00:00:30 A tasty seafood dish. That's probably the way most of us think of mussels. To one person,

00:00:50 however, they mean a lot more than that. Biochemist Herbert Waite of the University of Delaware's

00:00:55 College of Marine Studies has discovered the chemical properties of mussel glue. That's the

00:01:00 sticky substance on the ends of threads mussels make for anchoring themselves to underwater rocks

00:01:05 and other objects. In other words, Professor Waite has discovered a unique super adhesive that can be

00:01:10 applied and stick underwater. What you need to stick to surfaces underwater is an adhesive that

00:01:17 can chemically and physically push the water molecules aside. The mussel adhesive does this.

00:01:23 The mussel produces this extraordinary glue in its so-called foot, an extendable tongue-shaped

00:01:29 appendage where it also makes the threads. Depending on water turbulence, the threads

00:01:33 can number anywhere from 7 to 200. Chemically, the glue produced by the mussel is one of the

00:01:39 toughest known. To many surfaces, the adhesion is irreversible. So if you were to pull on this glue,

00:01:47 it's more likely that you would break the tissue that it's attached to than the bonds to the

00:01:54 tissue. Presently, it takes thousands of mussels to produce minute quantities of the glue. But in

00:01:59 the future, if its chemical properties can be synthesized in quantity, the glue may be used in

00:02:04 a wide variety of applications. Dentists would like to know how to stick things onto teeth without

00:02:09 having to go to great lengths to dry them. People who work with boats and repair of boats at sea

00:02:17 would much prefer to repair them without dry docking them. And medically, synthetic mussel glue

00:02:23 might also be used for mending broken bones and torn tissue. For now, mussel glue remains in the

00:02:28 realm of biochemical research, but its potential has been well documented. Indeed, it is an adhesive

00:02:35 with plenty of mussel. On the science scene, I'm Alan Smith.

00:03:05 Some people think of the sumac tree or shrub as little more than a giant weed. It's found all over,

00:03:27 along highways, sprouting in residential areas, even pushing up around city sidewalks. Indeed,

00:03:33 it does seem to grow like a weed. At the U.S. Department of Agriculture, however, research

00:03:38 agronomists and chemists look at sumac in a different light. They've discovered chemicals

00:03:43 known as polyphenols in so-called smooth sumac, and they say these polyphenols have potential for

00:03:49 use in making a multitude of products. They can be used for the production of plastics,

00:03:53 they can be used for making polyurethane foam, they can be used for producing adhesives for

00:04:00 particle boards, and one very important constituent of smooth sumac is tannin,

00:04:06 which can be used in the leather industry. Ground into fine powder, the entire sumac plant can be

00:04:11 used to produce polyphenols, and then, if desired, tannin. While a commercial operation would be far

00:04:16 larger, this lab-scale apparatus demonstrates the process for polyphenols. The polyphenols

00:04:22 are drawn off from the powdered sumac inside by acetone, an inexpensive, reusable chemical. Later,

00:04:29 depending on the product to be made, say particle board adhesive, the extracted polyphenols would be

00:04:34 combined with formaldehyde. For producing tannin from certain polyphenols, another process and a

00:04:40 chemical agent would be used. There are, of course, other sources of polyphenols, but the great

00:04:46 potential of sumac is that it's a hardy plant farmers could grow with little attention. It can

00:04:51 be grown as a perennial crop, that is, it would stay in the field once established in the field,

00:04:57 would stay there year after year, and can be harvested as you would hay, like alfalfa hay.

00:05:03 While further chemical studies must still be conducted, researchers consider sumac's beneficial

00:05:09 chemical uses and its suitability as a crop as making this common plant a diamond in the rough.

00:05:15 On the Science Scene, I'm Alan Smith.

00:05:27 .

00:05:50 Diamonds may be a girl's best friend, but not the kind of diamonds they create at Pennsylvania State

00:05:55 University. Moreover, while synthetic diamonds have been around for years, scientists at Penn

00:06:01 State have recently refined a vapor deposition technique that chemically produces extremely thin

00:06:07 diamond films. Films, they say, that unlike synthetic diamonds, identically match the

00:06:13 properties of natural diamonds. These films or coatings may be employed in a variety of uses.

00:06:19 The applications of these thin films are really quite extensive, and they cover areas all the

00:06:27 way from cutting tools, drill bits, to microelectronic chips and optical coatings.

00:06:33 The Penn State technique for chemically coating diamond film on a surface, such as silicon,

00:06:38 involves passing mixtures of methane and hydrogen gases through a microwave plasma within the long

00:06:44 vertical tube of this equipment. The mixing is seen through a mirror that peers down into the

00:06:49 tube. The key here to producing pure diamond quality is to saturate the mixture with the

00:06:55 hydrogen. The entire process is a low-temperature, low-pressure technique, as opposed to the

00:07:00 high-temperature, high-pressure methods now used to make synthetic diamonds. With the Penn State

00:07:05 process, the film produced has all the properties of true diamonds, from extreme hardness to

00:07:11 excellent heat conductivity and electrical insulating ability, properties that could lead

00:07:16 to greater miniaturization in electronics. Using diamond, we can make the computer chips

00:07:22 even smaller than they are today, and we can get the devices closer together so that we may have

00:07:30 computers that are more like our hand calculators of today. While the Penn State chemical process

00:07:35 could indeed create diamond gems, its real purpose is to advance technology,

00:07:40 not produce expensive jewelry. On the Science Scene, I'm Alan Smith.

00:08:06 So

00:08:27 tree trimming is an expensive, ongoing operation for most utility companies,

00:08:32 but it's a necessary one to prevent growing branches from shorting out power lines or

00:08:36 interfering with line maintenance. Now, though, Potomac Edison, a Maryland-based utility company,

00:08:42 has come up with a safe chemical process for slowing the growth of trees. The system,

00:08:47 called ArborChem, was developed by the Asplund Company from the utility's specifications.

00:08:52 An injection process using a growth-regulating chemical, it's employed in conjunction with tree

00:08:58 Normally, we trim trees for power line clearance every two to three years. Use of a growth

00:09:05 regulator will reduce the frequency of trimming to every five, possibly every six years.

00:09:12 Using the growth regulator, the utility hopes to cut its tree trimming costs by more than

00:09:17 half a million dollars a year. Trimming one tree can cost as much as $90, while injecting a tree

00:09:23 with a slow growth regulator costs only $7 to $10. The procedure is safe and simple. The chemical,

00:09:30 which shortens the cells of the tree, is injected into the trunk from portable equipment.

00:09:34 The whole operation takes roughly 15 minutes, whereas trimming a tree can take as long as 90.

00:09:40 Moreover, the process and the chemical regulator won't harm the tree or the environment.

00:09:45 Ecologically, it's not harmful to the tree at all. In addition to going directly into the tree,

00:09:51 once the material's in the tree, all the movement is to the tree top, to the actively growing parts,

00:09:58 so that the possibility of groundwater contamination just does not exist, because

00:10:03 none goes into the soil. It all goes upward in the tree. In addition to safety, Mr. Watson says

00:10:08 treated trees are also more drought resistant, fight disease better, and make more efficient use

00:10:14 of their food. But the basic importance of this chemical process is pruning the cost of tree

00:10:19 trimming. On the Science Scene, I'm Alan Smith.

00:10:49 Most chemistry labs look much like this, crammed with all sizes and shapes of vials, burners,

00:11:10 beakers, and tubing. At Bowdoin College in Maine, however, the organic chemistry lab looks a bit

00:11:14 different. There, most of the equipment has been miniaturized, with the glassware fitting snugly

00:11:20 into one small kit. Using such equipment and revised process techniques, Bowdoin is teaching

00:11:26 chemistry at the micro-scale level. Like many innovations, the mini-lab concept grew out of a

00:11:32 problem. It was our desire to improve the atmosphere of the organic laboratory, which was causing a

00:11:38 considerable problem at Bowdoin. And in the beginning, we thought that what we would do

00:11:44 was to improve the laboratory air flow. But to do that meant a costly revamping of the lab's

00:11:50 ventilation system. So the Bowdoin Brain Trust took a different approach. Scale down chemical

00:11:55 reactions by developing miniature lab equipment and techniques that use but tiny amounts of

00:12:01 chemicals. Not only did this vastly improve lab air quality, but micro-scale chemistry is now

00:12:07 producing other benefits. Lower costs for chemicals, and because quantities used are so small,

00:12:13 fire and explosions are virtually impossible. But perhaps of greatest importance,

00:12:17 students are getting more out of their chemistry courses, and it's quicker and easier to do

00:12:21 experiments. It's turned out that it's a better way of teaching the subject. We find that

00:12:28 ultimately, we will probably cover just about double the amount of chemistry that we would

00:12:32 have in a single semester. In addition, students really do like the lab. After they come up into

00:12:37 the pipette, they'll separate. So there they go, a clear layer. Now on the top. Wow. Okay, squirt

00:12:45 the purple. Since Bowdoin launched its micro-scale lab system, many other schools have followed suit,

00:12:50 indicating, in chemical education at least, that bigger isn't necessarily better.

00:12:54 On the science scene, I'm Alan Smith.