Search results

This study aims to synthesize Prussian blue {Fe^III₄[Fe^II(CN)₆]₃} pigment by reacting ferric chloride with different ferrocyanides through the same procedure. The influence of the ferrocyanide used on resulting pigment properties is studied.

Prussian blue is commonly synthesized by direct or indirect methods, through iron salt and ferrocyanide/ferricyanide reactions. In this study, the direct, single-step process was pursued by dropwise addition of the ferrocyanide into ferric chloride (both as aqueous solutions). Two batches – (K-PB) and (Na-PB) – were prepared by using potassium ferrocyanide and sodium ferrocyanide, respectively. The development of pigment was confirmed by an identification test and characterized by spectroscopic techniques. Pigment properties were determined, and light fastness was observed for acrylic emulsion films incorporating dispersed pigment.

The two pigments differed mainly in elemental detection owing to the dissimilar ferrocyanide being used; IR spectroscopy where only (Na-PB) showed peaks indicating water molecules; and bleeding tendency where (K-PB) was water soluble whereas (Na-PB) was not. The pigment exhibited remarkable blue colour and good bleeding resistance in several solvents and showed no fading in 24 h of light exposure though oil absorption values were high.

This article is a comparative study of Prussian blue pigment properties obtained using different ferrocyanides. The dissimilarity in the extent of water solubility will influence potential applications as a colourant in paints and inks. K-PB would be advantageous in aqueous formulations to confer a blue colour without any dispersing aid but unfavourable in systems where other coats are water-based due to their bleeding tendency.

Deed of Partnership 1766 ........ do covenant and agree with each other to be in partnership for the full term of 7 years to commence from this date hereof—to do our utmost to make a certain blue colour for paints a secret only known to Mr. Fredk. Rapp and Mr. Louis Steigenberger, in consideration of which Mr. John Stalder is to allow a room wherever we all dwell, and work for their colours, to keep the colours and other materials in. And the said Mr. John Stalder must not want to come into said room, nor at any time obstruct his two partners, nor give abusive language by reason of his not being made acquainted with the secret of making said blue for paint and not be allowed to know the cost of the stuff.

The first applications for blue pigments are clothed in antiquity and various shades were used in early cave drawings. There has always tended to be a demand for blue pigments and they have had an extensive range of uses from early times.

The purpose of this paper is to provide an investigation on a new kind of adsorbent materials, namely, the Prussian blue analog (PBA)-loaded albite-base porous ceramic foam, which can effectively adsorb the heavy metal ion in the wastewater.

The natural zeolite powder has been used as the primary raw material to make a sort of porous ceramic foam by impregnating polymer foam in slurry and then sintering. Adjusting the technological parameters could control the bulk density of the ceramic product, which could float on water with the bulk density less than 1 g/cm³ and also sink in water with the bulk density higher than 1 g/cm³. After desilicating the porous ceramic foam, an Al-Fe type PBA with a strong function of ion exchange was loaded on the ceramic surface by directly yielding.

The adsorption performance for harmful metal ions was greatly improved by combining together the high adsorption capability of the PB analog and the efficient high specific surface area of the porous ceramic foam.

This work presents a PBA-loaded albite-base porous ceramic foam that can effectively adsorb the harmful substance in water, and the adsorption efficiency for some typical harmful ions, i.e., Cd²⁺, Cs⁺ and As(V), was examined under different conditions of the experimental period, the pH value and the ion concentration in the tested solution.

Manox Ltd, an RTZ Chemicals company, states that it is to proceed with the modernisation and expansion of its plant for the manufacture of prussian blue. This decision is said to be in line with the company's policy to consolidate an develop its central activity at Miles Platting in the production of iron blues, pigment raw materials and related ferrocyanide products.

One of the most important functions of the green pigments over the centuries has been to reflect in paintwork the abundance of the colour in nature. Also because of this association, parts of buildings, including doors, have been painted green so that they would blend more readily with the surrounding lawns and trees. Green pigments were probably used far more extensively in the pre‐war periods for this purpose than they are today, primarily because of the conservative nature of the shades produced at the time which reflected more readily the mood of that period. Since then, however, their use in building application has tended to wane a little, because of the wider range of colours now used. More exciting shades are continually being produced now and the colour is quite extensively used in a much wider range of applications than previously.

Industrial cellulose nitrate, sometimes called pyroxylin, collodion cotton or nitrocotton, is made by treating cellulose in the form of cotton (inters (threads) or woodpulp with a large excess of mixed nitric and sulphuric acid controlled to fine limits as regards strength of acid and the time and temperature of the nitration. Following a water washing process, the nitrocellulose is partially dried and the remaining water displaced by the selected damping medium — industrial methylated spirit, isopropanol or butanol. For certain purposes the nitrocellulose is damped with water.

The purpose of this paper is to identify different automotive coatings using Confocal Raman microscope which could hardly be differentiated with Fourier transform infrared microscope (FTIR).

Raman spectroscopy was used to provide extra vibration information to infrared spectroscopy. Paints preparation was not necessary, and only 30 s was needed for each sample in an optimised method. Paints were first analysed by FTIR and then compared with Raman microscope.

Raman microscope was used to address the lack of ability of FTIR in discriminating four groups of paints in same colours. This study indicated that Raman microscopy is especially effective in sensing pigments and could successfully identify all pigments in the paints.

The two instruments in combination produce accurate results than when used individually, especially in complex and multi-layered paints analysis.

The method proved to be fast, accurate and non-destructive, and it could be easily applied to real cases.

With this method, scientists could discriminate some coating types which were hard to be discriminated by other techniques.

In the days of our childhood we were told that the process of picking tea in China involved a preliminary purificatory ritual on the part of the picker. Thus, he ate no fish, indulged in baths, and dressed himself in clean clothes as essential preliminaries before pursuing his occupation. This may have been true so far as the tea that was to be consumed by the Chinese went. So far as this country was concerned, it is on record that somewhere about the year of grace 1850 the ingenious Celestial was sending us consignments alleged to contain silkworm‐dung faced with tea‐dust and a little Prussian blue, sand, and gum, and so forth, a decoction of this being drunk by certain inhabitants of this happy land under the firm belief that they were partaking of the “cup that cheers but not inebriates.” Such frauds were possible, as at that time but little attention had been paid to the subject of food chemistry, and no attention at all to the kind of food that was being eaten by the people of London and elsewhere. The subject of food was chiefly dealt with from the point of view of the requirements of the inland revenue, and so long as the Government obtained the duty that was demanded, but little heed was paid to the quality of the product taxed. Very recently we have had arriving at the docks a carge of foods from Hankow, China, consisting largely of frozen pigs. We are assured that these redoubtable porkers have been fed on rice, and while alive have been carefully tended. It is not stated that they were fed from golden troughs, or that they were slaughtered by, say, members of the Chinese aristocracy, but it is stated and assumed that they are all that any self‐respecting Englishman can possibly desire. A point in their favour is also made of the cheapness of the pork yielded by them. At the present time our food is nothing if not cheap, and “cheap food” has become a party cry whose success depends on the obsession of the minds of a large number of ill‐informed persons with the idea that the only attribute of a food which is worthy of consideration is its cheapness. The fact that we are receiving foodstuffs of the nature of meat from China is one that demands special and more serious consideration from the authorities in view of its possible prejudicial influence on public health, and the important changes that may take place in the nature and origin of our meat supplies. The consignment in question consists of game of various kinds, eggs, ducks, and pork. About 4,600 frozen pig carcases were unloaded. It is asserted that the pigs were fed on rice, or at all events on clean food, and there seem no grounds for disbelieving the truth of this statement; but the increase in this trade which is looked for from those financially interested in it does not necessarily mean that the goodness of future consignments is assured. The fact that the trade may greatly develop makes it difficult to see how a proper supervision can be maintained over the Chinese farmers who will presumably furnish the material of future consignments. Inspection in China is, however, imperatively demanded in the interests of public health on this side. Only a small proportion of the consignment we refer to has been put on the market up to the present, and this was subjected to a very careful and thorough inspection at this end before it was put on the market. The process of inspecting every carcase that may be landed is one that from the mere amount of time and labour involved presents serious difficulties, and the thawing process necessarily leads to a certain amount of deterioration. But if the trade in Chinese pork increases, and the resources of China to supply pigs to the world's markets are practically illimitable, we do not see how it will be possible to adequately inspect every consignment that comes across, while on the other hand no country requires more careful looking after than China in this respect. Inspection on the other side must apparently be left in the hands of the exporters, a most undesirable course to adopt, and one that should therefore not be encouraged. It need hardly be pointed out that the Chinese authorities can or will do nothing in the matter. For a system of inspection to be thorough and adequate, and such inspection is absolutely necessary in this case, it is needful to have inspectors who are experts at their work, capable of exercising independent judgment, and who are above suspicion. It is hopeless to expect to find such people among the ranks of the ordinary Chinese. The farmers whose stock and premises are to be inspected must also be people with some elementary notions of what is required of them. It need hardly he pointed out that no such state of affairs exists in China, and indeed, under present circumstances, is unthinkable, nor is it right that we in this country should run risks while a system of adequate inspection is worked out; in other words, that we should educate the Chinese farmer for his own benefit while running risks ourselves. It is stated that the stockyards and plant are well adapted for the work they have to do, and this we readily believe, but in an Oriental country in which there are no such things as health laws in existence, and where each man in this respect may do very much as seems right in his own eyes, the fact that we are obtaining from it an important article of food wherewith to feed large numbers of our poorer population is not one that can be viewed without serious apprehension as to the possible consequences. Stress has been laid on the fact that the pork is cheap, and that when an adequate system of inspection has been devised, the complete thawing out of the consignment will be no longer necessary and that Chinese pork will rank with the meat supplies that we obtain from the colonies. We have heard of the Greek Kalends, and it is possible that by the time they arrive the Chinese pig breeder and coolie will be a sufficiently cleanly person to be trusted with matters of this sort, but until that time does arrive we most strongly dissent from any line of action that would tend to shift any responsibility on to his shoulders. The pig is a dirty feeder, and the Chinese variety of the genus sus has the fullest opportunity for indulging his propensities for filth. He is also an animal peculiarly liable to various forms of disease of which swine fever is not the least objectionable. The care that is taken by the local authorities in this country regarding swine is sufficient evidence of this. But to make the British farmer conform to certain regulations while permitting pigs to be imported from China where no such regulations, or indeed, any at all, are enforced, seems to us to be the limit of hardship and absurdity. Sir PATRICK MANSON in the year 1881, at the request of the Chinese Government, made a careful examination of the bazaar pigs in Amoy. As a result of this examination he came to the conclusion that the flesh of such pigs was not sufficiently healthy to allow of its being safely eaten by Europeans at least. Though the proportion of pigs affected by Trichina spiralis was about 1 per cent., his conclusion was that with pork “cooked as the natives cook it, there can be little danger, but a roast leg of pork cooked in foreign style would certainly be a most dangerous dish.” The method adopted by natives was to cut the pork into small pieces and very thoroughly cook it. These were bazaar pigs, and of Amoy, which is far south of Hankow, but the bazaar pig in Hankow is probably not very different to his southern brother, and the conditions now in China are probably not much altered for the better since 1881. The pigs for the English market must be obtained from native breeders, and unless these breeders exercise unusual care in the feeding and housing of their stock, it is unlikely that any somewhat perfunctory system of inspection will do much towards‐mitigating the danger arising from The consumption of their pork It may be remarked that no people are more conservative than the Chinese, and to expect a Chinese peasant to radically alter his method of treating his stock, for reasons that he is entirely unable to appreciate, because there happens to be a market in England for the pork is really expecting too much. Nor does it seem that a consular invoice would be any real remedy. The time for insisting on consular invoices would probably be at the end of another series of “revelations,” and moreover, to attempt to make a consul professionally responsible for the soundness of large quantities of such pork, would be to impose a strange burden upon him.