Research Equipment § GC-Mass
GC is Gas Chromatography, which uses the different forces of each analyte on the static phase to achieve the separation effect. Using the different flushing times, the mixture is separated to produce "Pure Faction". Mass is the Mass Spectrometer mass spectrometer first ionizes the analyte to form a charged body, and then passes it through a corrected electric or magnetic field to obtain the mass and relative intensity of its fragmented ions. GC-Mass mass spectrometer ionization method: 1. Electron Impact Ionization by electron ionization method. It is currently the most commonly used ionization method, which can generate more fragmented fragments and obtain more complete structural information but will lose molecular weight information. Now all GC-Mass uses this method to make libraries. 2, chemical-free method. Compared with the "SOFT" (low energy) ionization method, it produces fewer broken fragments and can obtain molecular weight information, and detect positive and negative ions.
Experiment § Basic knowledge of halogen flame retardants (1)
According to many scientific studies, halogen-based flame retardants have become pollutants that spread everywhere in the daily environment, and the threat to the environment and human beings is increasing. The act of manufacturing, recycling, or throwing away appliances and other consumer products is the primary way these pollutants are released into the environment. In order to protect the environment, some halogen-based flame retardants can no longer be used in the plastic material part of electrical products and building materials (generally referring to the surface/shell of plastic). The reason for banning halogen-based flame retardants in plastic materials is that such flame retardants cannot be recycled, and they release harmful substances during combustion and heating, threatening human health, the environment, and future generations. Like other toxic heavy metals (such as lead, cadmium, mercury, hexavalent chromium, etc.), the European Union in the "Restriction of the Use of Hazardous Substances in electrical and electronic equipment" (RHS) decided to completely ban the use of brominated flame retardants such as PBB (Polybrominated Biphenyls) and PBDE (Polybrominated Diphenyl Ethers) on July 1, 2006. The most used halogen flame retardants are brominated flame retardants, most of which decompose at 200~300 ° C. During decomposition, the free radicals generated by capturing the degradation reaction of polymer materials will delay or terminate the chain reaction of combustion, and the liberated HBr is a kind of incombustible gas, which can cover the surface of the material and play the role of blocking the combustible gas on the surface. Brominated flame retardants have a wide range of applications and are currently one of the largest organic flame retardants in the world. The main products are decabromodiphenyl oxide, tetrabromobisphenolA, pentabromotoluene, hexabromocyclododecane, etc. Although brominated flame retardants are not the development direction of flame retardants, there is still controversy about the use of brominated flame retardants, especially in Europe. But in the Chinese market, brominated flame retardants still occupy the most important position. At present, brominated flame retardants still have indisputable superior performance in flame retardant effect. Although there is a debate on brominated flame retardants, it may take ten more years for this debate to form a global consensus or a government ban. But as a product, it can form a production and sales cycle in ten years.
—Data provider: Business Manager Mrs. Huang Zhu-Fang of Everwide Chemical
Knowledge § How about RoHS regulations?
RoHS (Restriction of Hazardous Substance) is a directive issued by the European Union and implemented after July 2006 on the prohibition and restriction of hazardous substances to control the negative impact of electrical and electronic products on the global environment. The RoHS Directive controls the use of heavy metals such as lead, cadmium, hexavalent chromium, mercury, and brominated flame retardants (PBBs and PBDEs) in electrical and electronic products. And their content should not be greater than the following values: cadmium/100ppm lead, hexavalent chromium, mercury, brominated flame retardants (PBBs and PBDEs)/1000ppm, electrical and electronic products that do not comply with the above-mentioned RoHS-controlled chemical substances cannot be placed on the market.
Product introduction § GN435-3
GN435-3 photocurable resin will react and form rapidly under the irradiation of visible light (436nm). The cured resin has the toughness and is especially suitable for fixing and bonding between different materials of glass and plastic. In addition, when laminating substrates with different expansion and shrinkage rates, the softness of the adhesive needs to be considered. GN435-3 light-curing resin has a good elongation rate to withstand the problems caused by high and low-temperature changes during lamination, and it has a good ring test result when a large area of glass has adhered to the acrylic, PC, ABS, and other plastics. The characteristics of GN435-3 are (1) High viscosity, good toughness, good shock absorption, and thermal shock resistance. (2) Good ductility and flexibility, and high-strength adhesion to glass and plastic substrates.
Living § Advice for graduates
Once I was invited to give a speech at a private university in the north, and the audience was a prospective graduate who took a certain course and was a senior. Before the speeches started, these audience members were rushing to the last few rows of the lecture hall. Some people bowed their heads to eat fried noodles, some people crossed their feet to copy homework, and some people were in close contact with their girlfriends. Seeing this kind of scene, I thought to myself that this phenomenon is not ideal, the audience is so indifferent, so I am not very interested in speaking. After finally talking for an hour and a half, the final open questioning stage was still too cold, and no one asked any questions. At this time, the teacher who invited me to speak stood up and asked a question. He hoped that I could give the graduates present a suggestion for entering the society. After an hour and a half of indifference, I decided to blow their self-confidence. "All students here, please raise your hands if you think that the starting salary of graduates from National Taiwan University is higher than yours." The vast majority of students raised their hands. "I would like to ask students, when did you know that the starting salaries of graduates at National Taiwan University are higher than you? Did you know it when you were a freshman, or did you know it now when you are about to graduate in your senior year?" Most of the students present said that in their freshman year they thought that the social and economic conditions of Taiwanese university students would be better than theirs. "May I ask everyone, did you make some efforts to prevent this from happening when you knew four years ago that the social and economic conditions would not be as good as those of Taiwanese college students?" But the audience was silent. "Please self-assess, after these four years, has the gap between you and Taiwan University students in terms of knowledge, ability, and other indicators narrowed or widened?" Still, the audience was silent. "I ranked last in the class in the first monthly test in high school, but I ranked second in the class in the joint entrance exam." "My university grades are about 20th in the class, but I got the first place in the entrance examination for the graduate school." "Although I have a doctorate degree, I attach great importance to the quality and quantity of my thesis, and I am determined to surpass Dr. Yang. " As can be seen from these experiences, I have never been a good student several times in my life, and I don't really know what it's like to be a winner. On the contrary, I was often undervalued in the first place. In this kind of situation, my reaction is not the same as others, and when others are playing leisurely, I will try to improve my skills. When others are forced to accept reality, I will try my best to save the best result. Many bad outcomes can be predicted from the very beginning. We often have plenty of time to avoid bad outcomes and bad outcomes are mostly due to our laissez-faire. The above three points are my advice to graduates in that speech. Although it was an impromptu performance, I was quite pleased with the on-the-spot reaction. Even the teacher who invited me to speak was full of praise. He praised me for daring to say what others would not dare to say. I hope the students can learn something.
─Author: Dr. Ming-Xu Li of Everwide Chemical
