'Dyne With Me' explores surface tension of solutions used in everyday life. From inks to alcohol, drugs to dish soap, and everything in between....
Sunday, 29 May 2011
What the Frack?
So the video explains what fracking is. Fracking can get a lot more oil out of the ground than what is on the surface. This is the process of initiating, and subsequently propagating a fracture in a rock layer, employing the pressure of a fluid to remove the oil from the rock. A wide range of fluids from ionic surfactants to simple organics are pushed into the holes to bring up the oil. Research into better surfactants and potentially mixtures of surfactants are needed. These surfactants and simple organic chemicals like methane and benzene are required to change the surface tension of the oil and have it mix in the water for extraction.
Why do oil companies want to frack? There is still about 70% of the oil left in the ground after the oil wells have dried. So there are potentially trillions of dollars in unearthed oil. That is fracking fantastic right? Well all this fracking comes at a cost which is contaminating the water supply. These techniques have already devastated places in Pennsylvania and New York with widespread combustibles leaking into the water supply.
In this BBC news video below one guy in the town who leased an oil company his land to frack on shows how methane is leaking in his water supply. He lights a match on top of the bottle and shows the methane flame. Well that is fracked up! The spokesperson for Cabot said, 'there was always methane in the water around these areas and the regulators found no problems with our practices.' Well that is really fracked up!
Methane and benzene when in water can easily be measured using a tensiometer or some other device. The surface tension of water as the blog is called is 72 dynes. When you add methane or other organic chemicals to water they should lower the surface tension compared to pure water. The methane on the surface of the water can both lower the surface tension of the water and make the water flammable. Now that is fracked up!
(Oil or water you decide)
Friday, 27 May 2011
Utö: The Burial Ground for Ships and Training Ground for Membrane Scientists
This is a map and not membrane domain formation on a LB trough |
The Finnish archeapelago has a plethora of islands. These islands were the battle grounds between Russia and Sweden. If you are traveling from Turku to Stockholm you would run into the island of Utö. The bare, rocky islands of Utö are the main gateway to the Archipelago Sea. Since the 17th century, it has been a base for pilots, lighthouse keepers, custom officials and soldiers. So it was a strategic post for war ships. Many lighthouse operators were there during Swedish, Russian and Finnish rule. The Finnish military left the island in 2005.
If you fast forward to next week (June 4th-11th) you have a small island with a handful of residents who are going to be bombarded by a different breed of warrior, membrane scientists. The Molecular Engineering Summer School will take place here. It will be a place to learn about Biophysics of lipids and lipid-protein interactions: from biomembranes to molecular engineering, drug delivery and imaging. Check out the program here:
http://www.becs.tkk.fi/mess/index.html
Thursday, 26 May 2011
Surface tension for first graders
I have three nieces and a younger brother and sometimes it is nice to explain to them what I do when ask about my job. So one way to explain my job as a scientist (mad scientist I like to say to them) is by doing experimentation. Here is one experiment that can explain surface tension without any devices. Unfortunately in Europe we do not have pennies so I had to get one from an American friend.
Materials
- Penny
- Water
- Paper towel (or small dish)
- Medicine dropper (or plastic pipette)
- salt,
- dishwashing detergent,
- clean glass jars (or beakers),
- measuring spoons.
Procedure
1) How many drops of water will fit on a penny before the water runs off? You can calculate the prediction by measuring the area of one drop with a ruler and calculating the surface area of the penny.
2) Place the penny on a piece of paper towel (or on a small dish)
3) Drop water onto the penny using the medicine dropper (or pipette), counting the number of
drops as you go. Be consistent with the drops because there can be some variation. Also use the same penny for all the experiments head side up.
4) Keep dropping water and counting the drops until the water finally runs off the penny.
5) Record the number of drops in a table (the last drop that caused the water to run off
should not be included in your total).
6) Perform a second trial (I get them to do about 30 for good statistical averages and to account for variations in the drop size), record the number of drops in the table, and calculate the average
number of drops that the penny held in your trials.
7) Compare your results to your calculated prediction. Repeat but add a surface tension lowering substance like a drop of dish soap (1 drop of liquid dishwashing detergent in 1 liter of water; do not shake–cap the container and gently tip it back and forth to mix. Or add different concentrations of salt 1 teaspoon in 100 mL of water vary it with 1/8, 1/4, 1/2 a teaspoon or whatever.
Aux 8) coat the penny with some vegetable oil
Why does this work?
The cohesive forces of the water will allow it to stay on the surface of the penny. The roughness of the penny and if there are any surface irregularities or dirt will have an effect. The one thing that is important here is that the water does not roll off the penny until the penny is completely covered. The salt (if it is sodium chloride it might depend on the type of salt e.g. Hofmeister series ) will raise the surface tension slightly whereas the detergent will lower surface tension (that's how we clean dishes). Coating the penny in vegetable oil will repel the water from the surface of the penny as the vegetable oil is hydrophobic.
Postscript: Although amazed the kids still do not have a clue what I do.
Postscript 2: If you are a first grade teacher teach the kids how to draw a proper raindrop (see other post about this)
Peruvian Kidney Donors
So I talked about the use of surface tension for vaginal and seminal fluids. I then touched upon Zombie blood without any really understanding the answer for the latter. Lastly I found that surface tension has been used as a simple test for jaundice. Can surface tension be used for other medical and diagnostic applications?
I recently went to a talk by Prof. Paul Janmey from the University of Pennsylvania. His group works with the mechanical properties of the cell membrane and proteins associated with the membrane. He explained in his talk why it was difficult to grow neurons originating from stem cells in a glass jar. I quickly got the idea that Richard Nixon's head in a glass jar in Futurama. The brain cells (and other organ cells like kidney cells) closer to the glass do not represent healthy brain cells but the ones surrounded by brain cells are more likely to be closer to what we have in our brain. The glass may not be the right material in which to grow these cells for proper differentiation.
I recently went to a talk by Prof. Paul Janmey from the University of Pennsylvania. His group works with the mechanical properties of the cell membrane and proteins associated with the membrane. He explained in his talk why it was difficult to grow neurons originating from stem cells in a glass jar. I quickly got the idea that Richard Nixon's head in a glass jar in Futurama. The brain cells (and other organ cells like kidney cells) closer to the glass do not represent healthy brain cells but the ones surrounded by brain cells are more likely to be closer to what we have in our brain. The glass may not be the right material in which to grow these cells for proper differentiation.
One parameter that Janmey's group looked into was the cell mechanical stiffness. As explained in their abstract: 'The mechanical properties of cells and extracellular matrices are critical determinants of function in contexts including oncogenic transformation, neuronal synapse formation, hepatic fibrosis and stem cell differentiation.' Janmey's group found that many tissue samples are heterogenous with a length scale existing between the micrometers to millimeters. Current commercial instruments were only good for centimeter or nanometer (nanometer scale instruments like atomic force microscopy, optical trapping and magnetic bead microrheometry). So what do scientists do when they cannot find a solution? They invent one.
With the help of a Kibron tensiometer (micronewton resolution force probe) and a micromanipulator for probing soft biological samples at sub-millimeter spatial resolution. Janmey's group described several applications one interesting one being the quantification of the inner wall stiffness of healthy and diseased mouse aortas. They also showed stiffness of an intact, isolated mouse glomerulus (a capillary tuft that performs the first step in filtering blood to form urine in the kidney). This device could potentially one day grow new kidney's originating from a self donor in the presence of materials (unlike glass) that would represent actual kidney tissue that can then be transplanted. The usefulness of this device could one day grow kidney's so Americans would not need to illegally buy them from Peruvian donors.
Labels:
glomerulus,
kidney,
new instrument,
static surface tension,
stem cell
Wednesday, 25 May 2011
Great balls of......water
I showed you how the surface tension of water in space allows for water balls. These balls can also be achieved due to the strong surface tension of water on specialized surfaces. On a superhydrophobic surface the same thing happens and balls of water are in fact made. These balls of water can be electrostatically charged and manipulated. Hydrophobic meaning 'water hating' are surfaces that cause water not to spread out all over the table like your spilled beer. Rather it allows the solid surface to be repel the wettability of the water. The water then looks like a ball in this picture below:
with a contact angle (between the solid surface, air and water) is trying to go to around 180 degrees. A natural superhydrophobic surface is that of a lotus plant. Its waxy leaves repel water giving what they term The Lotus Effect. This Lotus Effect self cleans the lotus plant allowing dirt to be removed and increasing the accessibility for photosynthesis.
With the adhesion of silica nanoparticles, contact angles as high as 162° are achieved. Using silica nano-particles is also of interest to develop transparent hydrophobic materials for car windshields and self-cleaning windows, jeans that do not get dirty or microfluidic devices like some dudes at Aalto possibly want to build after making this article.
Reposted from here:
http://sci.aalto.fi/en/current/news/view/2011-05-09-006/Water drops move on water-repellent trackss like marbles in our childhood toys
09.05.2011
Researchers at Aalto University have developed a simple and efficient method for moving liquid drops in an almost totally water-repellent track. Drops move in open tracks, machined in metal or Si wafers, using gravity or using electrostatic charge. There is also a possibility to split drops in two with a blade mechanism developed for the track. For the droplet transport method now developed, there are excellent application possibilities, for example, in biochemical and medical analysis devices. The research findings have been recently published in Advanced Materials, a respected scientific journal.
Digital microfluidics, a relatively new field in microfluidics, studies controlling and analyzing single liquid droplets instead a continuous flow of liquids in channels. The research requires a multidisciplinary approach, and thus, it has been performed in cooperation and interaction between physicists and chemists from Aalto University, University of Helsinki and Technion (Israel).
“Future analysis devices may employ the presented method because of the low cost and efficiency of the droplet transport.”, tells undergraduate student Henrikki Mertaniemi, who performed the research under supervision of Dr. Robin Ras (Molecular Materials group, Dept. Applied Physics) in the context of his special assignment.
Link to the publication: http://dx.doi.org/10.1002/adma.201100461
Links to the videos showing water drops passing multiple curves in a superhydrophobic track with a width of 1.5 mm. The plate is tilted only slightly.
Superhydrophobic knife
Electrostatic actuation of a water droplet in a superhydrophobic track:
Superhydrophobic Track (soon kids will be playing with this everywhere)
Labels:
Aalto,
lotus effect,
lotus plant,
superhydrophobic surfaces,
water
Saturday, 21 May 2011
Surface Tension of Zombie Fluids
Who said zombies are not real? With the CDC (Center for Disease Control) releasing their hand Preparedness 101: Zombie Apocalypse I am starting to think that zombies could be real. So check out the link or follow this advice from Munz et. al who developed a mathematical model of a zombie outbreak. Are you ready? In any case watch AMC the Walking Dead.
Surface tension the molecular forces holding water together........so what does it have to do with zombies? I can really only speculate on what we have in nature on how zombie blood or other fluids surface tension might behave by a zombie infection (other causes are radiation and parasite). For simplicity in this case we will go with some infection albeit a mutated virus like Lyssa virus (rabies) that destroys the hypocampus and nervous system making the walking dead. It makes it a more interesting case since in the infected zombies the blood, nerves, and saliva, are all infected. So a zombie bite would be a communicative route of transfer.
What is the physiology of a zombie? You could probably just tell by looking at them. If you have seen the movies you should really go to this website for further explanation. Zombies are characterized by having the same strengths or abilities as they once had before infection e.g. strong men will be strong zombies. However, because they do not have a good feedback or feeling they may persist in doing certain tasks that normally (in an uninfected state you might not). A zombies agility is a little off since communication in the brain is not what it used to be. Zombies lack repair mechanisms for skin and broken bones. A zombies senses are also different since their eyes are less useful and rely more on smell and sound. Zombies also do not react to touch unless they grab it because of the severe nerve damage they have from the infection.
But for me and this blog I am interested in the...wait for it....surface tension. I have not seen anybody who has has mentioned anything about the blood or saliva of zombies. Would the surface tension be increased or decreased? I read a recent article by Rosina et al. that shows the difference in temperature of blood from 15 different subject by article it shows a linear regression of decreased surface tension (59-52 mN/m) at increased temperature as one might expect from 20-40 C. It is not quite clear whether (I guess it depends on the virus) will change the surface tension of blood and saliva. I cannot say anything about the saliva but the blood (based on the Rosina article) would probably have a lower surface tension because of the higher temperatures due to the fever. I would have to test this in the field or in the lab during a zombie apocalypse using some sort of awesome surface tension device. (shameless plug).
So what is the point of all this? Firstly it is to understand that blood and saliva might change its properties after a zombie attack. Understanding this would help in treating with a drug potentially and also just because it is interesting to understand something. Later you might find a potential use for that information. The second is whether you can prevent these fluids from entering your body using some kind of protection. This is recommended by the CDC manual and others suggest. Here is an standard method for Standard Test Method for Resistance of Materials Used in Protective Clothing to Penetration by Synthetic Blood. Some people actually recommended to useTyvek® garments which is a microporous material made by DuPont. Let me know if anyone reading this has any ideas on other solutions for protecting yourself or what the surface tension would be of a zombie's bodily fluids. As an uninfected scientist I want to know! Maybe Jonah Ray the from The Nerdist can help.
Labels:
blood,
DuPont,
rabies,
saliva,
static surface tension,
walking dead,
zombies
Thursday, 19 May 2011
Micro-origami blossoms
Coolest thing I have seen all day. You might think that I don't see a lot of cool things. But surface tension is cool isn't it?
Flottille (detail) from Etienne Cliquet on Vimeo.
Micro-origami blossoms on the surface of water by way of capillary action in the paper fiber.
Just wondering if you change the surface tension of the water and thus its wettability could you increase the rate of the blossoms opening?
Flottille (detail) from Etienne Cliquet on Vimeo.
Micro-origami blossoms on the surface of water by way of capillary action in the paper fiber.
Just wondering if you change the surface tension of the water and thus its wettability could you increase the rate of the blossoms opening?
CESIO
CESIO is going to be a good conference for surfactant manufacturers and testers of these surfactants.
http://www.cesio-congress.eu/practical.php
http://www.cesio-congress.eu/practical.php
Tuesday, 17 May 2011
What can Tyler Durden and Fight Club can tell us about Environmental Friendly Soap?
This human fat turns into... |
This ecological bar of soap. |
Tyler Durden: Now, ancient people found their clothes got cleaner if they washed them at a certain spot in the river. You know why?
Narrator: No.
Tyler Durden: Human sacrifices were once made on the hills above this river. Bodies burnt, water speeded through the wood ashes to create lye.
[holds up a bottle]
Tyler Durden: This is lye – the crucial ingredient.
Tyler was right about his soap history and the soap making process. The lye combined with the melted fat of the bodies, till a thick white soapy discharge crept into the river. Soaps for cleansing are obtained by treating vegetable or animal oils and fats with a strongly alkaline solution like lye. Fats and oils are composed of triglycerides: three molecules of fatty acids attached to a single molecule of glycerol. The alkaline solution, often lye, promotes a chemical reaction known as saponification. In saponification, fats are broken down (hydrolyzed) yielding crude soap. Fats are transformed into salts of fatty acids and glycerol is liberated, leaving glycerin as a byproduct. The hydrophobic amphipathic fats form micelles around the dirt on your clothes or skin and wash it away. Soap was traditionally made by a couple of different methods from saponifiable natural oils or fats from plants or animals viz. coconut, palm, cocoa butter, hemp oil, and shea butter, beef fat or the fat from sacrificed animals as the Roman's did. So when watching this movie over again with this information I developed more appreciation for Tyler Durden's home chemistry skills and later his love for the environment when I saw the next couple of scenes.
In the next couple of scenes Tyler Durden and well his alter ego Tyler Durden steal fat from the plastic surgeons office and make soap with lye? They mold it (also making the iconic picture for the movie shown above) and sell it to a major department store. 'Tyler sold his soap to department stores at $20 a bar. Lord knows what they charged. It was beautiful. We were selling rich women their own fat asses back to them. (Fight Club)'
So what does this have to with the environment, soaps and sustainability? As mentioned soaps are derived from natural sources (including fat women) which are renewable and sustainable. It was not until World War II that the price of soap increased significantly. The supply of these oils dwindled and synthetic detergents were produced to replace the demand. These synthetic detergents made from sodium salt of long chain benzene sulphonic acid or the sodium salt of a long chain alkyl hydrogen sulphate were also better to use because they did not leave a scum in hard water and also had better cleaning properties than natural soap.
Fast forwarding to the green revolution of today the synthetic detergents are deemed bad for the environment and not sustainable. So there are a number of things that formulators and environmental organizations are trying to do to reduce environmental impact:
Potential Solutions:
1) use less detergent in the washing process (making of tablets and washing machines that require less products and water)
Why?
People do not change so easily. Have you ever thought about how much soap you use? Most of the time you severely overestimate the amount. So industry made life easier. Just add a tablet and also changed the quantity of the product needed. Secondly, less water is used and less suds made with front end loading wash machines. I even think in Canada you get a tax rebate for switching to these machines.
2) change the formulations completely a) change the surfactant to sustainable surfactants, b) eliminate phosphates c) possibly many other things I have not thought about.
Why?
Firstly, detergents come from non-renewable petroleum which are not sustainable and possibly more costly as the price of oil and manufacturing of surfactant product increases (e.g. Shell is a major supplier of the surfactant business). Several new measures by the biggest surfactant suppliers Cognis, Total and Seppic have tried to use APG (alkyl polyglucoside). This non-ionic surfactant derived from vegetable oil and starch has been particularly successful in the last few years to make greener more sustainable surfactants and formulations. These surfactants and formulations physicochemical properties need to be tested quickly for efficacy so the brand image can give the same cleaning properties or better than before.
Secondly, companies have to think about the cradle to grave of their products today. Once the soap leaves your sink and goes down the drain you would want it to decompose and not leave an environmental impact. Measures to make sure these surfactants are biodegradable (cleaved by certain enzymes in the environment) have been made. The wonderful properties of phosphates made synthetic detergents a lot better. However, phosphates are a problem since they have increased the amount of algae in many ponds. Phosphates are now banned in 19 US states. So today's soaps contain new surfactants to reduce the amount and environmental impact on the environment.
So why does Tyler Durden love the environment? Tyler Durden's lye and human fat solution is nonetheless environmentally friendly alternative to manufactured detergents and cheaper to make then using natural ingredients from plants. It is phosphate free, biodegradable and because it is made from the fat of humans then it is sustainable.
Labels:
Detergent,
Ecological,
Fight Club,
Soap,
Surfactant,
Tyler Durden
Wednesday, 11 May 2011
Harder than your average water
I went on vacation to France recently and realized the natural shampoo that I bought well did not work as well. I had short hair so it was more noticeable when my girlfriend reported the same. I was wondering what the culprit and found it when I was making the morning coffee. On the inside of my kettle was white stuff at the bottom. This was not bacteria though it was calcium.
The water was hard!!! I found a French map of hard water areas with blue being very hard, followed by yellow, orange and the softest water being green. Hard water increases the surface tension of the water slightly as well as changes the properties.
In order for the detergent in shampoo to clean my hair the water has to be reduced so the water can spread out (also the water reduces its surfaces tension when heated) and soak into the surface of the hair. The shampoo reduces the surface tension of water and allow the water to mix with the dirt and grease (sebum) in your hair so it can be washed away. If the water is hard like mine in France determined how well (or poorly) my shampoo worked. The natural soap can formed a scum in the French water and did not rinse away easily. So I had to go to the store and buy some new shampoo with synthetic detergent. This synthetic detergent reacted less to the minerals in hard water but ended up stripping away all the natural oils from my girlfriend's hair. We did not really find a good solution for this. People can also use a vinegar rinse or use filtered water when they shower in places with hard water. Possibly detergent manufacturers might make better formulations for their detergents in different countries using tensiometers. These devices can help figure out the best amount of shampoo to use as well as change the shampoo for different regions in the world.
Tuesday, 10 May 2011
The death of a dinosaur
I do not know how scientists continue to purchase equipment that is very difficult to use, expensive and outdated. There is really no need for them when better instruments have replaced. That is the nature of science and technology isn't it? I do not see so many people using slide rule aka slipstick today. This device should have found its way to the land of obsolete a long time ago. So today I heard that the CSC Tensiomat 21 tensiometer that they have been making for decades is being discontinued.
So there is one less surface tension company that:
a) sells instruments with really expensive bendable rings
b) that frustrates students to use
c) gives confusing results that are not reproducible (partly because of a and lot to do with b)
I would rather use something that works like it was built for the 21st century.
So there is one less surface tension company that:
a) sells instruments with really expensive bendable rings
b) that frustrates students to use
c) gives confusing results that are not reproducible (partly because of a and lot to do with b)
I would rather use something that works like it was built for the 21st century.
Tuesday, 3 May 2011
The Unequivocal Structure of Heroin
Heroin named after the German word for powerful, heroic, heroisch may give the pleasure of “drinking a hundred bottles of whiskey while someone licks your tits (Midge Daniels MadMen Season 4 Episode 12)''
Heroin diacetylmorphine also known as diamorphine, is a semi-synthetic opioid drug synthesized from morphine, a derivative of the opium poppy. Heroin was made from the opium poppy which up to this point was used prior to the 19th century as a recreational drug in Mesopotamia. Opium's pharmaceutical properties were discovered later to consist of both morphine and codeine. Both of these has been used for a long time and even today as a pain killer. However, later in the 19th century it was experimented to find a variation of morphine and codeine. Heroin was first made by C. R. Alder Wright in 1874 where he noticed that the dogs he injected with the substance behavior begin to change immediately. Their behavior and physiology were similar to what you would have seen in Ewan McGregor in Trainspotting: fear, great prostration, sleepy, and loss of coordinated muscle movements (and possibly constipation). This research was largely forgotten until diamorphine was synthesized by a German chemist at Bayer. The same guys that gave aspirin were also the guys that distributed heroin as a non-addictive morphine substitute and cough suppressant! Heroin was possibly more addictive than its natural father.
So why is heroin so great and why am I talking about it? The answer lies in its absorption properties and its pharmokinetics. These can be understood by the putting the drug in water and understanding its properties at the interface mapping its true surface area. This property investigates whether a drug can get into and through a membrane like the blood brain barrier (BBB), intestine or possibly the skin.
So doctors and drug addicts both know that heroin can get to the brain faster than morphine because of the acyl groups on it. Heroin is the most fast-acting of all the opiates. When injected, it reaches the brain in 15-30 seconds; smoked heroin reaches the brain in around 7 seconds. The peak experience via this route lasts at most a few minutes. This makes heroin is one hell of a drug and usually the best drugs especially the drugs that affect the mind are sadly abused recreationally and also this drug by our society. Also like many psychoactive or nervous system drugs heroin is highly addictive. However, what makes a drug good enough to get into the brain? As I mentioned briefly when talking about Anne Peniette's paper a good drug to affect the brain needs to have the correct physiochemical properties and likely the correct shape to enter through the BBB. Replacing the two hydrogen-bonding -OH groups with -OCOCH3 (see below with the two groups on the left) makes heroin much less soluble in water than morphine, but more soluble in non-polar solvents, like oils and fats!!
Heroin is injected directly into the bloodstream, but once there it can pass rapidly through the blood-brain barrier which normally prevents the passage of water-soluble and large molecules. As a result it is much more potent than morphine, but its effect does not last as long. Again, once the heroin molecule is absorbed into the body, the acetyl groups are removed, reforming morphine.
Heroin diacetylmorphine also known as diamorphine, is a semi-synthetic opioid drug synthesized from morphine, a derivative of the opium poppy. Heroin was made from the opium poppy which up to this point was used prior to the 19th century as a recreational drug in Mesopotamia. Opium's pharmaceutical properties were discovered later to consist of both morphine and codeine. Both of these has been used for a long time and even today as a pain killer. However, later in the 19th century it was experimented to find a variation of morphine and codeine. Heroin was first made by C. R. Alder Wright in 1874 where he noticed that the dogs he injected with the substance behavior begin to change immediately. Their behavior and physiology were similar to what you would have seen in Ewan McGregor in Trainspotting: fear, great prostration, sleepy, and loss of coordinated muscle movements (and possibly constipation). This research was largely forgotten until diamorphine was synthesized by a German chemist at Bayer. The same guys that gave aspirin were also the guys that distributed heroin as a non-addictive morphine substitute and cough suppressant! Heroin was possibly more addictive than its natural father.
So why is heroin so great and why am I talking about it? The answer lies in its absorption properties and its pharmokinetics. These can be understood by the putting the drug in water and understanding its properties at the interface mapping its true surface area. This property investigates whether a drug can get into and through a membrane like the blood brain barrier (BBB), intestine or possibly the skin.
So doctors and drug addicts both know that heroin can get to the brain faster than morphine because of the acyl groups on it. Heroin is the most fast-acting of all the opiates. When injected, it reaches the brain in 15-30 seconds; smoked heroin reaches the brain in around 7 seconds. The peak experience via this route lasts at most a few minutes. This makes heroin is one hell of a drug and usually the best drugs especially the drugs that affect the mind are sadly abused recreationally and also this drug by our society. Also like many psychoactive or nervous system drugs heroin is highly addictive. However, what makes a drug good enough to get into the brain? As I mentioned briefly when talking about Anne Peniette's paper a good drug to affect the brain needs to have the correct physiochemical properties and likely the correct shape to enter through the BBB. Replacing the two hydrogen-bonding -OH groups with -OCOCH3 (see below with the two groups on the left) makes heroin much less soluble in water than morphine, but more soluble in non-polar solvents, like oils and fats!!
Heroin is injected directly into the bloodstream, but once there it can pass rapidly through the blood-brain barrier which normally prevents the passage of water-soluble and large molecules. As a result it is much more potent than morphine, but its effect does not last as long. Again, once the heroin molecule is absorbed into the body, the acetyl groups are removed, reforming morphine.
Labels:
Bayer,
BBB,
heroine,
static surface tension,
true surface area
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