抗菌再生纤维素纤维的制备与表征

利用实验室合成的非水溶性抗菌剂——聚六亚甲基胍十二烷基苯磺酸盐(PHGDBS),与纤维素共同溶解于离子液体中,经干喷湿纺制备了抗菌再生纤维素纤维,并研究了PHGDBS对纤维结构性能的影响。结果表明:所合成的PHGDBS能够溶解于离子液体中,且对细菌和真菌均有很好的抗菌效果。PHGDBS质量分数为2%时制备的再生纤维素纤维,对金黄色葡萄球菌和大肠埃希菌的抗菌率分别达99.7%和94.5%;经水洗15次后,抗菌率仍保持在90%以上。另外,PHGDBS的加入对纤维的表面和截面形态无显著影响,虽然再生纤维素纤维的结晶度和取向度减小,纤维的断裂强度有所下降,但仍可以满足服用性能。     

N-Halamine-Based Antimicrobial Additives for Polymers: Preparation, Characterization and Antimicrobial Activity

A series of 3-alkyl-5,5-dimethylhydantoin derivatives were prepared by reacting 5,5-dimethylhydantoin with alkyl bromides with different alkyl chain length (C-2 to C-22). Upon chlorination, the hydration derivatives were transformed into 1-chloro-3-alkyl-5,5-dimethylhydantoins (CADMH). The structures of the samples were fully characterized with FT-IR, (1)H NMR, UV, and DSC analyses. The antimicrobial functions of CADMH were challenged with 10(8-9) CFU/mL of Escherichia coli (gram-negative bacteria) and Staphylococcus aureus (gram-positive bacteria). All the samples provided a total kill of the gram-negative and gram-positive bacteria in less than 30 min. CADMH were used as antimicrobial additives for polymeric materials. It was found that the presence of as low as 1% of CADMH could provide the samples with potent antimicrobial functions. The structure-antimicrobial efficacy relationships of the CADMH were further discussed.     

Biodegradable Polycaprolactone-Titania Nanocomposites: Preparation,Characterization and Antimicrobial Properties

Nanocomposites obtained from the incorporation of synthesized TiO₂ nanoparticles (≈10 nm average primary particle size) in different amounts, ranging from 0.5 to 5 wt.%, into a biodegradable polycaprolactone matrix are achieved via a straightforward and commercial melting processing. The resulting nanocomposites have been structurally and thermally characterized by transmission electron microscopy (TEM), wide/small angle X-ray diffraction (WAXS/SAXS, respectively) and differential scanning calorimetry (DSC). TEM evaluation provides evidence of an excellent nanometric dispersion of the oxide component in the polymeric matrix, with aggregates having an average size well below 100 nm. Presence of these TiO₂ nanoparticles induces a nucleant effect during polymer crystallization. Moreover, the antimicrobial activity of nanocomposites has been tested using both UV and visible light against Gram-negative Escherichia coli bacteria and Gram-positive Staphylococcus aureus. The bactericidal behavior has been explained through the analysis of the material optical properties, with a key role played by the creation of new electronic states within the polymer-based nanocomposites.     

Linalool Nanoemulsion Preparation,Characterization and Antimicrobial Activity against Aeromonas hydrophila

Aeromonas hydrophila is one of the most important aquatic pathogens causing huge economic losses to aquaculture. Linalool, a vital ingredient of a variety of essential oils, was proved as a good antimicrobial agent in our previous studies. However, the low solubility and volatility of Linalool obstruct its application in the field of aquatic drugs. Thus, in this study, Linalool nano-emulsion (LN) was prepared to solve these obstructions. We investigated the physicochemical properties, antibacterial activity, and mode of action of LN against A. hydrophila. LN with different medium chain triglycerides (MCT) concentrations were prepared by ultrasonic method. The results showed that the emulsion droplet size of LN was the smallest when MCT was not added to the formulation. Nano-emulsions are usually less than 500 nm in diameter. In our study, LN in this formulation were spherical droplet with a diameter of 126.57 ± 0.85 nm and showed good stability. LN showed strong antibacterial activity, the MIC and MBC values were 0.3125% v/v and 0.625% v/v, respectively. The bacterial population decreased substantially at 1 × MIC of LN. LN exhibited disruptive effect on cell membranes by scanning electron microscope (SEM) and transmission electron microscope (TEM). The present study provided a formulation of Linalool nano-emulsion preparation. Moreover, the good antibacterial activity of LN showed in our study will promote the application of Linalool for the control and prevention of A. hydrophila in aquaculture.     

用作颜填料的单分散聚合物微球的研制

以二乙烯基苯（DVB）为单体,偶氮二异丁腈（AIBN）为引发剂,乙腈为溶剂,用沉淀聚合法合成了高交联度的聚合物微球。讨论了反应时间、反应温度、转动速率、单体浓度以及引发剂浓度对聚合物微球粒径及粒径分布的影响,并用扫描电子显微镜（SEM）进行了表征。     

Preparation and Characterization of Conductive Polyaniline/Silver Nanocomposite Films and Their Antimicrobial Studies

Silver (Ag) nanoparticles are known to hold an important place in nanotechnology, and studies herein present the preparation and characterization of Ag metallic nanoparticles bearing antibacterial properties. In situ polymerization was used to prepare the conductive polymer polyaniline (PANI) and polyaniline/silver (PANI/Ag) nanocomposites. Increases in electrical conductivities of the nanocomposite films were observed compared to neat PANI, whereby these increases may be a result of the Ag doping effect or its complex formation. Spectroscopic techniques, such as, UV–Vis, FTIR, and photoluminescence were used for the characterizations of PANI and PANI/Ag nanocomposites. UV–Vis and FTIR data showed the quinoid units along the polymer chain being affected, such that strong interactions between Ag nanoparticles and quinoidal sites of PANI were presumed. The PANI/Ag nanocomposites showed higher photoluminescence intensities than neat PANI. TGA analyzes were used to determine weight losses and thermostabilities of PANI and PANI/Ag nanocomposites. Scanning electron microscopy was used for morphological evaluations of the nanoparticles and films, where the micrographs revealed that Ag nanoparticles were well dispersed and isolated in nanocomposite films. The presence and distribution of the Ag nanoparticles in PANI film matrix were analyzed by EDX. Antimicrobial properties of the nanocomposite films obtained were also explored. POLYM. ENG. SCI., 59:E182–E194, 2019. © 2018 Society of Plastics Engineers     

一种新型胍类高分子型抗菌剂的制备及抗菌性能表征

本实验通过盐酸胍与马来酸酐合成抗菌功能化马来酸酐,再通过抗菌功能化马来酸酐与苯乙烯共聚的手段将抗菌功能化基团引入到高分子长链上,从而实现高效、光谱、稳定性高的抗菌作用。通过红外光谱测试手段确定了该共聚物含有酰胺基团,从而确定了胍类高分子抗菌剂的存在;通过抗菌实验对其抑菌效果进行研究,结果表明该胍类高分子型抗菌剂对大肠杆菌、白色念球菌、金黄色葡萄球菌具有较强的抗菌作用。     

Preparation of Silica Fillers for Stomatologic Composite Materials

Colloidal chemical processes in ethyl silicate gels and the crystallization of heat-treated silica are studied. The ethyl silicate/water ratio is shown to affect the optical properties of the filler. The effect of modifying additives on the refraction of light of heat-treated silica gel powders is studied. Controlled addition of Al₂O₃makes it possible to obtain powders with the required value of refraction index in the range of 1.490 – 1.510 to within 0.01.     

Preparation and Characterization of Natural Rubber Composites Comprising Conductive Carbon Black/Magnetite Hybrid Fillers Obtained by Impregnation Technology

Hybrid fillers have been prepared of conductive carbon black/magnetite at various ratios of the phases: 90:10, 70:30, and 50:50. The fillers have been characterized and their effect on the curing, mechanical, electric, and dynamic properties of natural rubber–based vulcanizates has been also investigated. The macrohomogeneity of the composites has been evaluated by ohmic resistivity measurements and correlation analysis. It has been established that all properties studied are dependent on the ratio between the filler’s phases. Viewing their composition, we conclude that the hybrid fillers are expected to exhibit both high dielectric and magnetic losses and may find application in the manufacturing of microwave absorbers.     

有机-无机复合抗菌剂的制备及抗菌性能

依次将无机抗菌离子(锌离子)和有机抗菌离子(十四烷基三丁基季鏻盐)插入到蒙脱土中制备出有机-无机复合抗菌剂,其中锌和季鏻盐的含量分别为2.60%(质量分数)和22.31%(质量分数)。热重(TG)、X-射线衍射(XRD)分析结果表明,锌离子和季鏻盐确实交换到蒙脱土中,并且复合抗菌剂中有机物的热分解起始温度为220℃左右,具有较好的热稳定性。抗菌试验的结果表明,复合抗菌剂具有较好的抗菌性能,对S.aereus和E.coli的最小抑菌浓度(MIC)分别为100μg.mL-1和300μg.mL-1。将100mg复合抗菌剂在100mL蒸馏水中浸20d后,季鏻盐阳离子和Zn2 的释放量均很小,分别为4.831mg.L-1和1.896mg.L-1,表明复合抗菌剂具有良好的耐水性。     

镀镍填料/甲基乙烯基硅橡胶导电复合材料的制备与性能研究

采用镀镍石墨(NCG)和镀镍碳纤维(NCF)并用填充甲基乙烯基硅橡胶(MVQ)制备导电复合材料,并对其导电性能、导电稳定性、硫化特性和物理性能进行研究。结果表明:与NCG/MVQ复合材料相比,NCG/NCF/MVQ复合材料能以较小填料用量达到相同的体积电阻率,且物理性能更好;NCG/NCF/MVQ复合材料的导电稳定性下降。     

PVDF粉末涂料中颜填料分散的表征方法

PVDF粉末涂料因其良好的耐候性能已成为氟碳涂料领域的一枚明珠,通过对成膜物、助剂以及颜填料的配比优化设计,不断地满足业界日益增长的高性能和高装饰性要求。本文从PVDF粉末涂料构建优化的角度出发,介绍了颜填料在复合材料体系中分散的表征方法,以此进一步提高对PVDF粉末涂料的工艺、结构与性能关系之间的认识。     

锌-铕抗菌材料的制备

通过溶胶-凝胶法制备出Zn-Eu抗菌白炭黑,该产品是一种含有稀土Eu3+的新型无机抗菌材料,与只单载Zn2+的抗菌白炭黑相比,该新型无机抗菌材料的抗菌性能更加显著.通过单因素实验探究Zn2+浓度、Eu3+浓度和反应时间对产品杀菌率的影响,得到最佳制备方案:Zn2+浓度为0.8 mol·L-1、Eu3+浓度0.005 mol·L-1、反应时间1 h.最佳条件下制备得到抗菌性能优良的Zn-Eu抗菌白炭黑,并对其进行FTIR、SEM和ICP-OES表征.FTIR结果显示,Zn2+和Eu3+加入后没有明显改变载体白炭黑的基本结构.SEM和ICP-OES分析表明,Zn-Eu抗菌白炭黑粒径较小,分散性较好并且Zn2+和Eu3+均担载在了载体白炭黑上.     

TiO2纳米晶/空心玻璃微珠复合填料的制备与研究

采用化学沉积法使TiO2以纳米粒子的形式包覆于空心玻璃微珠表面,成功制备了TiO2纳米晶/空心玻璃微珠复合填料.分别用扫描电镜(SEM)及紫外可见近红外分光光度计对产物进行了晶体形貌观察及光反射性能测试.结果表明:TiO2在空心玻璃微珠表面包覆效果良好,且经过热处理后空心玻璃微珠破损率很低,二氧化钛纳米晶尺寸为5～50 nm,膜层厚度为50～500 nm;光谱分析表明:该复合粉体对可见光和近红外波段的太阳光辐射具有很高的反射率(＞95%).将改性空心微珠、空心玻璃微珠及国外较好的玻璃微珠分别作为填料制备隔热涂料,光谱分析表明:以改性微珠作为填料制备的涂料,漆膜对太阳光主要能最波段(500～1500 nm)的光反射性能得到显著提高,当涂料与改性微珠质量比为100:15时,漆膜的光反射效果最佳,平均光反射率高于85%,该性能指标优于空心玻璃微珠及国外同类产品.     

Polyetherketones: Synthesis,Characterization and Antimicrobial Activity

ABSTRACT

Friedel-Crafts polyetherketones were prepared from o-chlorophenol, 1,4-phenylenedioxy diacetylchloride (1,4-PDC), chloroacetyl chloride (CAC), 1,2-dichloroethane (DCE), and dichloromethane (DCM) using anhydrous aluminium chloride (AlCl₃) as catalyst and carbon disulfide (CS₂) as solvent. These resins were characterized by IR spectroscopy and gel permeation chromatography. Carius method was employed to obtain the percentage of chlorine content in the resins. The kinetic parameters for the thermal behavior of the resins were evaluated from thermogravimetry (TG) using Broido method. Differential scanning calorimetry (DSC) thermograms of these resins were also obtained. All the polyetherketones were tested for their antimicrobial properties against bacteria, fungi, and yeast. It was observed that most of the polyetherketones synthesized could be used as antibacterial and antifungal agents.     

纳米二氧化硅的制备与表征

通过购买市售的几种不同生产厂家的纳米二氧化硅,分别对其做扫描电镜(SEM)分析、红外光谱(IR)分析和X射线衍射(XRD)分析,以了解纳米二氧化硅的表面及内部微观结构信息。分别用化学沉淀法和溶胶—凝胶法制备粒径在70 nm左右的二氧化硅粉末,并对两种方法的优缺点和制得的产品质量进行比较。改变反应物浓度、乙醇水体积比和表面活性剂的种类等条件,比较制得的二氧化硅粉末质量,以确定最优的制备方法。     

石墨烯的制备与表征

采用液相氧化法制备了氧化石墨,并通过水合肼还原氧化石墨制备了石墨烯。采用傅里叶变换红外光谱(FT-IR)、拉曼光谱(RS)、X-射线衍射(XRD)、热失重法(TG)等测试方法对石墨、氧化石墨和石墨烯的结构与耐热性进行了对比分析。研究结果表明,氧化石墨被水合肼还原成石墨烯后,氧化石墨的一部分sp3杂化碳原子被还原成石墨的sp2杂化碳原子,石墨烯sp2杂化碳层平面的平均尺寸比氧化石墨大,但结晶强度和规整度比石墨有所降低。在本实验条件下,氧化石墨的还原状态结构不可能被完全恢复到原有的石墨状态,也就是说石墨烯的结构和石墨结构还是有差别的。热分析结果表明,石墨烯具有比氧化石墨更为优异的热稳定性。     

石墨烯的制备与表征

本文先用Hummers法将天然鳞片石墨制备成氧化石墨,然后用超声波振荡30分钟,最后用联氨对其还原,制备出石墨烯。利用FT-IR、XRD、SEM等技术对石墨烯的结构、形貌进行了分析。试验结果表明:将石墨先氧化后还原法制备出的石墨烯具有无序的晶型、长厚比大。     

PDEGMA-b-POVNGA@AuNPs的制备及表征

以6-O-乙烯基己二酸-D-吡喃型半乳糖(OVNGA)和温敏性的二聚乙二醇单甲醚甲基丙烯酸甲酯(DEGMA)作为单体,采用酶促法、可逆加成-断裂链转移自由聚合法(RAFT)和"一锅法"联用,并与金纳米粒子(AuNPs)复合,制备了具有温敏性的含半乳糖基的PDEGMA-b-POVNGA@AuNPs复合物。通过1HNMR、FTIR和GPC对PDEGMA-b-POVNGA进行了结构表征,UV-Vis、TEM和DLS对AuNPs和PDEGMA-b-POVNGA@AuNPs进行了性能测试,变温UV-Vis对PDEGMA-b-POVNGA及PDEGMA-b-POVNGA@AuNPs复合物进行了温敏性考察。结果表明:PDEGMA-b-POVNGA@AuNPs复合物是由PDEGMA-b-POVNGA和AuNPs以S—Au键键合,将聚合物接枝到了AuNPs表面。PDEGMA-b-POVNGA的Mn和Mw分别为9.42×104和1.45×105。AuNPs平均粒径为25 nm。PDEGMA-b-POVNGA和PDEGMA-b-POVNGA@AuNPs的低临界温度(LCST)分别约为35.0和34.5℃。