纳米SiO_2改性相变储热微胶囊的制备及性能研究

以亲水型纳米SiO2粒子改性的三聚氰胺一甲醛树脂作为微胶囊壁材,以相变材料正十二醇为芯材,采用原.位聚合法,制备了纳米SiO2改性的相变储热微胶囊,研究了纳米SiO2粒子对微胶囊性能的影响,采用FTIR、DSC和SEM等方法进行了表征.结果表明,当壁材中加入适量的纳米SiO2时,纳米粒子在壁材里面分布均匀,微胶囊的相变焓提高,破损率降低,且纳米SiO2不会破坏预聚体的缩聚反应.当壁材中纳米SiO2质量分数为1%时,制备的微胶囊相变焓达148.7J/g,微胶囊破损率为23.1%.     

功能性空调过滤器材料的性能实验研究

开创性地把光催化技术和微胶囊相变材料技术有机地结合起来,开发了纳米微胶囊相变功能型空调过滤器材料,在对它的杀菌效果和调温等性能研究的基础上,分析了空调过滤器的过滤机理,设计了实验流程,参照ANSI／AHAMAC-1—1988标准建造了实验室,对功能型空调过滤器过滤效率进行了实验。最后对实验结果进行了一定的分析,并展望了功能型空调过滤器材料的应用前景。     

添加相变材料微胶囊的聚氨酯泡沫制备及表征

在聚氨酯发泡体系中加入正十八烷微胶囊,制备含有相变材料微胶囊的聚氨酯泡沫.相变材料微胶囊能很好的埋置于聚氨酯基体中,泡沫的储热量随微胶囊含量的增大而增大,舍有20%(wt)相变材料微胶囊的泡沫储热量为24.7J/g,该泡沫可用作保温材料.     

纳米TiO2修饰壳聚糖/石蜡相变微胶囊的制备与性能研究

以36℃相变石蜡为芯材，天然高分子壳聚糖为壁材，纳米二氧化钛(TiO₂)修饰壳体，利用乳化交联法制备了具有抗紫外功能性的相变微胶囊。探讨了不同因素对微胶囊性能的影响，经实验优化，当乳化剂用量为10%,油水相比例为3∶1,纳米TiO₂添加量为0.12g时，制得的相变微胶囊包覆率可达81.61%。通过扫描电镜、差示扫描量热仪、热重分析仪和紫外-可见分光光度计等分析，结果表明相变微胶囊表面光滑、形态规整，相变潜热为118.90J/g,具有良好的热循环和热稳定性，以及紫外屏蔽功能性。     

纳米SiO_2和石墨改性相变储热微胶囊的研究

以固体石蜡为相变芯材,三聚氰胺-尿素-甲醛共缩聚树脂为囊壁,采用原位聚合法制备了微胶囊型相变储热材料;并针对该相变材料热导率低及亲水性差缺点,用石墨和纳米SiO2对芯材和微胶囊进行了导热性和表面性能的改性研究。采用光学显微镜(OM)、红外光谱仪(FTIR)、差示扫描量热仪(DSC)、热重分析仪(TGA)等对产品的表面形态、化学结构、热性能等进行了测试和表征。结果表明:石蜡微胶囊化后能保持原有的储热特性,相变焓为47.5J/g;球状微胶囊平均粒径为45μm,表面粗糙,石蜡包封率达80%;纳米SiO2改性后微胶囊亲水性、耐热性能、机械强度均增强;石墨改性后导热性提高。     

有机无机杂化囊壳型微胶囊相变材料的研究进展

主要论述了传统微胶囊相变材料的的制备方法。介绍了以有机无机杂化材料为囊壳的微胶囊相变材料的优势,并总结了3种不同的制备方法,包括纳米粒子填充法,溶胶-凝胶法和Pickering乳液法。着重讨论了Pickering乳液在有机无机杂化囊壳微胶囊相变材料中的应用。     

界面聚合法制备微胶囊相变材料的试验研究

以相变石蜡为芯材,廉价的聚脲和聚氨酯为壁材,采用界面聚合法制备了单层和双层壁材微胶囊相变材料,并用差示扫描量热仪(DSC)和TG分析仪分别对所制备的单层壁材微胶囊和双层壁材微胶囊进行了测试.结果表明,与同条件下制备的单层壁材微胶囊相比,双层壁材微胶囊在合成过程中反应充分、产率较高,在室温环境下相变温度为19.02℃,且保持了较高的相变潜热(79.9J/g),适合于建筑用相变材料.     

不同乳化剂作用下三聚氰胺-甲醛@正十八烷微胶囊相变复合材料微观形貌和热性能

采用原位聚合法,通过改变非离子/阴离子乳化剂组合制备了一系列以正十八烷(OD)为芯材、三聚氰胺(M)-甲醛树脂(F)为壁材的微胶囊相变储能材料,并借助FTIR、SEM、DSC和激光粒度分析仪等手段系统研究了乳化剂复配对M-F@OD微胶囊相变材料微观形貌和相变潜热的影响。结果表明,不同乳化剂组合及掺量对M-F@OD微胶囊相变材料的形貌和性能产生显著影响,当采用非离子和阴离子复合乳化剂时,M-F@OD微胶囊相变材料团聚现象得到明显改善,粒径分布更加均匀,颗粒尺寸进一步细化,粒径大小范围为0.1~1μm,储热能力明显提高,相变潜热达到70.86J/g。     

微胶囊相变材料的制备与特性研究

采用原位聚合法制备以石蜡为芯材、脲醛树脂为壳材的微胶囊相变材料,并通过丝网印刷技术,结合热固性聚氨酯网印粘合剂将微胶囊涂布于棉布上.考察了乳化剂的种类及用量和人工汗液对微胶囊性能的影响,分析了对经MCPCM涂布的棉布布料的热性能.研究结果表明,使用复合乳化剂制备的微胶囊相变材料表面光滑,密封良好.微胶囊相变温度和相变潜热分别为34.10℃和143.8J/g,经过20次热循环后,相变温度和相变潜热都变化不大.微胶囊经人工汗液分别浸渍20min、40min和60min 后,其相变温度和相变潜热无明显变化.微胶囊与网印粘合剂结合的复合材料涂布于棉布上,其相变温度和相变潜热均有降低.     

聚乙烯醇/相变微胶囊多孔定形复合相变材料的制备及性能

实验中将相变微胶囊乳液与聚乙烯醇(PVA)溶液复合,通过物理发泡法制得具有形状记忆性能的多孔定形复合相变材料,研究了相变微胶囊对多孔定形复合相变材料孔结构及吸水保水性、相变性能、形状记忆性能等的影响。结果表明,所制备多孔定形复合相变材料的孔结构随着微胶囊乳液用量的增大出现并泡现象,孔径与开孔率增大;吸水率与保水率明显提高,吸水率最大可达1025%;相变焓值随相变微胶囊乳液用量的增大而增大,可达10.85 J/g,具有良好的相变储热性能;多孔定形复合相变材料经弯折形变固定后,热致形变回复率5 min内可达77.8%,湿致形状回复率在1 min内可达到83.3%,具有较好的形状记忆特性。     

镁合金Ni-Ce-P/纳米TiO2化学复合镀工艺及性能

为了改善镁合金表面的耐磨、耐蚀及抗茵性能,在Ni-ce-P化学镀的基础上加入了纳米TiO2,在镁合金上获得了Ni-ce-P/纳米TiO2化学复合镀层,对复合镀层组织进行了分析.最佳工艺参数:25.0 g/L.NiSO4·6H2O,2.0 g/L TiO2,20.0 g/L柠檬酸,25.0 g/L NaH2PO2·H2O,10.0 g/L NH4HF2,0.1 g/LCe(N03)3,0.2 g/L硫脲,2.0 g/L十二烷基硫酸钠,时间1 h,磁力搅拌.结果表明:Ni-Ce-P/纳米Ti02化学复合镀层使镁合金的耐磨性提高了1倍,耐蚀性优异,光催化性及抗茵性能良好.     

Antibacterial hydroxyapatite/chitosan complex coatings with superior osteoblastic cell response

Chitosan was widely used as an antibacterial component. While most antibacterial materials also possess cytotoxicities, we hypothesize that selectively destruction of bacterial cells can be achieved by controlling the material parameters of chitosan, due to its intrinsic antibacterial mechanism. In this study, porous hydroxyapatite coatings prepared by the liquid precursor plasma spraying process were used for loading the chitosan with different concentrations: 10, 20, 50, and 100 g/L, respectively. The antibacterial properties and osteoblastic cell response of the hydroxyapatite/chitosan complex coatings were studied as a function of chitosan concentration. The results indicated that the antimicrobial activity was directly proportional to the chitosan concentration, while loading of chitosan with lower concentrations (10 and 20 g/L) was even beneficial to the proliferation of osteoblastic cells. Overall, our study demonstrated that combined antibacterial activity and superior osteoblast cell response can be achieved by using hydroxyapatite/chitosan complex coatings, which have great potential in bone replacement and regeneration applications.     

载银沸石对纸张抑菌防霉性能及 印刷适性的影响

研究了不同添加质量(或添加质量浓度)的载银沸石对牛皮纸、白卡纸和铜版纸的抑菌防霉效果及机械性能、白度、平滑度等印刷适性的影响。结果表明:1)当纸张中载银沸石的添加质量浓度为1000mg/L时,大肠杆菌的抑菌环直径达21.5mm,由此可知,载银沸石能较好地抑制大肠杆菌的生长。2)当纸张中载银沸石的添加质量为1.0g时,纸张完全无霉菌生长,且纸张边缘的菌丝也未见长出,由此可知,载银沸石对黑曲霉具有一定的抑制效果。3)不同添加质量的载银沸石对纸张的机械性能、白度和平滑度有一定影响,但影响较小。故当载银沸石的添加质量为0.5～1.0g时,纸张不仅具有较好的抑菌防霉效果,且其机械性能、白度和平滑度没有明显变化。     

Biocompatible nano-gallium/hydroxyapatite nanocomposite with antimicrobial activity

Intensive research in the area of medical nanotechnology, especially to cope with the bacterial resistance against conventional antibiotics, has shown strong antimicrobial action of metallic and metal-oxide nanomaterials towards a wide variety of bacteria. However, the important remaining problem is that nanomaterials with highest antibacterial activity generally express also a high level of cytotoxicity for mammalian cells. Here we present gallium nanoparticles as a new solution to this problem. We developed a nanocomposite from bioactive hydroxyapatite nanorods (84?wt %) and antibacterial nanospheres of elemental gallium (16?wt %) with mode diameter of 22?±?11?nm. In direct comparison, such nanocomposite with gallium nanoparticles exhibited better antibacterial properties against Pseudomonas aeruginosa and lower in-vitro cytotoxicity for human lung fibroblasts IMR-90 and mouse fibroblasts L929 (efficient antibacterial action and low toxicity from 0.1 to 1?g/L) than the nanocomposite of hydroxyapatite and silver nanoparticles (efficient antibacterial action and low toxicity from 0.2 to 0.25?g/L). This is the first report of a biomaterial composite with gallium nanoparticles. The observed strong antibacterial properties and low cytotoxicity make the investigated material promising for the prevention of implantation–induced infections that are frequently caused by P. aeruginosa.     

含季鏻阳离子的抗菌改性蒙脱土的制备及表征

采用离子交换法将十六烷基三苯基插入到钠基蒙脱土的层间得到4种不同季鏻阳离子含量的改性蒙脱土,通过热重分析（TGA）、X射线衍射法（XRD）和扫描电镜（SEM）表征了结构,并测试了其Zeta电位和抗菌活性. 发现4种改性蒙脱土中季鏻阳离子的热分解起始温度都高于230℃,具有较好的热稳定性. 并且随着改性蒙脱土中季鏻阳离子含量的增加,其层间距变大、Zeta电位升高、抗菌活性增强. 钠基蒙脱土为片状结构,粒子之间相互缠绕在一起,而改性蒙脱土显示不规则形状. 对季鏻阳离子含量为23.55wt%的QPC/MMT 3样品,其对大肠杆菌（E.coli）和金黄色葡萄球菌（S.aureus）的最低抑菌浓度（MICs）分别为1.2和0.1g/L;与细菌接触24h后,1.0g/L的样品可杀死99.9%以上的E.coli,0.1g/L的样品可杀死所有的S.aureus. QPC/MMT 3还具有较好的耐水性能.     

304Cu抗菌不锈钢盐酸基酸洗工艺的研究

为了明确盐酸基酸洗液对含Cu抗菌不锈钢表面氧化层的酸洗行为,采用正交试验法研究以盐酸为基础,Fe~(3+)、H_2O_2和HNO_3为氧化剂的304Cu抗菌不锈钢酸洗工艺.并运用扫描电镜、透射电镜及电化学等手段分析经最佳配方酸洗后试样的表面形貌、成分及酸洗机理.结果表明:最佳酸洗工艺配方为HCl(36%~38%)120 ml/L、H_2O_2(30%)80 ml/L、FeCl_3·6H_2O 20g/L、HNO_310 ml/L,酸洗温度30℃,酸洗时间15 min.经该配方酸洗后材料表面平整度和光亮度较好,具有抗菌性能的点状ε-Cu相在基体上弥散分布.材料经酸洗去除氧化层后,仍具有足够含量的抗菌元素Cu存在.酸洗脱除氧化层过程由电荷传递过程控制,该酸洗液对不锈钢具有孔蚀诱导性,酸洗时间不宜过长.     

利用南瓜蒸煮液绿色制备纳米银及其抑菌性能的研究

目的 以南瓜蒸煮液和AgNO3为原料,烷基糖苷(APG)为表面活性剂,以微波加热绿色制备纳米银溶胶,研究其制备工艺、性能和抑菌效果。方法 以单因子对纳米银的制备进行优化。通过紫外-可见吸收光谱(UV-vis)、透射电镜(TEM)、能量色谱(EDS)和X射线衍射(XRD)等方法对合成纳米银的特征吸收峰、形貌以及稳定性等进行分析,并考察纳米银对大肠杆菌(E.coli)和金黄色葡萄球菌(S.aureus)的抑菌性能。结果 纳米银制备适宜的优化工艺条件:在南瓜蒸煮液体积为40 mL情况下,AgNO3的初始质量浓度为1.2 g/L、pH值为13、微波加热时间为60 s。经优化后,所制备的纳米银的UV-vis光谱在406 nm处出现强的特征吸收峰,EDS色谱进一步证实了纳米银的存在。纳米银为球形,平均粒径为13.4 nm,粒径小,分散性和稳定性好。抗菌试验表明,不同质量浓度的纳米银对E.coli和S.aureus均有较强的抑制和杀灭效果,对E.coli的MIC值和MBC值分别为5 mg/L和10 mg/L,对S.aureus的MIC值和MBC值分别为40 mg/L和320 mg/L。结论 该AgNPs对革兰氏阴性和革兰氏阳性细菌具有抗菌能力,在食品包装中具有较好的应用前景。     

低聚壳聚糖复配体系对皮肤致病菌的体外抗菌活性研究

采用药敏纸片法和对倍稀释法分别考察了低聚壳聚糖与茶树油对化脓性链球菌、表皮葡萄球菌、金黄色葡萄球菌和大肠杆菌的抑菌性和最小抑菌浓度(MIC);采用定量法测定了低聚壳聚糖和茶树油复配体系的杀菌率,并与单组分杀菌率进行对比。结果表明:低聚壳聚糖和茶树油对4种实验菌均有抑菌性的MIC分别为0.5g/L和7.50mL/L;0.5g/L低聚壳聚糖与7.50mL/L茶树油复配后,对4种实验菌均有优异的杀菌率,复配体系明显优于单组分杀菌效果,其20min杀菌率均达到100%。     

Preparation and antibacterial character of a water-insoluble antibacterial material of grafting polyvinylpyridinium on silica gel

Micron-sized silica gel particles were modified with the coupling agent of 3-methacryloylpropyl trimethoxysilane (MPS), then the copolymer of 4-vinyl pyridine and acrylamide (P (4VP-co-AM), PVA) was grafted onto the surface of modified silica gel particles by adopting the “grafting from” way, and the grafted particles PVA/SiO₂ were obtained. Finally, PVA on the particles PVA/SiO₂ were quaternarized by using benzyl chloride or dimethyl sulfate as quaternization reagents, and a kind of water-insoluble antibacterial material QPVA/SiO₂ with pyridinium-type was prepared. In this paper, the antibacterial property of QPVA/SiO₂ was mainly investigated by using Escherichia coli (E. coli) as model bacterium and by the colony count method, the effects of the grafting degree of pyridinium and the variety of quaternization reagents on the antibacterial property of QPVA/SiO₂were examined, and the antibacterial mechanism of QPVA/SiO₂ was explored using the method of measuring the activities of β-d-galactosidase and TTC-dehydrogenase. The experiment results show that QPVA/SiO₂ possesses strong antibacterial ability, and the antibacterial ratio of QPVA/SiO₂ with 2.3 mmol/g of grafting degree of pyridinium can reach 100% for bacterium suspension of 10⁹ CFU/mL with the dosage of 20 g/L and for 10 min of contact time. The greater the grafting degree of pyridinium is, the stronger the antibacterial ability, and the antibacterial property of the QPVA/SiO₂ prepared using benzyl chloride as quaternization reagent is stronger than that of the QPVA/SiO₂ prepared using dimethyl sulfate. The experimental results of two kinds of enzyme activity measurements reveal that the antibacterial effect of QPVA/SiO₂ is based on a sterilization process and not only based on a restraining action.     

铜原位改性HMS材料的表征及抗菌性能

采用溶胶凝胶法,原位合成了铜改性的六方介孔硅 (Cu-HMS)无机抗菌材料. XRD、TG-DTA、ESR、UV-Vis、FT-IR、ESEM、EDS及N₂吸附脱附等对材料结构与性能进行了表征;以大肠杆菌、金黄色葡萄球菌、枯草杆菌及芽孢杆菌作供试菌种,考察了材料的抗菌性能. 结果表明,材料粒子呈规则的叶片状,比表面积为553m²/g,平均孔径约3.6nm,铜以离子形式存在于材料的骨架结构中,材料具有良好的介孔结构和热稳定性,有优良的紫外-可见光吸收性能;在抗菌实验中,材料的抗菌效能较好,抗菌性能稳定持久. 材料用量20mg/L,12h即表现出明显的抑菌作用;用量为200mg/L时,24h后可彻底杀灭大肠杆菌、金黄色葡萄球菌及枯草杆菌.