GGC型高感乳剂沉降剂的研制

氨法乳剂在微粒高感中起着重要的作用,PA改性胶只能适用于中性法高感乳剂沉降。寻求适用于氨法乳剂制备时所用的改性明胶(GGC型)具有重要的意义。本文研究了多种改性明胶的合成。取代度的测定,沉降条件和复溶性能,沉降过程中明胶及卤化银的回收率以及改性明胶卤化银乳剂的感光性能等。研究结果表明,GGC型改性明胶具有以下的优点:取代度高。沉降诱发期短,沉降的pH范围窄,卤化银的回收率高。在用作氨法乳剂沉降剂时,GGC改性胶远比PA胶优异,表现在:耗酸量少和感光度高。     

改性明胶沉降剂的研制

沉降法在浓缩乳剂的制备中起着很重要的作用,改性明胶沉降剂的应用越来越被人们重视。本文研究了多种改性明胶的合成、取代度的测定、物理性能、沉降条件、沉降过程中明胶及卤化银的回收率和改性明胶卤化银乳剂的感光性能等。研究结果表明:改性明胶沉降剂具有以下的优点:取代度高、沉降诱发期短,沉降的pH范围较窄(一般0.6pH单位),卤化银的回收率高,而改性明胶沉降乳剂的性能比传统的水洗乳剂的性能优异:表现在灰雾小,最大密度高,分辨率好,感光度高和自然保存性能好。文章对造成上述现象的原因也进行了初步的分析和讨论。     

改性明胶沉降剂的等电点及其分布的研究

改性明胶已经被广泛地用作感光乳剂的沉降剂。然而对其沉降作用的机理,人们却还了解得很少。改性明胶的等电点,是影响改性明胶沉降的重要因素之一。我们采用等电聚焦的新技术,经过适当的改变,成功地测定了改性明胶的等电点及其分布。所得等电点分布的数值,能较好地说明改性胶为什么只有在确定的pH范围内才能进行沉降。     

甲酸盐在纳米AgBr/I粒子乳剂中的增感作用

分别以鱼明胶和骨明胶(惰胶)作为分散介质制备了两种不同形貌与粒径的纳米AgBr/I粒子乳剂.利用掺入作为正空穴捕获剂的甲酸盐,可以使本征感光度很低的纳米粒子乳剂的感光度有相当大的提高,显示甲酸盐具有很好的增感效果.对鱼明胶介质中制备的纳米AgBr/I粒子乳剂,甲酸盐掺杂方式不同其增感效果不一样.在乳剂颗粒中均匀掺杂增感效果最好,而趋向于近表面掺杂则增感效果降低,显示出甲酸盐掺杂的位置效应.籽晶掺杂后包壳的复合结构乳剂颗粒与均匀掺杂乳剂颗粒的增感效果近似.对鱼明胶介质中制备的掺杂甲酸盐的纳米AgBr/I粒子乳剂再进行硫增感或硫加金增感,乳剂感光度可进一步提高,表明甲酸盐掺杂与常规的硫增感或硫加金增感有很好的协同作用.     

超高感彩卷乳剂微晶体电镜研究

应用物理和化学相结合的方法，将超高感彩卷分层剥离，离心沉降，水洗除胶，电镜观测各层乳剂的微晶体结构。揭示了超高感彩卷各乳剂层的结构情况，披露了超高感彩剂制造技术。     

纳米级Ag2S增感剂的制备及立方体和{100}面扁平氯化银影像体系的化学增感研究

由于氯化银{100}面扁平微晶乳剂的一系列优点及其巨大的发展潜力,使它备受当代影像科学研究人员的广泛关注.但研究者也一直被该乳剂在化学增感时总是伴随高灰雾的难题长期困扰.在明胶水溶液的保护下制备了粒径5nm的Ag2S纳米颗粒,并通过感光性能研究发现:该颗粒用作化学增感剂对氯化银立方体和{100}面扁平乳剂增感时,比传统使用的Na2S2O3增感剂优越,在低灰雾水平下获得了较高感光度,很好地解决了上述氯化银{100}面扁平微晶乳剂增感的难题.用漫反射光谱(DRS)作探针,跟踪记录纳米结构Ag2S增感剂加入后氯化银晶体表面上纳米Ag2S增感剂颗粒的演变情况,为新型纳米增感剂的优异增感特性提供了机理性解释.     

鱼明胶作为卤化银纳米粒子载体的研究

采用的鱼明胶样品是从深海鱼的鱼皮提取而得,在成份和物理性质方面鱼明胶与通常使用的动物明胶有显著的差别.研究表明,鱼明胶的蛋白成分中α组分占绝对优势,且其中分子量较小的α2组分又比分子量较大的α1组分含量高得多.在鱼明胶中几乎没有分子量最大的γ组分.其氨基酸残基中,脯氨酸和羟脯氨酸的含量比动物胶低,而蛋氨酸含量却明显高于后者.鱼明胶还具有较低的胶凝温度.这些特点可能使之适宜作为分散介质来制备AgBrI纳米粒子乳剂.此外,鱼明胶中含有较多含硫物质,而且杂质铁主要以三价形式存在.并且进一步利用鱼明胶作为保护载体,在广泛的胶银比(即明胶量与银量之比值)范围(从8∶ 1到4∶ 1)获得了平均粒径为14 nm的 AgBrI纳米粒子乳剂.该乳剂具有良好的单分散性和热稳定性.对纳米粒子乳剂进行硫-金协同敏化可以提高其感光度.若适当增加敏化剂用量和适当延长敏化时间这种协同敏化作用的效果更好.     

氯化银立方体微晶乳剂和{100}面扁平微晶乳剂的甲酸盐掺杂增感

将甲酸盐掺杂在乳剂微晶不同位置处,制备成氯化银立方体微晶乳剂和{100}面扁平微晶乳剂.实验发现:作为正空穴捕获剂,适当计量的甲酸盐在不增加乳剂灰雾的前提下,可使上述乳剂的感光度提升3—8倍.甲酸盐在两种晶形乳剂的不同位置掺杂的研究结果显示,甲酸盐均匀掺杂可比表面掺杂获得更高的感光度.在两种乳剂中甲酸盐掺杂增感都可与其后的硫增感、硫加金增感以及光谱增感协同作用,进一步提升乳剂的感光性能.     

纳米级Ag2S增感剂的制备及立方体和{100}面扁平氯化银影像体系的化学增感研究

由于氯化银{100}面扁平微晶乳剂的一系列优点及其巨大的发展潜力, 使它备受当代影像科学研究人员的广泛关注. 但研究者也一直被该乳剂在化学增感时总是伴随高灰雾的难题长期困扰. 在明胶水溶液的保护下制备了粒径 5 nm的Ag₂S纳米颗粒, 并通过感光性能研究发现: 该颗粒用作化学增感剂对氯化银立方体和{100}面扁平乳剂增感时, 比传统使用的Na₂S₂O₃增感剂优越, 在低灰雾水平下获得了较高感光度, 很好地解决了上述氯化银{100}面扁平微晶乳剂增感的难题. 用漫反射光谱(DRS)作探针, 跟踪记录纳米结构Ag₂S增感剂加入后氯化银晶体表面上纳米Ag₂S增感剂颗粒的演变情况, 为新型纳米增感剂的优异增感特性提供了机理性解释.     

明胶中蛋氨酸含量对氯化银{100}面T-颗粒乳剂晶形的影响

氯化银{100}面T 颗粒乳剂是一种新型感光乳剂,近年来受到感光界广泛关注.本文着重讨论了明胶中蛋氨酸含量对该种乳剂生成过程的影响.实验发现,明胶中蛋氨酸含量对乳剂微晶的晶体形态和形成一定晶形的乳化时间的长短有直接影响,并推断这一作用与蛋氨酸对颗粒表面Ag⁺的吸附密切相关.     

SYNTHESIS OF ALKYL- AND ARYLPHOSPHONIC ACID MONOESTERS BY DIRECT ESTERIFICATION OF DIBASIC PHOSPHONIC ACIDS IN THE PRESENCE OF AN ARSONIC ACID CATALYST

Partial hydrolysis of a diester, hydrolysis of the monochloro monoester, or alcoholysis of a phosphonic acid anhydride generally is used to prepare monoesters of alkyl- and arylphosphonic acids. Limited cases have been reported for the esterification of a dibasic phosphonic acid to yield the monoester, and none of these methods are as simple as the analogous method for preparing carboxylic acid esters, in which the carboxylic acid is esterified with an alcohol in the presence of an acid catalyst. Described is a method for preparing monoesters of alkyl- and arylphosphonic acids by direct esterification with an alcohol in the presence of a catalytic amount of phenylarsonic acid. The water formed during the reaction is removed azeotropically. For example, methylphosphonic acid was esterified in good yield to give its isopropyl, butyl, cyclohexyl, bornyl, and octadecyl monoesters. Similarly prepared are the ethyl, butyl, hexyl, and 2-(ethylthio)ethyl monoesters of phenylphosphonic acid, as well as 2-isopropoxyethyl hydrogen ethylphosphonate and 2-methoxyethyl hydrogen benzylphosphonate.     

不同类型的明胶对DCG全息图的衍射效率影响的研究

本文对几种不同类型的明胶对DCG全息图的衍射效率的影响进行了研究。发现不同类型的明胶对DCG全息图的衍射效率的影响差异较大。活性胶,最高衍射效率可达80%以上,全息图的透明度很好;改性胶,衍射效率在60～80%之间,全息图上易产生“白雾”;惰性明胶,虽可得到透明清晰的全息图,但最高衍射效率一般不超过50%.     

Syntheses and Characterization of Polymetallosiloxanes from Silicic Acid and Metal Chlorides

Syntheses and characterization of polymetallosiloxanes by the non-hydrolysis sol-gel process using no metal alkoxides were investigated. The reaction of silicic acid (SA) with MCl₄ (M = Ti, Zr) in the molar ratios SA/MCl₄ = 0.5–3.0 using a tetrahydrofuran-methanol solvent formed polymetallosiloxane (PMS), which was insoluble in organic solvents regardless of the molar ratio. The PMS was isolated as esterified polymetallosiloxane by esterification with isopropyl alcohol for various periods, which were soluble in methanol, acetone, and tetrahydrofuran. The number average molecular weight was 1000–3200 for esterified polytitanosiloxane and 3400–11000 for esterified polyzirconosiloxane. Esterified polymetallosiloxanes had no melting point but decomposition point. The results of analytical data indicated that esterified polymetallosiloxane and/or polymetallosiloxane consisted of the main chain of Si–O–Si and Si–O–M linkage with the pendants of alkoxy, silanol, and chloro group.     

INFLUENCE OF MOLECULAR STRUCTURES OF SECONDARY AMINE TERMINATED POLY（ESTER-AMINE）S ON THE CURING PERFORMANCE WITH EPOXY RESIN

Five secondary amine terminated poly(ester-amine)s(defined as PEA)with controlled molecular structures were synthesized through reacting excessive piperazine with phthalicdiglycol diacrylate(PDDA)and 1,1,1-trimethylolpropane triacrylate(TMPTA)at a constant secondary amine/acrylate group ratio of 1.5/1 and at different PDDA/TMPTA molar ratios. Both IR and ~(?)H-NMR spectra indicated that all acrylate groups were consumed in the reaction,based on which the structural parameters were calculated from the ~(?)H-NMR spectra.With decreasing PDDA/TMPTA ratio,the content of secondary amine,degree of branching,molecular weight,T_g and T_d increased accordingly.These polymers were further used as both crosslinkers and flexibilizers for a linear epoxy resin E51 to form cured films under ambient condition.The gel content, relative hardness and T_g of the resulting films increased as PEA molecules changed from linear to highly branching structures.Due to the flexibility of PEA molecules,all the films possessed excellent mechanical performance.     

Emission from charge recombination during the pulse radiolysis of 9-cyano-10-phenylethynylanthracenes with donor and acceptor substituents

Emission from 9-cyano-10-phenylanthracene and 9-cyano-10-phenylethynylanthracenes having donor and acceptor substituents (RA = PA, PEA, OEA, NEA, and DEA) was studied with the time-resolved fluorescence measurement during the pulse radiolysis of RAs in benzene (Bz). PA and DEA showed only monomer emission, while other RAs (PEA, OEA, and NEA) showed both monomer and excimer emissions with much lower intensities. On the basis of the steady-state and transient absorption and emission measurements, the formation of RA in the singlet excited state ((1)RA*) can be attributed to the charge recombination between RA radical cation and anion (RA*+ and RA*-, respectively) which are initially generated from the radiolytic reaction in Bz. It is expected that for PA with a twisted geometry, the charge recombination between PA*+ and PA*- occurs to give (1)PA* during the pulse radiolysis in Bz. For PEA and OEA, pi-stacking interaction is possible for the formation of an encounter complex during the charge recombination between RA*+ and RA*-. For NEA, it is expected that NEA*+ and NEA*- collide neck-to-neck to generate the excimer due to the twisted geometry. For DEA, a considerably twisted structure is assumed to give (1)DEA* with strong ICT character but not (1)(DEA)2* because of the bulky donor substituent.     

Structural and thermal characterization of sugarcane bagasse phthalates prepared with ultrasound irradiation

Chemical modification of sugarcane bagasse was achieved by esterification with phthalic anhydride in pyridine after ultrasound irradiation. The parameters including ultrasonic irradiation time 0-40 min, phthalic anhydride dosage 2.5-7.5 g, reaction time 30-150 min, and reaction temperature 80-115 °C were optimised and the extent of phthalation was measured by weight percent gain. It was found that degradation of the cell wall polymers occurred at higher temperature (>90 °C) under the experimental conditions used.FT-IR and CP/MAS ¹³C NMR spectroscopy studies also clearly produced evidence for phthalation reaction. The phthalated bagasse preparations showed decreased thermal stability after chemical modification.     

甲壳胺-明胶共混物的研究

甲壳胺 明胶共混物的研究莫秀梅（华东理工大学高分子材料系上海２００２３７）关键词甲壳素，明胶，共混物，红外光谱甲壳胺是甲壳素的脱乙酰基产物，即将甲壳素Ｃ２上的乙酰基脱去变成氨基，因此在甲壳胺分子侧链上增加了一个活泼氨基，从而易于化学改性或共混改性．...     

化学改性对木材热塑性能的影响

在非有机溶剂体系中对木粉进行酯化和接枝处理,能够降低纤维素结晶度,破坏木素的化学结合,处理后的木粉的热软化温度比未处理木粉低,虽然不能完全塑化,但在160℃的温度下热压成型可以得到表面光滑,红褐色的半透明压片,表面化学处理已赋予木材一定的热压加工性能。     

某些助剂对明胶的凝胶强度的影响的研究

众所周知,物理力学性能是照相明胶的一种很重要的属性。在各种彩色及黑白胶片都面向高温快速加工发展的今天,这种属性就显得更为重要。提高胶片的物理力学性能,一方面要从提高明胶本身的胶冻强度着手,例如减少明胶中溶胶组份(分子量小、冷水中溶解度高),提高明胶中的α和β组份的相对含量,减少分子量过大的组份等等。