负载荧光分子的EVA乳胶用于NIR-Ⅱ指纹成像应用

NIR-Ⅱ荧光分子通常在固体状态下表现出聚集淬灭问题,严重阻碍了其在荧光传感领域的应用。本工作利用醋酸乙烯-乙烯共聚乳胶(EVA乳胶)聚合物易于改性的特点,采用共混干燥方法将NIR-Ⅱ荧光分子分散至EVA乳胶粉中,实现了其固态荧光抗淬灭的目的。此外,制备的NIR-Ⅱ-EVA乳胶粉通过喷壶喷洒的方式实现了简便、快速的NIR-Ⅱ指纹荧光显影应用。本研究为NIR-Ⅱ荧光分子的固态发光性质调控提供了新的策略,并拓展了EVA乳胶在生物信息传感等领域的应用潜力。

改性EVA胶粒的TEM研究

用磷钨酸 ( PTA)对改性 EVA乳胶作电子染色 ,用透射电镜 ( TEM)观察了染色后的胶粒。结果表明 :用 TEM表征改性 EVA胶粒快捷、可靠。清晰的图像说明染色剂 PTA的应用是非常必要的。

雾化盘转速对EVA可再分散乳胶粉性能的影响(英文)

以聚乙烯醇(PVA)为保护胶体,硅溶胶及无机粉体为抗结块剂,采用喷雾干燥法制备了乙烯-醋酸乙烯酯(EVA)可再分散乳胶粉,着重讨论了雾化机旋转盘的转速对EVA可再分散乳胶粉及其性能的影响.实验结果表明,雾化机旋转盘的转速对乳胶粉的外观、含水率、流动性、堆积密度、再分散及成膜性能有较大的影响.雾化机旋转盘的转速升高,乳胶粉含水率降低,流动性提高,堆积密度下降,粒径减小,再分散性和成膜性能都有所提高.FTIR测试显示,制备的聚合物乳胶粉分子结构未发生明显改变.

EVA乳胶粒电镜观察中的染色技术

选用磷乌酸 ( PTA)作电子染料 ,对 EVA乳胶作各种染色处理 ,用透射电镜观察其结果 ,分析并比较了染液不同 p H值 ,不同用量以及不同染色时间和方法等对观察结果的影响 ,实验结果表明 PTA染色有助于胶粒核壳结构的体现 ,p H6.4PTA染色效果好。

Effect of Curing Regime on Bonding Strength of EVA Modified Mortar to Tile

Ethylene-Vinyl Acetate （EVA） redispersible powder and latex were used to modify mortar. Three kinds of curing regimes： standard curing, high temperature curing and freeze-thaw circle curing were adopted to cure the bonded samples. Bonding strength of EVA modified mortar was tested at 28 days. The development of bonding strengths under all three curing regimes were discussed and compared. The experimental results show that bonding strength increases with the increase of EVA content in mortar. The curing regime used within 28 days is critical according to the bonding strengths values under three curing regimes for different ages. The reasons of that the EVA can improve the bonding strength were analyzed.

Influence of Curing Condition on the Adhesive Strength of EVA Modified Mortar to Tile

The reducing water effectiveness of EVA latex and powder was observed. Adhesive strength of EVA modified mortar to tile under different curing condition was studied. And the adhesive strengths of mortars modified by EVA latex and by EVA powder were compared. The results show that the reducing water effectiveness is improved by 36.12% and 21.55%, respectively, when the content of EVA latex and powder are 8% and 4%. EVA latex and powder can improve the adhesive strength of modified mortar to tile under the standard curing, high temperature curing, and freeze-thaw circle curing. EVA latex can improve the water resistance obviously, besides improve the adhesive strengths of standard curing and high temperature curing, comparing with EVA powder.

乳胶/EVA/LDPE/PVC共混发泡片材的研制

采用模压发泡成型工艺研究了乳胶/EVA/LDPE/PVC四元共混发泡片材的制备方法,着重讨论了橡塑比,发泡剂、交联剂、填充剂等用量对微孔发泡体物理机械性能的影响,并用电镜扫描观察了发泡体的断面构造,实验结果表明,该共混发泡体材料质轻,物理机械性能良好;该四元共混的工艺技术具有实用价值和经济效益。

低成本水性外墙浮雕涂料

以EVA乳液、硅溶胶为主要成膜物质,玻璃纤维为增强抗裂成分,加入适量填料及助剂配制成低成本水性外墙浮雕涂料。讨论了原材料的选择及生产成本,并通过了工程实际使用。结果表明,浮雕斑点圆润、硬度高、耐水性好,是一种实用型的建筑外墙涂料。

不同养护方式下可再分散乳胶粉改性砂浆的性能

研究了三种不同养护方式(60℃蒸汽养护、饱和石灰水浸泡养护、早期水中-后期空气中养护)对掺入不同剂量的乙烯-醋酸乙烯共聚物可再分散乳胶粉(EVA乳胶粉)改性砂浆性能的影响规律。结果表明:随着EVA乳胶粉掺量的增加,砂浆的流动度先增大后减小,吸水率先减小后增大,且EVA掺量为4%时,砂浆流动性最好,掺量为6%时砂浆吸水率最小;砂浆抗折强度先增大后减小,且在4%掺量时取得最大值,而抗压强度一直减小,砂浆的压折比呈现出先减小后保持基本不变,并在4%乳胶粉掺量时有较低值;蒸汽养护最有利于聚合物砂浆结构的致密及强度的发展,而饱和石灰水浸泡养护对其致密性和强度最不利。