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以正硅酸四乙酯(TEOS)与γ-甲基丙烯酰氧基丙基三甲氧基硅烷(MPS)为原料,采用一步缩合法制备MPS改性纳米SiO2,然后采用原位乳液聚合法制备改性纳米SiO2/短氟碳链聚合物复合乳液,通过红外光谱(FT-IR)、粒径分析、热失重分析(TGA)等方法分别表征产物结构、粒径及分布、热稳定性能,并对复合乳液整理后的涤纶织物进行拒水性能测试,利用扫描电子显微镜(SEM)表征整理前后织物的表面微观形态.结果表明:制备的复合乳液颗粒粒径分布均匀,具有较好的耐热稳定性,改性纳米SiO2的引入提高了整理织物的表面粗糙度,整理后织物对水的接触角达到151°,沾水等级达到90分,拒水性能明显提高. 相似文献
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纳米TiO2/SiO2的制备及光催化降解漂白废水中的苯酚 总被引:9,自引:2,他引:9
以钛酸四丁酯、正硅酸乙酯作为前驱体水解,用溶胶-凝胶法制备了纳米TiO2/SiO2复合物,用X-射线衍射(XRD)、透射电子显微镜(TEM)和紫外-可见光谱(UV-Vis)对其相组成和结构进行了表征.XRD分析表明,纳米TiO2/SiO2粒子在煅烧温度高达900℃时也未出现金红石型,而且随着SiO2含量的增加,TiO2/SiO.晶体颗粒越来越小.TEM照片显示,TiO2/SiO2纳米粒子形状基本为球形,粒径20~40nm.UV-Vis分析表明,SiO2含量的增加使得TiO2/SiO2吸收峰发生红移,吸光度也大大增加.另外,TiO2/SiO2粒子在降解苯酚的过程中表现出高催化活性,其中配比为90/10(Ti/Si质量比)的TiO2/SiO2粒子催化性能最好,其在125W紫外灯下照射8h后,苯酚的降解率达到83.1%. 相似文献
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通过溶胶-凝胶法制备了纳米SiO2溶胶,分析了pH、水解度、溶剂对凝胶时间和粒径的影响,确定了最佳工艺条件:溶剂是无水乙醇和蒸馏水的混合液,pH=3,水解度H2O/TEOS选择6:1。 相似文献
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将高吸附性SiO2水溶胶与低温制备的锐钛型纳米TiO2溶胶以不同的物质的量之比混合,再通过浸轧焙烘工艺将其负载于棉织物表面,得到SiO2/TiO2整理棉织物。测试了SiO2/TiO2整理棉织物的光催化作用,以及整理棉织物上SiO2含量对染料脱色率的影响。结果表明,当n(SiO2)∶n(TiO2)=1∶1~1∶3,它们能够形成粒径小且均匀的溶胶,在织物表面形成致密均匀的结晶薄膜,且SiO2/TiO2整理棉织物对染料有很佳的光催化活性。 相似文献
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采用次磷酸钠还原镍盐法,以特制SiO2为载体,制备了负载型非晶态合金Ni-P/SiO2大豆油加氢催化剂,在催化剂制备过程中对引发次磷酸钠还原镍盐反应的两种方法进行了比较,发现KBH4法明显优于NaOH法,研究了还原剂次磷酸钠和载体的用量对催化剂活性的影响。研究表明:在次磷酸钠还原镍盐中加入KBH4引发反应,次磷酸钠∶Ni2 =3∶1(摩尔比),SiO2∶Ni2 =1∶3(克数比)的条件下制备的催化剂在大豆油加氢中活性最高;催化剂最佳用量为0.5%。同时采用IR对原料和氢化产品进行了表征和说明。 相似文献
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为提高乳液稳定性,采用纳米SiO2改性明胶(gelatin,GE)、大豆分离蛋白、壳聚糖和阿拉伯胶(gum arabic,GA)制备茶油乳液。以乳化活性、乳化稳定性、离心稳定性、平均粒径、流变特性为考察指标,探究质量分数3.000%的纳米SiO2对4 种大分子材料复合乳液性质的影响,并对乳液的微观结构及油滴分布进行观察。结果表明,纳米SiO2能增强乳液稳定性,其中GE-纳米SiO2复合乳液综合性质最佳。添加纳米SiO2后乳化活性和乳化稳定性显著增加(P<0.05),离心稳定性降低68.444%。平均粒径为8.472 μm,乳液粒径最小且分布均匀,表面光滑呈球状。流变表现为典型的弱凝胶特性,稳定性良好。研究结果可为天然高分子和纳米SiO2乳液的制备和应用提供实践基础。 相似文献
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淀粉纳米颗粒的高效制备及吸附性能 总被引:1,自引:0,他引:1
以木薯淀粉为原料,在微波和超声波双外场的作用下采用沉淀法制备淀粉纳米颗粒(starch nanoparticles,SNPs)。通过动态光散射仪(dynamic light scattering,DLS)、场发射扫描电镜(scanning electronic microscope,SEM)、原子力显微镜(atomic force microscope,AFM)、比表面积分析仪(Brunner-Emmet-Teller,BET)对SNPs进行表征,考察了SNPs对番红花红T的吸附机理,进一步考察了时间、吸附剂的投加量、粒径对吸附的影响。结果表明:SNPs具有较好的球形形貌,是V型淀粉晶体结构,Zeta电位值为-23. 7 m V,比表面积大大增加。在番红花红T的质量浓度为200 mg/L,吸附时间为60 min,温度为298. 15 K的条件下,投加20 mg平均粒径为40 nm的SNPs,吸附量可达115 mg/g。SNPs对番红花红T的吸附过程符合准二级动力学模型和Langmuir等温吸附模型。 相似文献
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为解决在制备不同粒径的小球来实现全光谱结构色过程中工作量大的问题,采用溶剂调控法合成粒径均匀的304、260、200 nm的SiO2纳米颗粒,利用三原色加色法原理将3种不同粒径的纳米SiO2悬浮液按照不同质量比两两混合,然后放在烘箱中进行重力沉降自组装,制备出全光谱非晶光子晶体结构色薄膜,探究混合比例对SiO2光子晶体结构色的影响。同时为提高结构色的饱和度,将墨水添加到不同混合比例的SiO2悬浮液中,研究墨水质量分数对光子晶体结构色的影响。结果表明:随着小粒径SiO2比例的增加,结构色会出现蓝移现象;墨水质量分数越高,结构色亮度越低,色度呈先增加后减小趋势,当墨水质量分数为0.4%时,结构色饱和度最好。 相似文献
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针对硬质纳米微球所构筑的光子晶体在外力作用下结构易损坏,结构色耐久性差的问题,采用分步法合成内刚外柔型聚苯乙烯/聚(甲基丙烯酸甲酯-丙烯酸丁酯)(PS/P(MMA-BA))纳米微球,然后通过熔融剪切法快速制备柔性光子晶体结构生色膜。结果表明:纳米微球制备中内核交联剂二乙烯苯(DVB)可增加PS内核的交联密度和折光指数,使之与外层产生一定的折光指数差,且可与外层P(MMA-BA)共价连接;外层交联剂甲基丙烯酸烯丙酯(ALMA)可使纳米微球外层形成一定的交联点而提高外层的稳定性;当DVB用量为苯乙烯(St)的12.5%,ALMA用量为MMA与BA总量的0.3%时,光子晶体结构生色膜具有优良光学性质和力学性质,产生的结构色鲜艳明亮,且耐弯折、耐冲洗、耐摩擦;适应此类纳米微球组装的熔融剪切法,能快速大面积制备柔性光子晶体结构生色膜。 相似文献
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为减轻印染行业带来的环境问题,将生色效果良好的光子晶体结构色运用于针织物表面。首先制备大小均匀、粒径可控的二氧化硅(SiO2)纳米颗粒,然后通过重力沉降法将颗粒自组装到不同的针织物表面获得结构色。探讨了SiO2颗粒粒径、自组装温度、织物组织结构对针织物表面结构色显色效果的影响。结果表明:不同粒径的SiO2纳米颗粒在针织物上产生了不同的结构色,结构色的反射波峰的波长由SiO2的粒径决定,且符合布拉格衍射定律;在其他实验条件相同的情况下,较低温度的自组装所得到的结构色显色效果较好,较光滑的纬平针织物的显色效果要更优。 相似文献
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本文采用流延法制备了一系列甘油增塑、与海藻酸钠共混改性的大豆分离蛋白/海藻酸钠复合膜,并利用热重分析方法对这些复合膜的热分解性能进行了考察.热分解实验中,通过改变升温速率,研究甘油含量对大豆分离蛋白/海藻酸钠复合膜热分解性能的影响.从所得到的TGA和DTA曲线可知,大豆分离蛋白/海藻酸钠复合膜的热分解行为可以分为三个较明显的降解阶段.根据失重速率的变化确定热分解反应最剧烈的温度区间为420 ~630K,对此采用Coats-Redfern方法进行了热分解动力学分析,并得出该阶段为一级热分解反应的结论.通过动力学模型,可以计算得到这些复合膜热分解反应的动力学参数,如表观活化能和指前因子.实验结果显示,甘油的加入使复合膜更易热分解;计算也表明热分解活化能随着甘油量的增加而不断下降,降幅可达50%. 相似文献
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ABSTRACTFabrication and characterization of keratin films extracted from waste Merino wool fiber using two different methods and three different pH concentrations is the main focus of this study. Also, wool keratin (WK) loaded polymer surfaces were fabricated. The chemical, structural and morphological characteristics of keratin extracted from aqueous solutions were analyzed and compared for both methods. It is concluded that optimized results in this study could contribute in future research studies to select the parameters and methods to extract keratin films from recyclable wool fibers. Also, WK loaded nanofibrous films could be potential in filtration, air purification and tissue engineering. 相似文献
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Different starch types (corn, rice, potato, corn amylose and corn amylopectin) were phosphorylated to varying degrees of substitution (DS) and tested both for acid hydrolysis during 3 h in a boiling bath and for enzymatic hydrolysis with a thermostable bacterial α‐amylase (Bacillus licheniformis) for 30 min at 95 °C. Generally, phosphorylated starches showed a reduced degree of acid hydrolysis during the entire time of hydrolysis (3 h) as well as reduced susceptibility to α‐amyIase hydrolysis. The enzyme action was inhibited by the presence of phosphate groups in the modified starch molecules and the extent of inhibition increased with increasing degree of phosphate substitution, regardless of the starch type. Thermoplastic films were fabricated by blending modified corn starches of different DS with polyacrylate, urea and water at a ratio of 4:5:1:50, heating for 30 min at 95 °C before casting and allowing to cool, stand and dry at room temperature. The plastic films prepared from phosphorylated corn starch showed both higher disintegration rate and a greater degradability by thermostable bacterial α‐amylase than the ones prepared from non‐phosphorylated starch. These new acquired properties can meet the increasing demand for biodegradable disposable plastic bags. 相似文献
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Muhammad Javeed Akhtar Muriel JacquotElmira Arab-Tehrany Claire GaïaniMichel Linder Stéphane Desobry 《Food chemistry》2010
The efforts are being made to design protective hydroxypropyl methylcellulose (HPMC) colour packages to avoid photo-oxidation of edible fats and oils. In the present study, edible films of HPMC containing different edible colours like blue, green, yellow, red and white were tested for their ability to avoid photo-oxidation in salmon oil. The samples taken in petri-dishes and covered with coloured HPMC films of thickness 40 μm were placed under fluorescent light at 20 °C. During storage, chemical parameter of oil quality such as fat oxidation was monitored during 8 days of storage. Oxygen consumption by gas chromatography, conjugated diene values by spectrophotometery and fatty acid composition by gas chromatography (GC) was measured. The results of our study show that HPMC films with suitable edible colours act as adequate light barrier to avoid photo-oxidation of salmon oil during extended storage. HPMC films containing white, red and yellow edible colours show good control of oil photo-oxidation almost similar to the control samples stored in darkness. Oil samples treated with blue and green edible films show gradual increase in oil oxidation with increasing time of light exposure. Oxidation behaviour of samples treated with blue and green films was almost similar to the samples stored in transparent films. 相似文献
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Marina P. Arrieta Mercedes A. Peltzer María del Carmen Garrigós Alfonso Jiménez 《Journal of food engineering》2013
Edible active films based on sodium caseinate (SC) and calcium caseinate (CC) plasticized with glycerol (G) at three different concentrations and carvacrol (CRV) as active agent were prepared by solvent casting. Transparent films were obtained and their surfaces were analysed by optical microscopy and scanning electron microscopy (SEM). The influence of the addition of three different plasticizer concentrations was studied by determining tensile properties, while Fourier transformed infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to evaluate the structural and thermal behavior of such films. The addition of glycerol resulted in a reduction in the elastic modulus and tensile strength, while some increase in the elongation at break was observed. In general terms, SC films showed flexibility higher than the corresponding CC counterparts. In addition, the presence of carvacrol caused further improvements in ductile properties suggesting the presence of stronger interactions between the protein matrix and glycerol, as it was also observed in thermal degradation studies. FTIR spectra of all films showed the characteristic bands and peaks corresponding to proteins as well as to primary and secondary alcohols. In summary, the best results regarding mechanical and structural properties for caseinates-based films containing carvacrol were found for the formulations with high glycerol concentrations. 相似文献
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目的:采用仿生硅化法实现对胰蛋白酶的固定,并将固定化酶与聚甲基丙烯酸甲酯(PMMA)相结合用于抗生物粘泥复合膜的制备。方法:研究了正硅酸甲酯(TMOS)与酶的浓度比、介孔氧化硅(MPS)与酶的质量比、有机溶剂等因素的影响。并以MPS固定化酶为对照实验,对复合膜酶的稳定性、催化活性、重复使用性、抗蛋白质吸附性能等进行了分析。结果:通过仿生硅化法制备的仿生氧化硅-酶-聚甲基丙烯酸甲酯复合膜(Si O2-Enzyme-PMMA film),与介孔氧化硅-酶-聚甲基丙烯酸甲酯复合膜(MPS-Enzyme-PMMA film)相比,具有更好的稳定性,在25℃和50℃储藏30 d后,两种膜酶活性分别为86.3%和81.2%。Si O2-Enzyme-PMMA film在重复使用6次之后,复合膜的酶活剩余89.1%。将复合膜浸泡在牛血清白蛋白(BSA)溶液中18 d后,其表面蛋白质吸附量仅为不含酶PMMA的三分之一。两种复合膜均具有良好的抗蛋白吸附性能。结论:仿生硅化制备固定化酶,与介孔氧化硅载体相比,在提高固定化酶的包埋率和稳定性方面有更显著的优势,其条件温和,操作简便,活性高,应用于抗生物粘泥涂层具有更好的防污效果。 相似文献
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Tohru Okamoto Yuji Matsushita Eiko Matsuura† Masaru Masuda† 《International journal of cosmetic science》2006,28(2):152-152
We developed a preparation method for visible emulsion droplets (0.05–3 mm) consisting of a solid type oil and a liquid type oil. It was found that (1) using amphiphiles as the solid oil gave a spherical and visible sized particle and (2) behenyl alcohol was the most preferable amphiphile to make a large sized particle. DSC measurement and microscopic observation of the particle showed that the amphiphilic solid oil built a shell on the outer side of the particle and the shell protected the emulsion against aggregation and coalescence. It was found that the preparation of an extremely large emulsion could create innovative functions in the cosmetic field. The visible sized emulsion could provide a freshening feel in the early stages of the application and an emollient feel after rubbing into the skin. Furthermore, since this emulsion could protect an unstable lipophilic material from hydrolysis, it offers a suitable storage for useful cosmetic ingredients such as lipophilic drugs and hydrophobic powders. 相似文献