PHP's rawurlencode and SEO

Is there any negative SEO impact when using PHP's rawurlencode() on names/titles in the url?

Also, if the name has an ampersand (&) in it, the name is being cut off at it. For example:

Before rawurlencode(): http://www.blah.com/Name1 & Name2/test.html

After rawurlencode(): http://www.blah.com/Name1%20%26%20Name2/test.html

The problem is, if I click on the link, it tries to load the page http://www.blah.com/Name1%20/test.html. As you can see, it cuts off the whole part "%26%20Name2"

Thanks!