量以及较大的吸水膨胀倍率。填砂管封堵实验表明,聚合物微球对提高采收率具有较为明显的作用。     

乳液交联法制备多孔淀粉及其吸附性能

以可溶性淀粉为原料,用环己烷为油相的油包水乳液,通过交联反应成功制备了多孔淀粉。通过实验,优化了环己烷的加入量。扫描电镜显示多孔淀粉的表面有大量微孔;红外光谱扫描表明交联成功,并且大量羟基仍然存在;X射线衍射光谱分析结晶度大大降低。多孔淀粉的比表面积为3.456m2/g,吸油率高达162%,对亚甲基蓝的最大饱和吸附量是145mg/g;相比酶解法制备的多孔淀粉,本文提出的乳液交联法制备的多孔淀粉的比表面积提高了1.6倍,吸油率提高了0.7倍,对亚甲基蓝的最大饱和吸附量提高了近4倍。多孔淀粉通过氢键作用吸附染料亚甲基蓝和碱性品红,且是一个快速平衡的过程。     

聚丙烯酰胺/聚氨酯水凝胶的制备及其对Pb~(2+)吸附的研究

以聚丙烯酰胺(PAM),聚氨酯(PU)为制备凝胶的基本单元,通过在室温下将线性PAM溶解和分散在水中,添加PU组分,制备出一种合成简便的聚丙烯酰胺/聚氨酯(PAM/PU)水凝胶,并研究了其对Pb~(2+)的吸附性能,探索了吸附的最佳组分,结果表明凝胶在15%(wt)PAM,40 g/L PU吸附效果最好,PAM分子量对凝胶的吸附性能影响较小。     

反相乳液法制备淀粉基微球及其表征

以可溶性淀粉为原料,N,N-亚甲基双丙烯酰胺(MMBA)或环氧氯丙烷(ECH)为交联剂,Span60和Tween60混合为乳化剂,环己烷(80mL)和三氯甲烷(20mL)为油相,采用反相乳液法制备淀粉微球(starch microspheres)。以控制变量法来改变不同物质用量,通过扫描电镜观察微球形貌变化,确定最优的条件:淀粉浓度10%,乳化剂用量0.8g,油水比例3∶1,交联剂选用环氧氯丙烷(4mL)制备淀粉微球。利用红外光谱,扫描电镜,比表面积及孔径分析仪对淀粉微球进行性能表征,为以后应用研究作铺垫。     

水醇淀粉凝胶的形成及多孔淀粉的制备

以木薯淀粉为原料，水和乙醇为混合介质，利用溶胶-凝胶法及超临界CO₂干燥制备多孔淀粉，分别考察了水醇比、糊化时间、固含量、冷藏时间、乙醇置换用量、置换时间等对凝胶体积收缩率和质量损失率的影响，通过扫描电子显微镜、比表面积及孔径分布测试仪、X射线衍射仪表征了多孔淀粉形貌及孔结构，并考察了多孔淀粉的吸油性能。结果发现，水醇比为19∶1，固含量为13%，糊化时间为30min，冷藏时间为5天，醇置换量为5mL/g，置换时间为30min，水醇凝胶的体积收缩程度和质量损失相对较小，多孔淀粉的比表面积为122m²/g，平均孔径为25.6nm，大豆油的吸附率可达457%（质量比）。研究结果表明，适当调整固含量，能改善凝胶的三维网孔密度，增大多孔淀粉的比表面积及孔容；水醇淀粉凝胶中的淀粉分子能形成一定结晶结构的网络骨架，利于维持水醇凝胶的骨架稳定性。     

EVA38/Tween20凝胶气体分离膜的制备及其性能

采用溶剂挥发法制备了EVA38/Tween20凝胶膜,研究了不同Tween20含量对凝胶膜物理化学结构和气体渗透性能的影响。结果表明,Tween20与EVA38具有良好的相容性。Tween20的引入降低了膜的结晶度和熔融温度,也明显改善了膜的柔顺性,因而膜的CO2和N2渗透系数显著增加。同时膜的CO2/N2选择性也增加,这可以归因于Tween20中的乙氧基团对CO2强的选择吸附作用。当Tween20添加量从0增加到100%（以EVA38质量为基准）时,凝胶膜的CO2渗透系数由EVA38膜的89.5 Barrer增加到285 Barrer,CO2/N2理想分离因子从14.92增加到19.13。     

海藻酸辅助制备氧化铝小球的乳液扩孔研究

前期开发的海藻酸辅助法制备氧化铝小球,具有颗粒在水中成型、能耗低与生产过程绿色无污染等特点。在此基础上,结合广泛应用于介孔及大孔材料制备上的乳液模板法,对γ-Al2O3小球进行扩孔,制备了总孔容及平均孔径较大的球形γ-Al2O3,以氮吸附-脱附、机械强度测定仪、XRD、SEM、TG等方法对样品进行表征,考察了乳液类型、乳液用量对γ-Al2O3小球孔结构及其他理化性质的影响。结果表明:乳液质量分数为10%(以PB质量为100%)时,所制备的γ-Al2O3小球的总孔容可达0.7 cm3/g左右,平均孔径可达10 nm左右,孔径分布较集中;少量乳液的添加不会影响γ-Al2O3小球的晶相,此外,在高温煅烧过程中,所添加乳液较易充分燃烧,因此不会引入积炭问题。     

正交实验优化PAM水凝胶水解工艺

用溶液聚合法制备了交联型聚丙烯酰胺水凝胶(PAM),对影响聚丙烯酰胺水凝胶水解的因素进行了研究。以饱和溶胀率为指标,采用正交设计的方法对水解温度、水解度、水解时间等因素进行了研究,通过实验,确定了聚丙烯酰胺最佳的水解工艺条件为:水解温度:80℃;水解度:70%;水解时间:6 h;乙醇∶水(体积)=1∶1。此时,水凝胶的饱和溶胀率可以高达707 g/g。     

Porous polymers prepared via high internal phase emulsion polymerization for reversible CO2 capture

A series of porous polymers with different pore volumes, pore sizes, and crosslinking densities were synthesized by high internal phase emulsion (HIPE) polymerization. The crosslinked polymerized HIPEs (polyHIPEs) were formed by the copolymerization of 4-vinylbenzyl chloride and divinylbenzene using water droplets in conventional or Pickering HIPEs as the templates. These porous materials were further modified by quaternization and ion exchange to introduce quaternary ammonium hydroxide groups. The resulting polyHIPEs were utilized as sorbents for reversible CO₂ capture from air using the humidity swing. The effect of pore structure on the CO₂ adsorption and desorption processes was studied. The polyHIPEs containing large pores and interconnected porous structures showed improved swing sizes and faster adsorption/desorption kinetics of CO₂ compared to a commercial Excellion membrane with similar functional groups.     

Preparation of acrylamide‐based poly‐HIPEs with enhanced mechanical strength using PVDBM‐b‐PEG‐emulsified CO2‐in‐water emulsions

Poly(vinyl acetate‐alt‐dibutyl maleate)‐block‐poly(ethylene glycol) (PVDBM‐b‐PEG) copolymers were synthesized via reversible addition–fragmentation chain transfer radical polymerization and used as emulsifiers to form stable CO₂‐in‐water high internal phase emulsions (C/W HIPEs). Then, highly interconnected cellular polyacrylamide (PAM) and poly(acrylamide‐co‐N‐hydroxymethyl acrylamide) [P(AM‐co‐HMAM)] poly‐HIPEs with enhanced mechanical strength were prepared based on the stable C/W HIPEs. The porous structures of the PAM poly‐HIPEs, as well as morphology and compressive modulus, could be influenced by the surfactant concentration and the length of the CO₂‐philic tails of the surfactants. PAM poly‐HIPEs with the smallest average pore diameter (11.12 ± 0.62 μm) and the highest compressive modulus (22.65 ± 0.10 MPa) could be obtained by using the short CO₂‐philic chains of the PVDBM‐b‐PEG surfactant at a high concentration (1.0 wt %). Moreover, with the copolymerization of N‐hydroxymethyl acrylamide (HMAM) comonomers with acrylamide, the compressive modulus of the obtained P(AM‐co‐HMAM) poly‐HIPEs was three times higher than that of PAM poly‐HIPEs. Both PAM and P(AM‐co‐HMAM) poly‐HIPEs were employed as scaffolds to guide H9c2 cardiac muscle cellular growth. Fluorescence images showed that a smaller average pore size and a narrower pore‐size distribution were helpful for cell growth and proliferation on these materials. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46346.     

Adsorption and recognition of protein molecular imprinted calcium alginate/polyacrylamide hydrogel film with good regeneration performance and high toughness

Protein imprinted calcium alginate/polyacrylamide hydrogel film (CA/PAM MIP) with high toughness was prepared using bovine serum albumin (BSA) as template molecule, sodium alginate and acrylamide as functional monomers, N,N′-methylenebisacrylamide (MBAA) as the covalent cross-linker and CaCl₂ as the ionic cross-linker via UV radiation-reduced polymerization. Factors affecting the adsorption capacity and imprinting efficiency of the BSA-imprinted CA/PAM hydrogel films were investigated, such as ratio of polyacrylamide/sodium alginate, film thickness, MBAA concentration and CaCl₂ concentration. Results showed that the CA/PAM MIP exhibited an obvious improvement in terms of adsorption capacity for BSA compared with non-imprinted polymer (NIP). The adsorption capacity of MIP for BSA reached 22.49 mg/g, which was 2.7 times higher than NIP. The regeneration property of the BSA-imprinted CA/PAM hydrogel was distinctly improved and the imprinting efficiency of CA/PAM MIP maintained 77.95% of the initial value after five repetitions. Single and binary proteins rebinding indicated that the CA/PAM MIP exhibited good recognition performance. Cell culture experiments showed CA/PAM MIP was more suitable for cell culture than CA/PAM NIP. The residual sodium dodecyl sulfate (SDS) in the elution process leaded to the death of mouse fibroblast cells (L929) after 3 days. A moderate elution solution without residue eluent should be used to prepare MIP for cell culture.     

Preparation and Characterization of Imprinted Porous Materials with High Selectivity for Luteolin

In order to selectively separate luteolin from its crude solution, we synthesized imprinted porous materials with high recognition specificity for luteolin, using an imprinting technique. Modified luteolin was used as template, vinyltriethoxysilane as the functional monomer, and tetraethyl orthosilicate (TEOS) as the cross‐linking agent. The results showed the following optimum reaction conditions: The reaction ratio between luteolin and acryloyl chloride was 1 : 2 (0.10 g/0.20 g), adding 1.0 g precursor; the feasible elution time was 12 h; when the molar quantity of modified template molecule was 0.01 mol and ethenyltriethyloxy‐silane (VTEO) was 0.04 mol, the maximum yield reached 91.6 %. All samples were tested by Brunauer‐Emmett‐Teller method, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy, equilibrium adsorption experiments and selective adsorption experiments. It was found that the imprinted porous materials showed excellent selectivity for luteolin in aqueous solution. Characterization by FTIR suggested that an addition reaction had occurred between the modified template molecule and VTEO while forming ester bonds in the functional precursor. Results from pore structure analysis indicated that the imprinted porous materials had good channels, and the average pore size of the prepared porous materials was between 35.85 and 95.82 Å. Adsorption dynamics analysis suggested that, when the adsorption time reached 3 h, the adsorption process had reached balance and the adsorption capacity was at steady state. These porous materials had highly selective recognition properties and high equilibrium adsorption capacity for the template molecule. The equilibrium adsorption capacity of the imprinted porous materials to the template molecule was 11.4 times that of the blank porous materials.     

高内相乳液模板法合成有机硅聚苯乙烯多孔材料及应用

以四乙烯基四甲基环四硅氧烷、苯乙烯、二乙烯基苯为连续相,采用高内相乳液模板法制备了有机硅聚苯乙烯多孔吸附材料。用FT-IR、SEM、UV-VIS对材料进行表征,研究了其表面形态及其对有机染料罗丹明B水溶液的脱色效果。结果表明:多孔材料为互通大孔材料,材料中存在两级孔结构",泡孔"与"毛孔",泡孔尺寸约10μm,毛孔尺寸约2μm。当吸附时间为20h时,对罗丹明B水溶液脱色效果最佳,且脱色效果随多孔材料投入量、罗丹明B初始浓度的增大而增大。     

软模板法用壳聚糖制备富氮多孔碳材料

以壳聚糖溶液为原料、三嵌段两亲共聚物F127为软模板,采用一步法合成多孔碳氮材料,考察了复配溶液pH值及碳化温度等条件对材料孔结构、比表面积和吸附CO2的影响. 结果表明,材料以介孔为主,比表面积最高达457 cm2/g,氮含量最高达7.60%,表面氮元素含量最高达8.45%,以吡啶类活泼价态形式存在,材料对CO2的吸附量最高达80.8 mg/g,吸附效率达0.274 mg/cm3.     

中孔炭材料的制备及吸附性能的研究

以正硅酸乙酯为模板硅源，酚醛树脂为炭前驱体，运用模板法制备了中孔炭材料。并用红外光谱（FT—IR）、扫描电镜（SEM）、低温N2自动吸附、甲醛和VB12饱和吸附等对样品形貌、孔结构和吸附性能进行了研究。结果表明：制备的炭材料孔径集中分布在2-7nm左右，且中孔孔隙率达到74．6％，比表面积达到1012m^2／g；材料对VB12大分子有较好的吸附性能。表明通过控制正硅酸乙酯的水解条件能制备孔径集中的中孔炭材料。     

超声波、牛血清蛋白和吐温试剂辅助玉米秸秆酶水解

研究了超声波、牛血清蛋白(BSA)、表面活性剂Tween20和Tween80作为辅助手段对玉米秸秆酶水解过程的影响。结果显示:虽然三者作用机理不同,但是均能够提高酶水解得糖率。未加辅助方法时酶解48h后的得糖率为26.2%;经30W、10min超声波辐射辅助的酶解得糖率上升为35.7%;添加0.5g/LBSA时的酶解得糖率提高到32.8%;而加入1%的Tween20和Tween80后酶解得糖率分别增加到35.2%和35.9%。