The speed of light has come to 3-D printing. Northwestern University engineers have developed a new method that uses light to improve 3-D printing speed and precision while also, in combination with a high-precision robot arm, providing the freedom to move, rotate or dilate each layer as the structure is being built.
Most conventional 3-D printing processes rely on replicating a digital design model that is sliced into layers with the layers printed and assembled upwards like a cake. The Northwestern method introduces the ability to manipulate the original design layer by layer and pivot the printing direction without recreating the model. This “on-the-fly” feature enables the printing of more complicated structures and significantly improves manufacturing flexibility.
“The 3-D printing process is no longer a way to merely make a replica of the designed model,” said Cheng Sun, associate professor of mechanical engineering at Northwestern’s McCormick School of Engineering. “Now we have a dynamic process that uses light to assemble all the layers but with a high degree of freedom to move each layer along the way.”
An international team of researchers, affiliated UNIST has introduced an exiting new organic network structure that shows pure organic ferromagnetic property at room temperature. As described in the CHEM journal this pure organic material exhibits ferromagnetism from pure p-TCNQ without any metal contamination.
This breakthrough has been led by by Professor Jong-Beom Baek and his research team in the School of the Energy and Chemical Engineering at UNIST. In the study, the research team has synthesized a network structure from the self polymerization of tetracyanoquinodimethane (TCNQ) monomer. The designed organic network structure generates stable neutral radicals.
For over two decades, there has been widespread scepticism around claims of organic plastic ferromagnetism, mostly due to contamination by transition metals. Extensive effort has been devoted to developing magnets in purely organic compounds based on free radicals, driven by both scientific curiosity and the potential applications of a ‘plastic magnet’. Excluding the contamination issues and realizing magnetic properties from pure organic plastics must occur to revive the quest for plastic magnetism.
A green method for producing crystalline supramolecular fibers promises to make polymer production more sustainable.
A polymer that catalyzes its own formation in an environmentally friendly solvent-free process has been developed by an all-RIKEN team of chemists. The discovery could lead to the development of inherently recyclable polymer materials that are made using a sustainable process.
Polymers are ubiquitous today, but they are detrimental to the environment through the accumulation of plastic waste and the unsustainable nature of conventional polymer manufacture. Polymers are generally made by linking together strings of building blocks, known as monomers, using covalent bonds. But these strong bonds make it difficult to take used, end-of-life plastic items and de-polymerize them to recover the monomers for reuse.
The group at Polymeric Materials has developed a simple way to regulate both dispersity and sequence in highly complex multiblock copolymers, and the results have been published in Nature Chemistry.
Controlling monomer sequence and dispersity in synthetic macromolecules is a major goal in polymer science as both parameters determine materials’ properties and functions. However, synthetic approaches that can simultaneously control both sequence and dispersity remain experimentally unattainable.
In this contribution from the group at Polymeric Materials we present a simple, one pot and rapid synthesis of sequence-controlled multiblocks with on-demand control over dispersity while maintaining a high livingness, and good agreement between theoretical and experimental molecular weights and quantitative yields.
Currently the polymer chemistry I am working on is focused on the synthesis of kind of material called an Interpenetrating Polymer Network, or IPN for short. Without any particular bragging, this kind of material is particularly hard to synthesize because it essentially involves running two reactions at the same time. Allow me to explain… Polymeric materials are infamous for their inability to mix together. Without getting too hardcore into the physical chemistry or statistical mechanics, different polymer species do not mix together well. The general policy of “like with like” means that you are left with little collections of polymers clinging to each other in pods, resulting in an overall fragile material. Not quality for making a macroscopic product.
However, you -can- dissolve linear chain polymers in solution. And you can also frequently find ways to crosslink polymer chains together using standard organic (or inorganic, if you are really feeling freaky that day) chemical reactions. If you’re particularly clever, here’s where you can see the central idea behind IPNs. Basically, you take two polymer species that are soluble in the same solvent, and simultaneously crosslink them, like with like, so that you get a sort of polymeric mesh. Quite interestingly, the resulting material has the properties of both linear chains, much like a copolymer but without the pain of setting up a singular, living polymerization.
There are of course variations on this theme. They are simplified as follows: Semi-IPN: An interpenetrating polymer network where only one polymer species is crosslinked, and the other is left linear. The linear polymer, while dissolved, can float freely though the spaces in the crosslinked polymer. However, when the solvent is driven off it results in a material that has part of the properties of the crosslinked polymer, and part of the properties of the linear polymer. These do not combine as neatly as in a “full” IPN, giving distinct differences in Tg (Glass transition temperature), and other important physical properties.
Pseudo-IPN: An interpenetrating polymer network where one of the polymer species is already crosslinked from the beginning. From there, a linear polymer is added to the solvent, and allowed to get tangled up in the spaced between crosslinks. After a period of time (dependent on the materials you’re using), a crosslinking agent is added to the solution, causing the linear polymer chains to link together and form a mesh similar to the one produced by a simultaneous crosslinking. However, much like the semi-IPN, the product features uneven properties that cause lowered Tg, and difficultly during measurements determining important physical properties.
Full IPN: This is what happens when both linear polymers are simultaneously crosslinked in solution. The resulting product does not show clear signs of polymer separation, and has relatively distinct physical properties, such as a clearly determined Tg. Though, of course, this is the most difficult to synthesize.
My entire summer was spent in pursuit of a full IPN, and it’s likely that my entire fall will be spent in pursuit of novel full IPN design that will allow us to produce even more quality products.
A team of researchers from North Carolina State University has demonstrated a way to use low-energy, visible light to produce polymer gel objects from pure monomer solutions. The work not only poses a potential solution to current challenges in producing these materials, it also sheds further light on the ways in which low energy photons can combine to produce high energy excited states.
Polymer products—primarily plastics—are used in everything from water bottles to medical applications, with billions of pounds of these materials being produced annually. Select polymers can be produced via a process called free radical polymerization, in which a monomer solution is exposed to ultraviolet (UV) light. The high energy of UV light enables the reaction, forming the polymer. The advantages of this method include fewer chemical waste byproducts and less environmental impact.
However, this method is not without drawbacks. The high energy UV light used in generating these polymers can also degrade plastics and is unsuitable for producing certain materials.
i wonder if yu-gi-oh! fanfic authors realize that bringing back the pharaoh or the thief king in their original bodies would do way more harm than good because it’s been three thousand years and a completely different continent and i don’t think the gods are big on vaccines so even if they didn’t bring any ancient egyptian diseases back with them they’d probably die from the first breath of japan’s not-necessarily-unpolluted air or get an infection or something
Not if Yugi and Bakura get them into the doctor for their shots.
hello doctor this is my friend from ancient egypt and his mortal enemy they’ve been around for a while but now they’re corporeal so do you have a spare tetanus shot or are we doing this black market style
Of course, they’d have to come up with a fake background story and forged documents for them. Methinks Kaiba and Isis could help with that.
yuugi: hi kaiba those two ghosts you don’t believe in came back from the dead can you help forge some paperwork
kaiba: i don’t believe in any of this cra-
atem: i’ll duel you
kaiba: sign here and you’re legally a citizen
marik: isis can you-
isis: no
bakura: thank god i don’t care
rishid: you will when we all get measles
isis: ffffffffffffffffff
and everybody lived happily ever after mooching on kaiba because he didn’t care so long as yuugi dueled him and jounouchi was like five million yards away at all times
Listen but that’s most stories I’ve seen where they get their bodies back. If it’s not handwaved as they’re magical, Kaiba and Isis just do paperwork and get them vaccinated slightly questionably. Because this series is so wild, we know they actually would do this crap. And Malik is a mob boss. He could probably get a black market doctor/bribe one/pay one to give them shots.
This series has seen wilder.
you have better luck finding fanfics than i do, then
I mean, would it be so hard for them to go “these two were in an anti-vaxxer cult. They’re free and need vacinations pronto”?
yeah probably. this is yu-gi-oh! and your solution doesn’t involve even a single trading card game? unrealistic
Doctor: Yeah, okay, that’s a likely story. But I’ll tell you what. I’ll vaccinate you no questions asked…IF YOU CAN DEFEAT ME IN A DUEL *activates duel disk*
duel monsters: the only thing capable of overriding the hippocratic oath
4kids dubs dr malcolm practice to be a thinly veiled spoof of the jurassic park guy
it’s actually a joke i stole from the fifth artemis fowl book, not an attempt at tribute summoning jeff goldblum
w h o d o y o u h a v e t o f u s e i n e e d t o k n o w
