明胶和苯甲醛对半光亮酸性锡电沉积的影响

目前,国内外鲜见对半光亮酸性镀锡添加剂的研究报道.采用SEM及稳态极化曲线研究了明胶和苯甲醛对半光亮酸性锡沉积层形貌及阴极极化的影响.结果表明:苯甲醛和明胶对沉积层形貌、晶粒大小及致密性均具有显著影响,不加苯甲醛和明胶或加入量太少时,镀层晶粒粗大,呈层状生长;随着加入量增大,晶粒尺寸显著细化,呈块状生长;当加入量过大时...     

烟煤胶质层指数准确度的试验

介绍了烟煤胶质层指数的测定方法,分析了煤样粒度、装样量、升温速度等对烟煤胶质层指数测定的影响,对传统法与半自动法的胶质层指数测定准确度进行了试验,该试验结果准确,能满足邯钢焦化厂的生产需要。     

明胶/淀粉/聚乙烯醇复合肥料包膜的结构与性能

以明胶、淀粉和聚乙烯醇为原料,在交联剂戊二醛和增塑剂甘油存在下,用溶液共混法制备了明胶复合肥料膜.采用红外光谱(FT IR)、X-射线衍射、扫描电镜等表征了复合膜的结构,同时测试了膜的拉伸强度、断裂伸长率、耐水性和尿素的释放率.结果表明,原料之间产生了较强的相互作用,形成了一个较稳定的复合体,复合膜具有良好的力学性能和...     

苄叉丙酮和明胶对酸性镀锡层的影响

采用SEM,XRD和赫尔槽等方法研究了苄叉丙酮和明胶对酸性镀锡层形貌、沉积速率和分散能力的影响。当苄叉丙酮的质量浓度较低时,镀层微粒呈柱状,结晶大小极不均匀。随着其质量浓度的增大,镀层形貌向片状转变,且晶粒尺寸显著细化。当明胶的质量浓度较低时,镀层微粒呈片状紧密地吸附在基体表面,导致结晶不太均匀。随着其质量浓度的增大,镀层晶粒进一步细化均匀。随着苄叉丙酮和明胶的质量浓度的增大,镀层沉积速率先增大后减小,适宜的苄叉丙酮和明胶的质量浓度分别为0.01 g/L和1 g/L。在适宜的条件下施镀15 min,所得镀层在(112)晶面择优取向,结晶细致均匀、光滑平整,为半光亮,镀层沉积速率和镀液分散能力分别达到4 341 mg/(dm2.h)和98.08%,可用于印刷线路板酸性镀锡。     

酸性脲酶的固定化研究

以明胶为包埋材料,戊二醛为交联剂固定化粪产碱菌所产的酸性脲酶。对酸性脲酶的固定化条件(包括明胶含量、戊二醛浓度、吸附时间、交联时间和粗酶液用量)及酶学性质(温度和pH值)进行了研究。结果表明,固定化酶的最适宜条件为：明胶的质量分数15％,戊二醛质量分数0.3％,吸附时间4 h,交联时间20 min,粗酶液用量4 mL。...     

γ-（2,3环氧丙氧）丙基三甲氧基硅烷改性海藻酸钠和明胶渗透蒸发杂化膜的制备及乙酸脱水性能研究

通过硅烷偶联剂对海藻酸钠-明胶共混膜进行交联改性制备乙酸脱水渗透蒸发杂化膜。实验结果表明：随着偶联剂含量的增加,杂化膜的对水的选择性先增加后下降,在3 wt%时有最好的选择性,同时膜的渗透通量随着偶联剂含量增加而增大;膜的选择性随着进料乙酸浓度增大而增大,通量随着进料乙酸浓度增大而减少。     

明胶作分散剂制备球形超细银粉

采用化学还原法,以抗坏血酸为还原剂,明胶为分散剂制备了球形超细银粉。探讨了反应过程中AgNO3溶液浓度、反应液pH值、明胶用量、试剂滴加顺序等因素对银粉粒度大小及分布的影响。在pH为7时,将0.5 mol/L的AgNO3溶液加入到0.25 mol/L的抗坏血酸溶液中,明胶用量为AgNO3质量的1.5%,且在产生沉淀后逐滴加入能制备出大小1.5 μm左右,粒度分布均匀的球形超细银粉。     

Optimization of Hydrolysis Conditions for the Production of Antioxidant Peptides from Fish Gelatin Using Response Surface Methodology

Abstract: Fish skin gelatin was hydrolyzed with papain to produce antioxidant peptides. Response surface methodology (RSM) was applied to optimize the hydrolysis conditions (including enzyme to substrate ratio [E/S], hydrolysis time, and temperature). The highest degree of hydrolysis (DH) (50.1 ± 1.1%) was obtained at an E/S of 2% at 56.8 °C, 2.11 h, and was not significantly different from the predicted values within a 95% confidence interval. The highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) (96.8 ± 0.9%) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS^•+) (9.80 ± 0.11 mM Trolox [6-hydroxy-2,5,7,8-tetramethychroman-2-carboxylic acid]) radical-scavenging activities of fish gelatin hydrolyzates were obtained at an E/S of 3% at 52.1 °C, 2.65 h, and both DPPH and ABTS^•+ radical-scavenging activities were not significantly different from the predicted values 97.3% and 9.86 mM Trolox within the 95% confidence interval. Therefore, RSM is an efficient way to optimize fish gelatin hydrolysation and the resultant hydrolyzates show promise as antioxidant peptides. Practical Application: There is a growing interest in the use of fish gelatin as an alternative to mammalian gelatin. One potential use is as a source of widely acceptable functional compounds. In this study, a search for antioxidant peptides from fish gelatin prepared by an enzymatic method has been successfully done. This suggests that this is a practical way to obtain bioactive peptides.     

Preparation and functional properties of fish gelatin–chitosan blend edible films

With the goal of improving the physico-chemical performance of fish gelatin-based films, composite films were prepared with increasing concentrations of chitosan (Ch) (100G:0Ch, 80G:20Ch, 70G:30Ch, 60G:40Ch and 0G:100Ch, gelatin:Ch), and some of their main physical and functional properties were characterised. The results indicated that the addition of Ch caused significant increase (p < 0.05) in the tensile strength (TS) and elastic modulus, leading to stronger films as compared with gelatin film, but significantly (p < 0.05) decreased the elongation at break. Ch drastically reduced the water vapour permeability (WVP) and solubility of gelatin films, as this decline for the blend film with a 60:40 ratio has been of about 50% (p < 0.05). The light barrier measurements present low values of transparency at 600 nm of the gelatin–chitosan films, indicating that films are very transparent while they have excellent barrier properties against UV light. The structural properties investigated by FTIR and DSC showed a clear interaction between fish gelatin and Ch, forming a new material with enhanced mechanical properties.     

Effect of clay content, homogenization RPM, pH, and ultrasonication on mechanical and barrier properties of fish gelatin/montmorillonite nanocomposite films

The effect of clay content, homogenization RPM, and pH on the mechanical and barrier properties of fish gelatin/nanoclay composite films was investigated. The addition of 5% nanoclay (w/w) increased the tensile strength from 30.31 ± 2.37 MPa to 40.71 ± 3.30 MPa. The 9 g clay/100 g gelatin film exhibited the largest improvements in oxygen and water barrier properties. Oxygen permeability decreased from 402.8 × 10⁻⁶ ± 0.7 × 10⁻⁶ g m/m² day atm to 114.4 × 10⁻⁶ ± 16.2 × 10⁻⁶ g m/m² day atm and the water vapor permeability decreased from 31.2 × 10⁻³ ± 1.6 × 10⁻³ ng m/m² s Pa to 8.1 × 10⁻³ ± 0.1 × 10⁻³ ng m/m² s Pa. The XRD and TEM observation suggested that the ultrasonication treatment (30 min at 40% output) resulted in exfoliation of the silicates.