Here is one book about it.
Some of this book is a bit of a stretch. However there a several characters that really make you think. The coincidence is too great. I'm not exactly sure what kind of conclusion you'll draw from this reading. It is my conclusion, however, that since pictographic languages need a point of reference, a picture, then it would make sense to base a pictographic language on something that the users are familiar with. If a house is a mud hut, the the symbol used for house may resemble a mud hut - not a log cabin. So one theory could be that at the time of the Tower of Babel, some people started developing a pictographic language that evolved into Kanjis. Please remember that Mandarin/etc is not the only language to use Kanjis. Korea, and Vietnam, and I think even Thailand used Kanjis. Most of them remain almost the same and have changed very little over the years.
This page disproves this theory.
Though, I will point out that whoever wrote that page is not familiar with Kanjis, or maybe even Asia in general. The argument that there were a lot more that 8 mouths on the boat is pretty lame. Most everyone who is familiar with Kanjis knows that the mouth glyph is often used to to represent a person.
Has anyone ever been to Japan? Do you notice that shrine they carry around during matsuris resembles the "Ark of the Covenant"?
Has anyone ever read Ethiopian text? It has characters that are the same and with the same pronunciation as Katakana.
I'm not trying to prove a point. I'm throwing out some not so discussed things. Maybe it will help people to think.
Kanjis are AKA Chinese characters. Though as you read above, China is not the only country to use them. Lots of Asia used them once upon a time.