亲水拒油含氟整理剂的合成及其在棉织物上的应用

以F113和全氟聚醚酰氟为原料,合成了全氟聚醚二酰基过氧化物,并用来引发二甲基二烯丙基氯化铵聚合,得到含有全氟烷氧基(末端基团)的二甲基二烯丙基氯化铵聚合物Pf通过传统的轧-烘-焙过程将其整理到棉织物上.通过测试水和正十二烷在整理后织物上的接触角对该聚合物的亲水拒油性能进行评价.结果表明:聚合物Pf具有良好的亲水拒油性,对水的接触角为0°,对正十二烷的接触角为116.3°,同时整理后的棉织物具有很好的亲水拒油耐洗性.     

乌梅提取液对大肠杆菌的抑菌特性研究

为研究乌梅提取液对大肠杆菌的抑制特性,该文对不同浓度提取液、培养基pH值、热处理、环境离子浓度及暴露时间对提取液抑菌活性的影响进行了研究。结果表明:最低抑菌浓度为12.5 mg/mL,在酸性条件下提取液具有较高的抑菌活性,提取液对温度较为稳定,适用于采用巴氏杀菌的食品当中,乌梅提取液对钠离子适应性好,而钙离子可显著降低其抑菌活性,提取液在短时间内(4 d)暴露于空气中对其抑菌活性影响较小,但长时间仍然会显著降低其抑菌活性。研究结果表明乌梅提取液对大肠杆菌具有较好的抑菌效果,受环境条件影响较小,为乌梅天然食品防腐剂的开发提供了理论基础。     

紫米酒发酵工艺条件的研究

以紫米为原料进行米酒发酵。通过单因素实验确定原料配比、加曲量、发酵温度及发酵时间的单因素最佳值;然后利用单变量多因素方差分析探索其对发酵的影响;再通过探索性因子分析考察总糖、还原糖、总酸及净出汁量与紫米酒发酵间的关系。结果表明:单因素最佳值为紫糯比1∶3,加曲量0.8%,发酵温度30℃,发酵时间48 h;发酵时间及加曲量对紫米酒发酵的影响最大,三者的影响顺序为:发酵时间>加曲量>发酵温度;酸类及糖类因子与紫米酒发酵的关系非常密切,而它们对紫米酒发酵的贡献方式也各不一样。总酸及糖类物质的变化对发酵的影响非常大。     

HACCP在食盐生产中的应用

随着人们生活水平的提高,食品的安全卫生状况成为消费者关注的焦点。食盐是一种非常重要的食品原料,作为中间环节的食品生产者,则理应对食品安全负有主要责任。HACCP作为预防潜在危害、控制食品安全的经济而有效的管理体系,在食盐生产行业中推行,具有十分重要的意义。     

超临界CO2萃取疯树籽油工艺的响应面优化

采用超临界CO2流体技术对麻疯树籽油进行萃取,运用响应面法优化了萃取工艺条件。结果表明,超临界CO2萃取麻疯树籽油的最佳工艺条件为:原料粒度20目,萃取压力37 MPa,萃取温度44.5℃,CO2流速30 L/h,萃取时间120 min,夹带剂(95%乙醇)用量为原料质量的40%,在此条件下,麻疯树籽油提取率可达93.13%。将超临界CO2萃取的麻疯树籽油与螺旋压榨法提取的麻疯树籽油品质进行分析比较,结果显示超临界CO2萃取法得到的麻疯树籽油品质优于螺旋压榨法。     

羊毛低温染色助剂应用性能及作用机制

研究了LDW-630羊毛低温染色助剂的应用性能,并对其作用机理进行了探讨。结果表明,应用低温染色助剂可以使羊毛织物在80～85℃下染得常规染色的表观色深度,染色牢度达到常规染色的牢度等级,染透性达到常规染色水平,染色后羊毛单纤维断裂强力和伸长比常规染色工艺有明显提高。促染作用机理研究结果表明,LDW-630羊毛低温染色助剂能促进染料的溶解和分散。红外光谱分析结果表明,LDW-630羊毛低温染色助剂能在染色过程中打开羊毛纤维中的二硫键生成巯基和硫氧化合物,巯基在羊毛纤维暴露于空气中时部分氧化回二硫键状态,保证羊毛强力,提升染色牢度。     

Optimization of room-temperature TCR of polycrystalline La0.9-xSrxK0.1MnO3 ceramics by Sr adjustment

High-density La_0.9-xSr_xK_0.1MnO₃ ceramics (LSKMO, A-site = La, Sr and K, 0 ≤ x ≤ 0.25) are successfully fabricated by using facile sol-gel method. Electrical properties are performed by using combination of phenomenological percolation (PP) model, double exchange (DE) mechanism, and Jahn-Teller (JT) effect. Moreover, X-ray diffraction and scanning electron microscopy are employed to analyze the structure and morphology of LSKMO ceramics. Valence states and ionic stoichiometry are assessed by using X-ray photoemission spectrometry. Results reveal that Sr²⁺ ions, substituting La³⁺ ions, significantly influenced DE mechanism and JT effect. In addition, Sr-doping plays essential role in improving electrical properties of LSKMO ceramics. At optimal doping content of x = 0.09, peak temperature coefficient of resistance (TCR) of the resistivity is found to be 11.56% K^?1 at 297.15 K, which is optimal TCR for A-site K-occupied perovskite manganese oxides. These results confirm that polycrystalline LSKMO ceramics render high room-temperature TCR values due to Sr-doping.     

Fabrication and Characterization of Highly Oriented Composite Nanofibers with Excellent Mechanical Strength and Thermal Stability

Here, highly‐oriented poly(m‐phenylene isophthalamide)/polyacrylonitrile multi‐walled carbon nanotube (PMIA/PAN‐MWCNT) composite nanofiber membranes with excellent mechanical strength and thermal stability are successfully produced using electrospinning. It is demonstrated that the cooperation of multi‐walled carbon nanotubes (MWCNT) and high‐speed rotating collection is beneficial to the acquisition of highly oriented fibers and effectively improves the mechanical strength of the membrane along the orientation direction. Specifically, the tensile stress of poly(m‐phenylene isophthalamide)/polyacrylonitrile (PMIA/PAN) membrane is enhanced significantly from 10.6 to 20.7 MPa, benefiting from the highly oriented alignment of the fibers as well as the reinforcing effect of MWCNTs on the fibers. Furthermore, the stressing process of single fiber and fiber aggregates is carefully simulated, and the influence of MWCNTs on the mechanical properties of PMIA/PAN‐MWCNT membranes is analyzed comprehensively, providing a meaningful auxiliary means for the study of mechanical properties. In addition, the composite nanofiber membrane has the advantages of both PMIA and PAN, possessing high temperature resistance, flame‐retardancy, and chemical stability, for an ideal high‐temperature material. In short, the as‐prepared PMIA/PAN‐MWCNT composite membrane with excellent comprehensive property emerges a promising application in many fields, especially in high‐tech.     

Preparation of Aqueous Nanodispersions of Disperse Dye by High-Gravity Technology and Spray Drying

Disperse dyes are poorly water-soluble and difficult to stably disperse in an aqueous medium, which greatly limits their application in dyeing synthetic fibers. Micronization can solve this problem. Herein, a facile way to prepare stable aqueous nanodispersions of disperse dye (C.I. disperse yellow 54) is presented by combining high-gravity antisolvent precipitation in a rotating packed bed (RPB) with spray drying. The as-prepared product had an average particle size of 120 nm, which could be readily redispersed in water. Compared with raw dye, the wettability and dispersibility of disperse dye nanoparticles were remarkably improved. Furthermore, the dyeing properties of the nanodispersions were obviously better than those of the commercial dye, which was micronized by ball milling.