how are quantum entangled states mantained? when ever I search for this question I always get articles on how to make a quantum entangled  pair, and not how it's kept or mantained. if i were to entangle a pair of electrons, how would I keep the particles entangled for long distances? 
 A: Short answer
I theory, it is easy to maintain the entanglement of two particles: just do nothing.
In practice, doing nothing is much harder than it sounds. You need to isolate both particle, so that their entangled degree of freedom (typically the spin for an electron) does not interact with anything else. It is hard to do with electrons, since they are charged and interact with the environment. That’s why most entanglement experiments use photons: they do not interact much, and travel fast, allowing do demonstrate long distance entanglement even if they live shortly. 
When one needs to keep entanglement for some time, electrically neutral material systems (cold atoms, crystal defects, etc) an relatively complicated protocols can be used. 
An explicit protocol involving entangled states of NV centres in diamond
I give below, an explicit protocol¹ considered by experimentalists to create and maintain entanglement in NV-centres in diamond. As you could easily guess from the description, this protocol is specific for this kind of experimental system, and has to be seen as an example, and a way to convince you that there is no short simple answer to your question (beyond “keep your system isolated”). If one is concerned by entanglement in cold atom vapours, neutrons, or supraconducting qubits, the protocols will look different, at least superficially, but is often as complex. 
Let us look, for example, at a protocol to entangle two NV-centres in diamonds located far away (a system recently used for a Loophole free test of Bell’s inequalities). 
At each location, an entangled state can be created between the spin of an electron and a photon. To maintain the entanglement, the state of each electron spin state can be mapped, through carefully crafted microwave pulses, to a more isolated nuclear spin state. The two photons are measured together in an intermediate place, effectively teleporting one photon to the spin entangled with the other. After photon measurement, the two nuclear spins are entangled, and can be maintained as long as the nuclear spins doe not interact with (chemical or isotopical) impurities in diamond (i.e. a few ms at room temperature). To perform measurements on the entangled states, one needs to use microwave pulses map the nuclear spin state to the electronic spin state, and then optically probe the NV centres.
Footnote:
¹: All the element of this protocol have been demonstrated in various combinations, but I don’t think the whole protocol above has been demonstrated yet. I know however that it is on the roadmap of several research groups.
