Hello. Carbon fiber composites are incredibly lightweight and strong, as well as resistant to chemical damage and can have wide application, which made me a big fan of it. However as science progresses better materials are discovered and one the most interesting is graphene. Graphene has many amazing qualities such as having the best weight to strength ratio, is transparent when thin, has excellent thermal and electrical super conductivity, it could make better camera sensors, batteries, lights, computers and so on. Problem is that it‘s very rare new material on the market and is still hard to manufacture in large quantities. But just 1% of it in addition to concrete could make it 35% stronger. Some applies to it‘s powder being added into plastics and resin to make carbon fiber composites with unmatched weight to strength ratio. There is company Dassi that already makes carbon fiber with graphene bicycle frames that can weigh just 350 grams. So I thought it would be great to make for example a stronger carbon fiber case for phones which also could dissipate heat well which is bad for battery, camera sensor and other components. I noticed few companies on Ebay are selling graphene powders however it‘s pretty pricey at least now. Moreover there was an article about testing of commercial graphene and most samples were of bad quality - most contained less than 10% graphene flakes, with only one sample containing more than 40%.
Although it may be possible to make own cheaper graphene in large amounts but older methods are problematic. One of the interesting newer methods is Joule heating of any high carbon containing material (yes even trash plastic) in quartz tube to 3000 degrees of Celcius by applying capacitor high current electricity for seconds to break all bonds. Carbon then naturally assembles into graphene structure and other sublimed materials escape as gas, wolla you get treasure material. The bigger graphene flakes the stronger the composite can be.
https://phys.org/news/2020-01-lab-trash-valuable-graphene.html

Also an important factor is what type of carbon fiber and resin is used. Some carbon fibers can have better tensile strength or stiffness specs. Less dense resins can shave off weight additionally but is it worth over using regular transparent epoxy to make carbon fiber composites with graphene? It‘s important that it wouldn't be too toxic to breath and work with indoors, preferably crystal clear for wider application.

Sort of missed this post, but it is an interesting discussion.

For me, I feel like it is sort of in the same boat as Nanotubes when it comes to how useful it is in composites. Composite structures like carbon fibre are really at their best when you minimise the influence of the resin, and maximise the influence of the fibre. Which ideally means, less resin content, higher fibre content. When you add graphene or nanotubes or any of these high performance nano materials, you are really only influencing the performance of the resin matrix and not the performance of the fibres themselves. In a high performance composite where you ideally have less than 40% resin content (and that's really on a commercial level, high end structural pre-pregs and the like are getting down below 25% resin content), say you manage to increase the strength of the resin matrix by 20%. That doesn't correspond to a 20% increase in the strength of the laminate, because the resin is less than half of the laminate. It also doesn't even necessarily correspond to a smaller fraction of the strength, depending on properties you are measuring. It is not going to heavily influence the tensile strength of the laminate for example, because tensile strength is mainly dependent on the fibre. It would have more of an influence on the compressive strength of the laminate, as the resin matrix has more influence on that property. So realistically, the actual performance increase on the laminate is quite negligible. 

The argument for nanotubes has always been ''any performance increase is beneficial'', which is a fair point. And I would say if budget wasn't part of the question and you were just trying to achieve the maximum performance properties possible, then sure, probably add some nanotubes or graphene or whatever your chosen poison is and get those little gains in performance. But when you're factoring in price, the cost of the laminate vs the performance of the laminate don't really go up together in a linear fashion, so that's where the benefit of the additives becomes questionable.